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Codeine was microinjected into the area of the Kölliker-Fuse nucleus and the adjacent lateral parabrachial nucleus, within the pontine respiratory group in 8 anesthetized cats. Electromyograms (EMGs) of the diaphragm (DIA) and abdominal muscles (ABD), esophageal pressures (EP), and blood pressure were recorded and analyzed during mechanically induced tracheobronchial cough. Unilateral microinjections of 3.3 mM codeine (3 injections, each 37 ± 1.2 nl) had no significant effect on the cough number. However, the amplitudes of the cough ABD EMG, expiratory EP and, to a lesser extent, DIA EMG were significantly reduced. There were no significant changes in the temporal parameters of the cough. Control microinjections of artificial cerebrospinal fluid in 6 cats did not show a significant effect on cough data compared to those after codeine microinjections. Codeine-sensitive neurons in the rostral dorsolateral pons contribute to controlling cough motor output, likely through the central pattern generator of cough., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This is a nonclinical, controlled, and triple-blind study to investigate the effects of codeine-associated geraniol on the modulation of orofacial nociception and its potential central nervous system depressing effect in an animal model. The orofacial antinociceptive activity of geraniol in combination with codeine was assessed through the following tests: (i) formalin-induced pain, (ii) glutamate-induced pain, and (iii) capsaicin-induced pain. Six animals were equally distributed into six groups and received the following treatments, given intraperitoneally (i.p.) 30 minutes before the experiments: a) geraniol/codeine 50/30 mg/kg; b) geraniol/codeine 50/15 mg/kg; c) geraniol/codeine 50/7.5 mg/kg; d) geraniol 50 mg/kg; e) codeine 30 mg/kg (positive control); or f) 0.9% sodium chloride (negative control). We performed pain behavior analysis after the injection of formalin (20 µL, 20%), glutamate (20 µL, 25 µM), and capsaicin (20 µL, 2.5 µg) into the paranasal region. Rubbing time of the paranasal region by the hind or front paw was used as a parameter. In the neurogenic phase of the formalin test, the geraniol/codeine at 50/7.5 mg/kg was able to promote the maximum antinociceptive effect, reducing nociception by 71.9% (p < 0.0001). In the inflammatory phase of the formalin test, geraniol/codeine at 50/30 mg/kg significantly reduced orofacial nociception (p < 0.005). In the glutamate test, geraniol/codeine at 50/30 mg/kg reduced the rubbing time by 54.2% and reduced nociception in the capsaicin test by 66.7% (p < 0.005). Geraniol alone or in combination does not promote nonspecific depressing effects on the central nervous system. Based on our findings, we suggest the possible synergy between geraniol and codeine in the modulation of orofacial pain.

Background: Paracetamol, codeine, and tramadol are commonly used to manage mild pain, and their availability without prescription or medical consultation raises concerns about potential opioid addiction., Objective: This study aims to explore the perceptions and experiences of Twitter users concerning these drugs., Methods: We analyzed the tweets in English or Spanish mentioning paracetamol, tramadol, or codeine posted between January 2019 and December 2020. Out of 152,056 tweets collected, 49,462 were excluded. The content was categorized using a codebook, distinguishing user types (patients, health care professionals, and institutions), and classifying medical content based on efficacy and adverse effects. Scientific accuracy and nonmedical content themes (commercial, economic, solidarity, and trivialization) were also assessed. A total of 1000 tweets for each drug were manually classified to train, test, and validate machine learning classifiers., Results: Of classifiable tweets, 42,840 mentioned paracetamol and 42,131 mentioned weak opioids (tramadol or codeine). Patients accounted for 73.10% (60,771/83,129) of the tweets, while health care professionals and institutions received the highest like-tweet and tweet-retweet ratios. Medical content distribution significantly differed for each drug (P<.001). Nonmedical content dominated opioid tweets (23,871/32,307, 73.9%), while paracetamol tweets had a higher prevalence of medical content (33,943/50,822, 66.8%). Among medical content tweets, 80.8% (41,080/50,822) mentioned drug efficacy, with only 6.9% (3501/50,822) describing good or sufficient efficacy. Nonmedical content distribution also varied significantly among the different drugs (P<.001)., Conclusions: Patients seeking relief from pain are highly interested in the effectiveness of drugs rather than potential side effects. Alarming trends include a significant number of tweets trivializing drug use and recreational purposes, along with a lack of awareness regarding side effects. Monitoring conversations related to analgesics on social media is essential due to common illegal web-based sales and purchases without prescriptions., (©Federico Carabot, Carolina Donat-Vargas, Javier Santoma-Vilaclara, Miguel A Ortega, Cielo García-Montero, Oscar Fraile-Martínez, Cristina Zaragoza, Jorge Monserrat, Melchor Alvarez-Mon, Miguel Angel Alvarez-Mon. Originally published in the Journal of Medical Internet Research (https://www.jmir.org), 14.11.2023.)

Introduction: The inflammation and pain occur in all the wounds. Opioids drugs decrease pain and may act as an anti-inflammation. The current study was conducted to investigate the efficiency of the topical uses of Codeine on full-thickness excision wound models by focusing on relationship between pain mediators, inflammation and wound healing rate., Methods: Following the induction of anesthesia, a skin wound with a size of 7-mm punch was induced on the dorsal surfaces of each mouse. The mice were divided into five categories: groups I-III were daily administered 2.5%, 5%, and 10% Codeine gel; those in group IV were administered phenytoin cream, and group V (controls) received base ointment. To assess the effects of Codeine gel on the wound healing process, the wound area, histological parameters, and the relative protein expression of CXCR1, CXCR2, IL-6, IL-6R, PDGF, PDGFR, and COL1A along with the plasma concentrations of IL-1β, IL-10, and TNF-α were investigated on days 3, 7, and 14., Results: On days 7 and 14, the wound area was significantly lower in the treated mice compared to the controls (P < 0.05). Angiogenesis, collagen deposition, and epithelium thickness were significantly higher in the treatment groups compared to the control group (P < 0.05). The relative protein expressions of CXCR1, CXCR2, IL-6, and IL-6R and the plasma concentrations of IL-1β and TNF-α were significantly lower in the treated groups. Meanwhile, the relative protein expressions of PDGF, PDGFR, and COL1A and the plasma concentration of IL-10 were significantly higher in the treated mice (P < 0.05)., Conclusion: Administration of Codeine gel accelerated wound healing through decreasing the pain mediators, inflammation and promoting proliferative phase., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Background: Although codeine has been reported to enhance sexual activity by improving penile reflexes, it has been shown to impair fertility indices. Also, codeine impairs ovarian steroidogenesis and folliculogenesis. Nonetheless, whether or not codeine exerts an epigenetic effect remains unclear. On the other hand, arginine has been speculated to enhance penile reflexes by upregulating NO/cGMP Signaling., Aim: The study evaluated the effect of maternal codeine exposure and prepubertal codeine and arginine treatments on F1 male sexual function and fertility indices, as well as the outcome of F2 progenies. In addition, the epigenetic programming mechanism was also explored., Methods: Forty three-week-old female rats were randomized into two groups (n = 20 rats/group); the control that received 0.5 ml of distilled water and the codeine-treated that received 5 mg/kg of codeine via gavage for eight weeks. Afterward, the female rats were paired for mating with sexually mature male rats. Rats were maintained on their pre-pregnancy treatments throughout pregnancy and lactation. FI progenies from each cohort (control and codeine-treated cohorts) were weaned at three weeks and randomized into four groups; the control, codeine-treated, L-arginine-treated (300mg/kg), and codeine + L-arginine-treated (n = 10 rats/group). Administration commenced a week post-weaning and lasted for eight weeks via gavage., Key Findings: Maternal codeine exposure did not alter body weight, but significantly reduced anogenital distance and anogenital index of F1 male offspring. Also, maternal codeine delayed preputial membrane separation, impaired male sexual competence, and penile reflexes of F1 male offsprings. These were associated with reduced dopamine, gonadotropins, and testosterone levels as well as suppressed expression of androgen receptor mRNA. In addition, maternal codeine downregulated NO/cGMP signaling, impaired fertility indices, and reduced the litter size, weight, and survival of F2 progenies. These alterations were observed to be aggravated by prepubertal codeine exposure but improved by prepubertal arginine treatment., Significance: In conclusion, codeine programmed sexual dysfunction by suppressing the levels of dopamine and testosterone, as well as repressing the expression of androgen receptor mRNA. In addition, codeine-induced epigenetic reprogramming was expressed in the F2 offsprings as reduced litter size and weight, and survival rate. Notably, these observations were worsened by prepubertal codeine exposure, but dampened by prepubertal arginine treatment., Competing Interests: The authors have declared that no competing interests exist.

This study evaluated the orofacial antinociceptive effect of (S)-(-)-perillyl alcohol (PA) associated with codeine (C) and investigated the possible molecular anchorage mechanisms of PA. Mice (n = 5 per group) were treated with PA alone and associated with codeine and assigned to the following groups: 75.0 mg/kg PA; 75.0 mg/kg PA + C 30 mg/kg; PA 37.5 mg/kg + C 15.0 mg/kg; C 30.0 mg/kg; and control. Nociception was induced by formalin, capsaicin, and glutamate, and was quantified based on the duration (in seconds) of face grooming. The possible mechanisms of action were evaluated by molecular docking study. In the formalin test, PA75/C30 presented an effect in the neurogenic (p < 0.0001) and inflammatory (p < 0.005) phases. Mice treated with PA75 (p < 0.0001) and PA75/C30 (p < 0.0005) showed a reduced nociceptive behavior in the capsaicin test. Glutamate-induced nociception also was blocked by PA75 (p < 0.0005) and C30 (p < 0.0005). The molecular anchorage analysis indicated high negative binding energy values for the evaluated receptors, especially glutamate receptors (AMPA -79.57 Kcal/mol, mGLUR6 -71.25, and NMDA -66.33 Kcal/mol). PA associated with codeine showed orofacial antinociceptive activity, with theoretical evidence of interaction with glutamate receptors.

Ethnopharmacological Relevance: Erigeron canadensis has been used in traditional medicine to treat a variety of respiratory diseases, including acute upper and lower respiratory tract infections and cough-related asthma. There is as yet no relevant experimental or clinical study in the scientific literature evaluating the efficacy of plants in these disorders., Aim of the Study: To investigate the active ingredients in Erigeron canadensis, a complex isolated from flowering parts of a plant was tested for airway defense reflexes, in particular for cough reflexes and airway reactivity. Both were experimentally induced by a chemical irritant that simulated the inflammatory conditions of their formation., Material and Methods: The polyphenolic polysaccharide-protein (PPP) complex was isolated from the flowering parts of Erigeron canadensis by hot alkaline extraction and a multi-stage purification process. The antitussive activity was confirmed as a decrease in the number of citric acid-induced coughs and the bronchodilator effect was verified as a decrease in specific airway resistance (sRaw) in conscious guinea pigs., Results: The dark brown Erigeron complex with a molecular weight of 38,000 g/mol contained phenolics (13.2% wt%), proteins (16.3% wt%), and uronic acids (6.3% wt%). The neutral carbohydrate part of Erigeron consisted mainly of xylose (12.1 wt%), glucose (13.3 wt%), arabinose (24.1 wt%), and galactose (41.0 wt%) residues. Arabinogalactan and 4-OMe-glucuronoxylan have been found to be the major polysaccharides in the Erigeron complex. Using a method of chemically-induced cough reflex and guinea pigs test system the Erigeron complex exhibited statistically significant, the dose-dependent antitussive activity, which was similar to that of the centrally-acting opioid agonist codeine., Conclusion: Pharmacological tests have revealed a new pharmacodynamic effect of the Erigeron complex, namely an antitussive effect. Its activity was most pronounced in comparison with all previously tested compounds from other medicinal plants and approached the effect of codeine, the most potent antitussive used in clinical practice. The results provide the scientific basis for the application of this herb in traditional medicine., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background and Aim: Opioid receptors agonists have been demonstrated to impair lower esophageal sphincter (LES) relaxation and induce spastic esophageal dysmotility, but little was known for their impact on distension-induced secondary peristalsis. The aim of the study was to investigate the hypothesis whether acute administration of codeine can influence physiological characteristics of primary and secondary peristalsis in healthy adults., Methods: Eighteen healthy volunteers (13 men, mean age 27.5 years, aged 20-43 years) underwent high resolution manometry (HRM) with a catheter containing an injection port in mid-esophagus. Secondary peristalsis was performed with 10 and 20 mL rapid air injections. Two different sessions including acute administration of codeine (60 mg) or the placebo were randomly performed., Results: Codeine significantly increased 4-s integrated relaxation pressure (IRP-4s) (P = 0.003) and shortened distal latency (DL) (P = 0.003) of primary peristalsis. The IRP-4s of secondary peristalsis was also significantly higher after codeine than the placebo during air injections with 10 mL (P = 0.048) and 20 mL (P = 0.047). Codeine significantly increased the frequency of secondary peristalsis during air injections with 10 mL than the placebo (P = 0.007), but not for air injection with 20 mL (P = 0.305)., Conclusions: In addition to impair LES relaxation and reduce distal latency of primary peristalsis, codeine impairs LES relaxation of secondary peristalsis and increases secondary peristaltic frequency. Our study supports the notion in human esophagus that the impact of opioids on peristaltic physiology appears to be present in both primary and secondary peristalsis., (© 2021 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Background: The skin microdialysis technique makes it possible to measure histamine release in intact human skin in vivo directly. In this study we have used the microdialysis technique to characterize histamine release by codeine after intracutaneous injections and following skin challenge by a novel atraumatic delivery technique. Objective The purpose of the study was to compare histamine release in human skin by codeine, delivered by an intraprobe drug delivery system (IPD) and intracutancous injections (ICT), with respect to dose-response relations, kinetics of histamine appearance rind decay, correlations between histamine release and skin responses, and reproducibility. Methods: Hollow dialysis fibres were inserted intradermally in 12 healthy subjects. Twelve fibres were inserted in each subject, six fibres in each arm. Each fibre was perfused at a rate of 3 μ/min, and samples were collected in 2 min fractions. By the IPD technique, codeine was administrered to the skin by adding codeine to the perfusion medium. Sequential IPD challenges were performed in one arm, and ICTs were done on the other arm. Results: Sixfold serial dilutions of codeine (0.01–3 mg/mL) caused a significant dose-related histamine release by ICT and IPI). Peak histamine release was found within the first 4 min after skin challenge by ICT and IPD, followed by a fast decline with a dialysate histamine half life of approximalely 2–3 min. Peak histamine release was linearly correlated with cumulative release of the 20min sampling period, and histamine release correlated with weal size. The coefficient of variation on peak histamine release was 18.9% and 4–8% for codeine ICT and IPD, respectively. Conclusion: We have described in detail codeine-induced histamine release in intact human skin in vivo by the microdialysis technique, it was possible to administer codeine atraumatically to the skin by intraprobe delivery. The skin microdialysis technique opens up possibilities for measurement of inflammatory mediators release in normal and diseased skin, and it will be possible to deliver immunopharmacologically active drugs to the skin by intraprobe delivery. [ABSTRACT FROM AUTHOR]

The study aimed to assess the effects of codeine medication on some oxidative stress parameters and how it affects the expression of enolase in neuronal cells. The codeine medication used for the study was Archilin™ with codeine syrup and dihydrocodeine 30 mg. The study used 30 male Wistar rats which were grouped in five: A, B, C, D, and E (n = 6), while treatments were administered for 21 days. Based on the LD 50 s of 6.09 ml/kg body weight (b.wt.) Archilin™ with codeine syrup and 3.145 mg/kg b.wt. dihydrocodeine, group A served as control and were given normal saline; groups B and C were treated with 1 mg/kg and 2 mg/kg b.wt. dihydrocodeine, respectively; while groups D and E were treated with 2 ml/kg and 4 ml/kg b.wt. Archilin™ with codeine syrup, respectively. After treatments, animals were sacrificed via cervical dislocation and the brains were harvested and prepared for determination of oxidative stress biomarkers as well as immunohistochemical studies of neuron-specific enolase (NSE) to assess for neuronal cell integrity. Significantly decreased mean values (p < 0.05) of superoxide dismutase (SOD) and catalase (CAT) activities were observed while malondialdehyde (MDA) is significantly increased (p < 0.05) among treated groups. The expression of enolase was downregulated in treatment groups when compared to control. Animals in group A which are control showed strong staining intensity of the prefrontal cortex compared to groups C, D, and E which showed mild staining. The scoring of group A for cerebellum showed strong staining intensity, groups B and C showed mild staining, while groups D and E showed weak staining intensity. From the findings of this study, prolonged codeine syrup administration causes oxidative stress and this affects the expression of enolase in neuronal cells resulting in glucose hypometabolism which eventually results in functional brain failure., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Chronic opioid use can induce esophageal dysfunction with symptoms resembling achalasia and a manometric pattern of esophagogastric junction-outflow obstruction (EGJ-OO). However, the effect of opioids in acute setting on pharyngeal function and esophageal body contractility has not been investigated., Methods: After positioning the high-resolution impedance manometry (HRiM) catheter, codeine (60 mg) or placebo (glucose syrup) was infused intragastrically. Forty-five minutes post-infusion, participants received liquid, semi-solid, and solid boluses to assess esophageal and pharyngeal function. HRiM analysis was performed adhering to the Chicago classification v3.0. (CC v3.0). Pressure flow analysis (PFA) for the esophageal body and the pharynx was performed using the SwallowGateway™ online platform., Key Results: Nineteen healthy volunteers (HV) [5 male; age 38.3] were included. After codeine administration, higher integrated relaxation pressure 4 s values resulted in significantly reduced deglutitive EGJ relaxation and distal latency was significantly shorter. Distal contractility was similar in both conditions. Bolus flow resistance at the EGJ and distention pressures increased significantly after codeine infusion. Based on CC v3.0, acute infusion of codeine induced EGJ-OO in six HV (p = 0.0003 vs. placebo). Codeine administration induced no significant alterations in any of the pharyngeal PFA metrics., Conclusions & Inferences: In HV, acute administration of codeine increased bolus resistance at the EGJ secondary to induced incomplete EGJ relaxation leading to major motility disorders in a subset of subjects including EGJ-OO. However, an acute single dose of codeine did not affect motility or bolus flow in pharynx and UES. ClinicalTrials.gov number, NCT03784105., (© 2020 John Wiley & Sons Ltd.)

Background & Aims: Enteral nutrition with polymeric intact protein formula is the preferred medical nutrition strategy in critically ill patients when oral intake is insufficient. Enteral nutrition formulas are often rich in casein protein, which has coagulating properties. Coagulation in the stomach impedes gastric emptying and might result in high gastric residual volumes which are a clinical sign of gastrointestinal intolerance and a major reason to decrease or to discontinue enteral feeding. In this study the impact of protein composition of enteral formula on gastric content volume (GCV) during and after continuous feeding was tested in healthy volunteers in whom gastrointestinal conditions of critically ill patients were mimicked., Methods: An enteral formula including 4 proteins (P4) with non-coagulating properties was compared to a casein-dominant formula (Cas) with coagulating properties. Esomeprazole and codeine were administered to mimic stress ulcer prophylaxis and induce gastroduodenal motor dysfunction, both being hallmarks of critically ill patients. GCV was measured with magnetic resonance imaging during and after continuous enteral feeding (100 mL/h for 4h) in a randomized single-center cross-over study. Results are provided as mean (SD). Significance level of p < 0.05 was applied., Results: Twenty subjects completed the study (14 women, 6 men, 25.8 (4.6) years old, BMI: 22.5 (1.5) kg/m 2 ). The GCV as change from baseline at T = 240 (primary endpoint) did not differ between study products (P4: 124.3 (83.4) vs. Cas: 137.1 (102.0) mL, 95% CI: -57.4, 27.0, p = 0.457). During feeding and after cessation of feeding, the area under the GCV-curve (AUC 0-360 GCV) for P4 and Cas was 44631.1 (15546.1) and 52822.2 (19686.1) mL∗min, respectively (p = 0.061). During feeding the GCV was lower at T = 180 min (175.4 (64.8) vs. 205.2 (75.4) mL, p = 0.038) and after cessation of feeding at T = 300 min (81.3 (71.1) vs. 116.3 (84.3) mL, p = 0.004) and T = 330 min (39.9 (53.9) vs. 73.6 (81.1) mL, p = 0.031). With P4 it took less time to reach half of the GCV at T = 240 min compared to Cas (52.8 (27.6) vs. 65.4 (29.9) min, p = 0.020)., Conclusions: In this study in which healthy volunteers received esomeprazole and codeine to mimic gastrointestinal conditions of critically ill patients, observations of secondary endpoints suggest faster gastric emptying with P4 compared to Cas, and less gastric accumulation, possibly due to the non-coagulating properties of the P4 protein blend. Considering the small effect and the possible clinical relevance of reduced intragastric accumulation of enteral nutrition, the potential impact of protein coagulation should be further investigated in relevant study populations. Registered under Netherlands Trial Register identifier no. NTR6423., Competing Interests: Conflict of interest DR, PvH and ZH are employees of Nutricia Research. JT has given scientific advice to AlfaWassermann, Allergan, Christian Hansen, Danone, Janssen, Nutricia, Shire, Takeda, Theravance, Tramedico, Truvion, Tsumura, Zealand and Zeria pharmaceuticals, has received research support from Shire and Tsumura, and has served on the Speaker bureau for Abbott, Allergan, Shire, Takeda, Truvion and Zeria. All other authors declare that there is no conflict of interest regarding the publication of this article., (Copyright © 2021 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

Codeine stimulates skin mast cells and is therefore used in skin tests and as an inducer of experimental itch. MRGPRX2 responds to various drugs, including opioids, to elicit pseudoallergic reactions, but whether it represents the main opiate receptor of skin mast cells remains unknown. By combining a number of approaches, including the silencing of MRGPRX2, we now report that MRGPRX2 is indeed the dominant codeine receptor of dermal mast cells. Activation by codeine displayed profound subject variability and correlated with secretion elicited by compound 48/80 or substance P but not by FcεRI aggregation. Degranulation by codeine was attenuated by stem cell factor, whereas the opposite was found for FcεRI. Compound 48/80 or codeine alone was able to achieve maximum MRGPRX2 activation. MRGPRX2 was rapidly internalized on codeine binding in a β-arrestin-1‒dependent manner. Codeine-triggered β-arrestin activation was also established by the Tango assay. Prestimulation with MRGPRX2 agonists (but not C3a or FcεRI aggregation) resulted in refractoriness to further stimulation by the same or another MRGPRX2 ligand (cross desensitization). This was duplicated in a cell line (RBL-MRGPRX2). Collectively, codeine degranulates skin mast cells through MRGPRX2, at which it acts as a balanced ligand. It has yet to be determined whether codeine-induced refractoriness could be exploited to desensitize MRGPRX2 to prevent severe pseudoallergic reactions., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Paclitaxel use in cancer treatment is limited by a painful syndrome that has no effective treatment. Despite new therapies, drugs of the World Health Organization (WHO) analgesic ladder remain a useful therapeutic tool for cancer pain relief. Since cancer pain is caused by both tumor and chemotherapy, we assessed the efficacy of drugs from the WHO analgesic ladder for cancer pain relief in a paclitaxel-induced pain syndrome (P-IPS) model. P-IPS was induced in rats by one or four injections of paclitaxel on alternate days. The acute and chronic phases were assessed 24 h and 15 days after the first paclitaxel injection, respectively. The mechanical allodynia was evaluated after (step 1 of the ladder) paracetamol, (step 2) codeine alone or plus paracetamol and (step 3) morphine treatment in the acute or chronic phase of P-IPS. Paracetamol, codeine and morphine were equally efficacious in reducing the acute phase of the P-IPS. Codeine plus paracetamol had similar efficacy and potency when administered together in the acute phase of the P-IPS, but produced a longer-lasting effect than when separately managed. Moreover, paracetamol, codeine and morphine partially reduced the chronic phase of P-IPS, losing their efficacy and, in the case of codeine, potency when compared to the acute phase. However, paracetamol plus codeine increased the potency and efficacy of the codeine when compared to codeine administered alone in the chronic phase of P-IPS, producing a long-lasting anti-allodynic effect. Together, analgesics of WHO analgesic ladder reduce both acute and chronic phases of P-IPS, with codeine plus paracetamol presenting more potent, efficacious and long-lasting effect. Thus, in addition to tumor pain, drugs of WHO analgesics ladder could also be useful to treat P-IPS.

Complex structure of cyanobacterium Nostoc sp. exopolysaccharide (EPS), with apparent molecular weight 214 × 10 3  g/mol, can be deduced from its composition. Chemical and NMR analyses found four dominant sugar monomers, namely (1 → 4)-linked α-l-arabinopyranose, β-d-glucopyranose, β-d-xylopyranose and (1 → 3)-linked β-d-mannopyranose, two different uronic acids and a lactyl group, with (1 → 4,6)-linked β-d-glucopyranose as the only branch point suggest a complex structure of this polymer. The dominant uronic acid is α-linked, but it remained unidentified. β-d-Glucuronic acid was present in lower amount. Their position as well as that of lactyl remained undetermined too. Different doses of orally administered EPS in guinea pigs evoked a significant decrease in cough effort and a decrease in airway reactivity. The antitussive efficacy and bronchodilator effect of higher doses of EPS were found to be similar to that of the antitussive drug codeine and the antiasthmatic salbutamol. Without significant cytotoxicity on the RAW 264.7 cells, EPS stimulated the macrophage cells to produce pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and prostaglandins (PGs) and nitric oxide (NO) via induction of COX-2 and iNOS expression, respectively, suggesting that this biopolymer potentiates an early innate immune response and can therefore be used as a new immune modulator., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Several over-the-counter (OTC) drugs are known to be misused. Among them are opioids such as codeine, dihydrocodeine, and loperamide. This work elucidates their pharmacology, interactions, safety profiles, and how pharmacology is being manipulated to misuse these common medications, with the aim to expand on the subject outlined by the authors focusing on abuse prevention and prevalence rates. The reviewed literature was identified in several online databases through searches conducted with phrases created by combining the international non-proprietary names of the drugs with terms related to drug misuse. The results show that OTC opioids are misused as an alternative for illicit narcotics, or prescription-only opioids. The potency of codeine and loperamide is strongly dependent on the individual enzymatic activity of CYP2D6 and CYP3A4, as well as P-glycoprotein function. Codeine can also be utilized as a substrate for clandestine syntheses of more potent drugs of abuse, namely desomorphine ("Krokodil"), and morphine. The dangerous methods used to prepare these substances can result in poisoning from toxic chemicals and impurities originating from the synthesis procedure. OTC opioids are generally safe when consumed in accordance with medical guidelines. However, the intake of supratherapeutic amounts of these substances may reveal surprising traits of common medications.

The present work represents the in vitro (potency, affinity, efficacy) and in vivo (antinociception, constipation) opioid pharmacology of the novel compound 14-methoxycodeine-6- O -sulfate (14-OMeC6SU), compared to the reference compounds codeine-6- O -sulfate (C6SU), codeine and morphine. Based on in vitro tests (mouse and rat vas deferens, receptor binding and [ 35 S]GTPγS activation assays), 14-OMeC6SU has µ-opioid receptor-mediated activity, displaying higher affinity, potency and efficacy than the parent compounds. In rats, 14-OMeC6SU showed stronger antinociceptive effect in the tail-flick assay than codeine and was equipotent to morphine, whereas C6SU was less efficacious after subcutaneous (s.c.) administration. Following intracerebroventricular injection, 14-OMeC6SU was more potent than morphine. In the Complete Freund's Adjuvant-induced inflammatory hyperalgesia, 14-OMeC6SU and C6SU in s.c. doses up to 6.1 and 13.2 µmol/kg, respectively, showed peripheral antihyperalgesic effect, because co-administered naloxone methiodide, a peripherally acting opioid receptor antagonist antagonized the measured antihyperalgesia. In addition, s.c. C6SU showed less pronounced inhibitory effect on the gastrointestinal transit than 14-OMeC6SU, codeine and morphine. This study provides first evidence that 14-OMeC6SU is more effective than codeine or C6SU in vitro and in vivo. Furthermore, despite C6SU peripheral antihyperalgesic effects with less gastrointestinal side effects the superiority of 14-OMeC6SU was obvious throughout the present study.

Objectives: The study aimed to explore the effects of codeine-containing cough syrup (CCS) exposure on cortical morphology and the relationship between cortical characteristics and CCS dependence., Methods: Cortical morphometry based on Computational Anatomy Toolbox (CAT12) was used to compare changes in sulcal depth, gyrification, and cortical thickness of the cerebral cortex from 40 CCS users and 40 healthy controls (HCs) with two-sample t tests (p < 0.05, multiple comparison corrected). Relationships between abnormal cortical morphological changes and the duration of CCS use, impulsivity traits, and age of first use were investigated with correlation analysis (p < 0.05, uncorrected)., Results: CCS users exhibited significantly increased sulcal depth in the bilateral insula, bilateral lingual, bilateral superior frontal, right precuneus, and right middle frontal regions; increased gyrification in the right precentral cortex; and increased cortical thickness in the bilateral precentral, bilateral precuneus, and right superior temporal cortices compared to HCs. In addition, we found significant correlations between the bilateral insula, right superior frontal cortex, and right precentral gyrus and Barratt Impulsiveness Scale (BIS) total scores., Conclusions: Chronic CCS abuse may be associated with aberrant sulcal depth, gyrification, and cortical thickness. These morphological changes might serve as an underlying neurobiological mechanism of impulsive behavior in the CCS users., Key Points: • Cortical morphological changes were detected in CCS users. • Increased sulcal depth, gyrification, and cortical thickness of some regions were found in the CCS users. • Positive correlations between cortical morphological changes and BIS total scores were identified.

Severe and poorly treated pain often accompanies breast cancer. Thus, novel mechanisms involved in breast cancer-induced pain should be investigated. Then, it is necessary to characterize animal models that are reliable with the symptoms and progression of the disease as observed in humans. Explaining cancer-induced nociception in a murine model of breast carcinoma was the aim of this study. 4T1 (10 4 ) lineage cells were inoculated in the right fourth mammary fat pad of female BALB/c mice; after this, mechanical and cold allodynia, or mouse grimace scale (MGS) were observed for 30 days. To determine the presence of bone metastasis, we performed the metastatic clonogenic test and measure calcium serum levels. At 20 days after tumor induction, the antinociceptive effect of analgesics used to relieve pain in cancer patients (acetaminophen, naproxen, codeine or morphine) or a cannabinoid agonist (WIN 55,212-2) was tested. Mice inoculated with 4T1 cells developed mechanical and cold allodynia and increased MGS. Bone metastasis was confirmed using the clonogenic assay, and hypercalcemia was observed 20 days after cells inoculation. All analgesic drugs reduced the mechanical and cold allodynia, while the MGS was decreased only by the administration of naproxen, codeine, or morphine. Also, WIN 55,212-2 improved all nociceptive measures. This pain model could be a reliable form to observe the mechanisms of breast cancer-induced pain or to observe the efficacy of novel analgesic compounds.

Background: Nausea, vomiting, and constipation (OIC) are common adverse effects of acute or chronic opioid use. Naloxegol (25 mg) is an approved peripherally active mu-opiate opioid receptor antagonist., Aim: To compare the effects on pan-gut transit of treatment with codeine, naloxegol, or combination in healthy volunteers., Methods: We conducted a randomized, double-blind, placebo-controlled, single-center, parallel-group study in 72 healthy opioid-naïve adults, randomized to: codeine (30 mg q.i.d.), naloxegol (25 mg daily), codeine and naloxegol, or matching placebo. During 3 days of treatment, we measured gastric emptying (GE) T 1/2 , colonic filling at 6 hours (CF6), colonic geometric center at 24 and 48 hours, and ascending colon emptying (ACE) T 1/2 ., Key Results: Participants were 59.7% women, median BMI 25.0 kg/m 2 , and median age 33.8 years. Codeine significantly retarded GE T 1/2, CF6, overall colonic transit, and ACE T 1/2 . There was significant difference (P = .026) in GE T 1/2 between codeine (144.0 min [IQR 110.5-238.6]) and naloxegol (95.5 min [89.1-135.4]). There was a significant overall group difference in CF6 (P = .023), with significant difference (P = .019) between codeine (11.0% [0.0-45.0]) and naloxegol (51% [18.8-76.2]). However, no significant differences were found between codeine-treated participants concomitantly receiving placebo or naloxegol., Conclusions and Inferences: Short-term administration of naloxegol (25 mg) in healthy, opioid-naïve volunteers does not reverse the retardation of gastric, small bowel, or colonic transit induced by acute administration of codeine. Further studies with naloxegol at higher dose are warranted to assess the ability to reverse the retardation of transit caused by acute administration of codeine in opioid-naïve subjects., (© 2018 John Wiley & Sons Ltd.)

Unexplained chronic cough (UCC) affects millions of patients worldwide. New therapeutic approaches to this condition are urgently needed, since current treatment options provide only symptomatic relief. Cough reflex hypersensitivity has been shown to play an important role in the pathogenesis of UCC. The transient receptor potential vanilloid type 1 (TRPV1) is present on peripheral terminals of airway sensory nerves and modulation of its activity represents a potential target for the pharmacological treatment of UCC. The aim of this study was to explore the efficacy and the possible mechanism of SB705498, a TRPV1 antagonist, for cough in a capsaicin-induced cough animal model (i.e. guinea pigs). Induction of cough by capsaicin was successfully implemented in the guinea pigs, and the animals that met the inclusion criteria were randomly divided into four treatment groups: (1) Saline inhalation group (NSInh group, N = 10, negative control group), (2) Codeine phosphate intraperitoneal injection group (CPInp group, N = 10, positive control group), (3) SB705498 inhalation group (SBInh group, N = 10), (4) SB705498 intragastric administration group (SBIng group, N = 10). After treatment with above compounds, the capsaicin-induced cough experiment was performed again. The cough numbers and the cough incubation periods were recorded to evaluate the antitussive effect of SB705498. Enzyme-linked immunosorbent assay (ELISA) testing and Immunohistochemistry (IHC) staining for substance P (SP), calcitonin gene related peptide (CGRP) and neurokinin A (NKA) expression in lung and brain tissues were performed as an indication of neurogenic inflammation. Hematoxylin-Eosin (H&E) staining was used to observe the pathology morphology of lung and brain tissues. When the CPInp, SBInh and SBIng groups were compared to the NSInh group, the cough numbers were significantly reduced (p < .001), while the cough incubation periods were significantly prolonged (P < .001). In addition, the expression of SP, CGRP and NKA in lung and brain tissue was reduced (P < .05). None of the animals in the four groups exhibited lung and brain parenchymal inflammation. The results from this study showed that SB705498 had a significant antitussive effect, could reduce the neurogenic inflammation by reducing the expression of SP, CGRP and NKA in a capsaicin-induced cough model of guinea pigs. The results further indicated that TRPV1 played an important role in UCC and SB705498 might be a promising therapeutic agent for UCC., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Bleaching-induced tooth sensitivity (TS) is highly prevalent., Objective: This study aimed to determine if the combination of opioids and nonopioids analgesics (Tylex) may provide a better analgesic effect., Method: A triple-blind, parallel, randomized two-center clinical trial was conducted with 105 healthy patients who received either a placebo or a combination of acetaminophen/codeine. The first dose of Tylex 30 mg (acetaminophen 500 mg/codeine 30 mg) or placebo was administered one hour before the in-office bleaching (35% hydrogen peroxide), and extra doses were administered every six hours for 48 hours. The TS was recorded using a visual analog scale of 0 to 10 and a numeric rating scale of 0 to 4 in different periods: during bleaching, one hour up to 24 hours, and 24 hours up to 48 hours postbleaching. The color was measured before and one month after dental bleaching with a visual shade guide (Vita Classical), Vita Bleachedguide 3D-MASTER, and the spectrophotometer Vita Easyshade. The absolute risk of TS was evaluated using the Fisher exact test. Data of TS intensity with numeric rating scale of the two groups were compared with the Mann-Whitney U-test and the Friedman test, while data from the visual analog scale were evaluated by two-way repeated measures analysis of variance and the Tukey test for pairwise comparison. The color changes between groups were compared using the Student t-test (α=0.05)., Results: No significant differences between the groups were observed in the risk and intensity of TS. The overall absolute risk of TS was approximately 96%. No significant differences between groups were observed in terms of color change ( p>0.05) for any scale., Conclusion: The use of an acetaminophen/codeine combination prior to in-office bleaching does not reduce the risk and intensity of bleaching-induced TS.

Black older adults often experience disparities in pain treatment that results in unmet pain needs. The aims of this study were to assess the pain management experiences of a group of community dwelling Black older adults and identify gaps in clinical practice. A qualitative, descriptive design was employed using the methodology of ethnography. The setting was an urban, low-income, community elderly housing high-rise facility. Participants included facility residents (n = 106); of these, 20 completed structured qualitative interviews. The Brief Pain Inventory and qualitative interviews were used to determine pain prevalence, treatment practices, and barriers. Eighty-six percent of the participants had severe pain with a mean worst pain rating of 7 on a 0 to 10 scale. Pain interfered moderately with general activity (5.59), walking (5.73) and normal work (5.70), also measured on 0 to 10 scales. Participants preferred non-opioid analgesics, topical over-the-counter treatments, and nonpharmacological interventions such as prayer/meditation, and exercise for treatment. Medications most commonly used by participants for pain management included, hydrocodone with acetaminophen (28.6%), nonsteroidal anti-inflammatory drugs (13.2%), acetaminophen with codeine (12%), and tramadol (9.9). Qualitative interviews revealed that pain management barriers were centered around communication concerns about side effects, fears of addiction, and provider mistrust. A communication gap exists between patients and providers. Discussing patient treatment preferences, providing balanced treatment information, and following-up with patients on treatment plan effectiveness by phone can improve how pain is managed for Black older adults., (Copyright © 2017 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.)

Context: Codeine, also known as 3-methylmorphine, is an opiate used to treat pain, as a cough medicine and for diarrhoea. No study on the effects of codeine on the metabolic capacity of CYP enzyme is reported., Objective: In order to investigate the effects of codeine on the metabolic capacity of cytochrome P450 (CYP) enzymes, a cocktail method was employed to evaluate the activities of CYP2B1, CYP2D1, CYP1A2, CYP3A2 and CYP2C11., Materials and Methods: Sprague-Dawley rats were randomly divided into codeine group (low, medium, high) and control group. The codeine group rats were given 4, 8, 16 mg/kg (low, medium, high) codeine by continuous intragastric administration for 14 days. Five probe drugs bupropion, metroprolol, phenacetin, midazolam and tolbutamide were given to rats through intragastric administration, and the plasma concentrations were determined by UPLC-MS/MS., Results and Conclusion: The pharmacokinetic parameters of bupropion and metroprolol experienced obvious change with AUC (0-t) , C max increased and CL decreased for bupropion in medium dosage group and midazolam low dosage group. This result indicates that the 14 day-intragastric administration of codeine may inhibit the metabolism of bupropion (CYP2B1) and midazolam (CYP3A2) in rat. Additional, there are no statistical differences for albumin (ALB), alkaline phosphatase (ALP), creatinine (Cr) after 14 intragastric administration of codeine, while alanine aminotransferase (ALT), aspartate aminotransferase (AST), uric acid (UA) increased compared to control group. The biomedical test results show continuous 14 day-intragastric administration of codeine would cause liver damage.

Repeated opioid administration produces analgesic tolerance, which may lead to dose escalation. Brain CYP2D metabolizes codeine to morphine, a bioactivation step required for codeine analgesia. Higher brain, but not liver, CYP2D is found in smokers and nicotine induces rat brain, but not liver, CYP2D expression and activity. Nicotine induction of rat brain CYP2D increases acute codeine conversion to morphine, and analgesia, however the role of brain CYP2D on the effects of repeated codeine exposure and tolerance is unknown. Rats were pretreated with nicotine (brain CYP2D inducer; 1mg/kg subcutaneously) or vehicle (saline; 1ml/kg subcutaneously). Codeine (40-60mg/kg oral-gavage) or morphine (20-30mg/kg oral-gavage) was administered daily and analgesia was assessed daily using the tail-flick reflex assay. Nicotine (versus saline) pretreatment increased acute codeine analgesia (1.32-fold change in AUC 0-60 min ; p<0.05) and the rate of loss of peak analgesia (11.42%/day versus 4.20%; p<0.006) across the first four days of codeine administration (time to negligible analgesia). Inducing brain CYP2D with nicotine did not alter acute morphine analgesia (1.03-fold; p>0.8), or the rate of morphine tolerance (8.1%/day versus 7.6%; p>0.9). The rate of both codeine and morphine tolerance (loss in peak analgesia from day 1 to day 4) correlated with initial analgesic response on day 1 (R=0.97, p<001). Increasing brain CYP2D altered initial analgesia and subsequent rate of tolerance. Variation in an individual's initial response to analgesic (e.g. high initial dose, smoking) may affect the rate of tolerance, and thereby the risk for dose escalation and/or opioid dependence., (Copyright © 2017 Elsevier Inc. All rights reserved.)

14-O-methyl (14-O-Me) group in morphine-6-O-sulfate (M6SU) or oxymorphone has been reported to be essential for enhanced affinity, potency and antinociceptive effect of these opioids. Herein we report on the pharmacological properties (potency, affinity and efficacy) of the new compound, 14-O-methylmorphine (14-O-MeM) in in vitro. Additionally, we also investigated the antinociceptive effect of the novel compound, as well as its inhibitory action on gastrointestinal transit in in vivo. The potency and efficacy of test compound were measured by [ 35 S]GTPγS binding, isolated mouse vas deferens (MVD) and rat vas deferens (RVD) assays. The affinity of 14-O-MeM for opioid receptors was assessed by radioligand binding and MVD assays. The antinociceptive and gastrointestinal effects of the novel compound were evaluated in the rat tail-flick test and charcoal meal test, respectively. Morphine, DAMGO, Ile 5,6 deltorphin II, deltorphin II and U-69593 were used as reference compounds. 14-O-MeM showed higher efficacy (E max ) and potency (EC 50 ) than morphine in MVD, RVD or [ 35 S]GTPγS binding. In addition, 14-O-MeM compared to morphine showed higher affinity for μ-opioid receptor (MOR). In vivo, in rat tail-flick test 14-O-MeM proved to be stronger antinociceptive agent than morphine after peripheral or central administration. Additionally, both compounds inhibited the gastrointestinal peristalsis. However, when the antinociceptive and antitransit doses for each test compound are compared, 14-O-MeM proved to have slightly more favorable pharmacological profile. Our results affirm that 14-O-MeM, an opioid of high efficacy and affinity for MOR can be considered as a novel analgesic agent of potential clinical value., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Purpose of Review: Use of perioperative opioids for surgical pain management of children presents clinical challenges because of concerns of serious adverse effects including life-threatening respiratory depression. This is especially true for children with history of obstructive sleep apnea. This review will explore current knowledge of clinically relevant factors and genetic polymorphisms that affect opioid metabolism and postoperative outcomes in children., Recent Findings: Within the past several years, an increasing number of case reports have illustrated clinically important respiratory depression, anoxic brain injuries and even death among children receiving appropriate weight-based dosages of codeine and other opioids for analgesia at home setting particularly following tonsillectomy. Several national and international organizations have issued advisories on use of codeine in pediatrics, based on cytochrome P450 family 2 subfamily D type 6 (CYP2D6) pharmacogenetics. We have discussed the pros and cons of alternatives to codeine for pain management., Summary: Although routine preoperative genotyping to identify children at risk and personalized opioid use for pediatric perioperative pain management is still a distant reality, current known implications of CYP2D6 pharmacogenetics on codeine use shows that pharmacogenetics has the potential to guide anesthesia providers on perioperative opioid selection and dosing to maximize efficacy and safety.

Background: Cough is produced by the same neuronal pool implicated in respiratory rhythm generation, and antitussive drugs acting at the central level, such as opioids, may depress ventilation. Levodropropizine is classified as a nonopioid peripherally acting antitussive drug that acts at the level of airway sensory nerves. However, the lack of a central action by levodropropizine remains to be fully established. We set out to compare the effects of levodropropizine and the opioid antitussive agent dihydrocodeine on the respiratory responses to a conventional CO 2 rebreathing test in patients with chronic cough of any origin., Methods: Twenty-four outpatients (aged 39-70 years) with chronic cough were studied. On separate runs, each patient was randomly administered 60 mg levodropropizine, 15 mg dihydrocodeine, or a matching placebo. Subsequently, patients breathed a mixture of 93% oxygen and 7% CO 2 for 5 min. Fractional end-tidal CO 2 (Fetco 2 ) and inspiratory minute ventilation (V˙i) were continuously monitored. Changes in breathing pattern variables were also assessed., Results: At variance with dihydrocodeine, levodropropizine and placebo did not affect respiratory responses to hypercapnia (P < .01). The ventilatory increases by hypercapnia were mainly accounted for by a rise in the volume components of the breathing pattern., Conclusions: The results are consistent with a peripheral action by levodropropizine; the assessment of ventilatory responses to CO 2 may represent a useful tool to investigate the central respiratory effects of antitussive agents., Trial Registry: European Union Clinical Trials Register (EudraCT No.: 2013-004735-68); URL: https://www.clinicaltrialsregister.eu/., (Copyright © 2017. Published by Elsevier Inc.)

Background: "Krokodil" or "Crocodile" is an illegal homemade desomorphine drug obtained from chemical reactions of commercial codeine drugs with several other powerful and highly toxic chemical agents increasing its addiction and hallucinogenic effects when compared with other morphine analogues., Methods: This paper summarizes a complete review about an old drug called desomorphine (Krokodil), presenting its chemistry, pharmacology, metabolism, toxicology and analysis., Results: It is of particular interest and concern because this cheaper injectable semisynthetic opioid drug has been largely used in recent years for recreational purposes in several Eastern European as well as North and South American countries, despite known damage to health that continuous use might induce. These injuries are much stronger and more aggressive than morphine's, infecting and rotting skin and soft tissue to the bone of addicts at the point of injection in less than three years, which, in most cases, evolves to death. On this basis, it is imperative that literature reviews focus on the chemistry, pharmacology, toxicology and analysis of dangerous Krokodil to find strategies for rapid and effective determination to mitigate its adverse effects on addicts and prevent consumption., Conclusions: It is crucial to know the symptoms and consequences of the use of Krokodil, as well as METHODS: for identification and quantification of desomorphine, contaminants and metabolites, which can help the forensic work of diagnosis and propose actions to control and eradicate this great danger to public health around the world., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Angiogenesis is an important characteristic of cancer. Switching from the avascular phase to the vascular phase is a necessary process for tumor growth. Therefore, research in cancer treatment has focused on angiogenesis as a drug target. Despite the widespread use of opioids to treat pain in patients with cancer, little is known about the effect of these drugs on vascular endothelium and angiogenesis., Objectives: We aimed to investigate the efficacies of morphine, codeine, and tramadol in 3 different concentrations on angiogenesis in hens' eggs., Study Design: This is a prospective, observational, controlled, in-vivo animal study., Setting: Single academic medical center., Methods: This study was conducted on the chorioallantoic membrane (CAM) of fertilized hens' eggs. The efficacies of morphine, codeine, and tramadol in 3 different concentrations were evaluated on angiogenesis in a total of 165 hens' eggs., Results: Statistically significant differences were found between drug-free agarose used as a negative control and concentrations of morphine of 10 µM and 1 µM, a concentration of tramadol of 10 µM, and concentrations of codeine of 10 µM and 1 µM. Concentrations of morphine of 10 µM and 1 µM showed strong antiangiogenic effects. While codeine had strong antiangiogenic effects at high concentrations, at 0.1 µM it was shown to have weak antiangiogenic effects. However, tramadol at a concentration of 10 µM had only weak antiangiogenic effects., Limitations: This is just a CAM model study., Conclusion: In this study, we tested the effects of 3 different opioid drugs on angiogenesis in 3 different concentrations, and we observed that morphine was a good anti-angiogenic agent, but tramadol and codeine only had anti-angiogenic effects at high doses.Key Words: Morphine, codeine, tramadol, opioid, bevacizumab, chorioallantoic membrane (CAM), angiogenesis.

Codeine is a widely used analgesic, that is available for sale in pharmacies over the counter (OTC) in a number of countries including the UK, South Africa, Ireland, France and Australia. In these countries with OTC codeine sales there has been emerging concerns about misuse of and dependence on codeine containing combination analgesics, with increasing numbers of people presenting for help with codeine dependence at primary care and addiction treatment services. This has led to many countries reviewing availability of codeine in OTC available preparations, and considering possible measures to reduce harms from misuse of OTC codeine containing combination analgesics.

Codeine has been prescribed to pediatric patients for many decades as both an analgesic and an antitussive agent. Codeine is a prodrug with little inherent pharmacologic activity and must be metabolized in the liver into morphine, which is responsible for codeine's analgesic effects. However, there is substantial genetic variability in the activity of the responsible hepatic enzyme, CYP2D6, and, as a consequence, individual patient response to codeine varies from no effect to high sensitivity. Drug surveillance has documented the occurrence of unanticipated respiratory depression and death after receiving codeine in children, many of whom have been shown to be ultrarapid metabolizers. Patients with documented or suspected obstructive sleep apnea appear to be at particular risk because of opioid sensitivity, compounding the danger among rapid metabolizers in this group. Recently, various organizations and regulatory bodies, including the World Health Organization, the US Food and Drug Administration, and the European Medicines Agency, have promulgated stern warnings regarding the occurrence of adverse effects of codeine in children. These and other groups have or are considering a declaration of a contraindication for the use of codeine for children as either an analgesic or an antitussive. Additional clinical research must extend the understanding of the risks and benefits of both opioid and nonopioid alternatives for orally administered, effective agents for acute and chronic pain., (Copyright © 2016 by the American Academy of Pediatrics.)

The purpose of this study was to determine the pharmacokinetic and antinociceptive effects of an acetaminophen/codeine combination administered orally to six healthy greyhounds. Antinociception was assessed using an electronic von Frey (vF) device as a mechanical/pressure model. Acetaminophen was administered at a dose of 600 mg (14.4-23.1 mg/kg) and codeine phosphate at 90 mg (2.1-3.3 mg/kg) equivalent to 67.5 mg codeine base (1.6-2.5 mg/kg). The geometric mean maximum plasma concentrations of acetaminophen, codeine, and codeine-6-glucuronide were 7.95 μg/mL, 11.0 ng/mL, and 3819 ng/mL, respectively. Morphine concentrations were <1 ng/mL. The terminal half-lives of acetaminophen, codeine, and codeine-6-glucuronide were 0.94, 1.71, and 3.12 h. There were no significant changes in vF thresholds, except at 12 h which decreased on average by 17% compared to baseline. The decrease in vF thresholds at 12 h could be due to aversion, hyperalgesia, or random variability. The lack of antinociception in this study could be due to a true lack of antinociception, lack of model sensitivity, or specificity. Further studies using different models (including clinical trials), different dog breeds, multiple dose regimens, and a range of dosages are needed prior to recommended use or concluding lack of efficacy for oral acetaminophen/codeine in dogs., (© 2016 John Wiley & Sons Ltd.)

The aim of this study was to examine the risk of early discontinuation of metformin as a proxy for intolerance, associated with use of drugs known to inhibit transporters involved in metformin distribution. We analysed all incident users of metformin in Denmark between 2000 and 2012 (n = 132,221) and in a cohort of US patients (n = 296,903). Risk of early discontinuation of metformin was assessed using adjusted logistic regression for 28 drugs putatively inhibiting metformin transporters and four negative controls. Increased odds ratio of early discontinuation of metformin was only associated with codeine, an inhibitor of organic cation transporter 1 in both cohorts [adjusted odds ratio (OR) in Danish cohort (95% CI): 1.13 (1.02-1.26), adjusted OR in American cohort (95% CI): 1.32 (1.19-1.47)]. The remaining drugs were not associated with increased odds ratio of early discontinuation and, surprisingly, four drugs were associated with a decreased risk. These findings indicate that codeine use may be associated with risk of early discontinuation of metformin and could be used as a basis for further investigation., (© 2016 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).)

Codeine is a drug that until recently was widely used in children. It was endorsed by the WHO as the second step on the analgesic ladder for cancer pain and has been used routinely for postoperative and breakthrough pain. Recently, its safety and efficacy have been called into question, following deaths after adenotonsillectomy was associated with its use. This has led to regulation by the US Food and Drug Administration, European Medicines Agency and the UK Medicines and Healthcare products Regulatory Agency to place significant restrictions on its use, and some centres have stopped using it altogether.In this article, we discuss the developmental pharmacology underpinning its action, reviewing what is known about the pharmacokinetics, pharmacodynamics and pharmacogenetics in children, how this relates to prescribing, as well as the practical issues and the recent regulatory framework surrounding its use., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

The therapeutic use of opioids is limited by the development of tolerance to the analgesic effect and the cellular and molecular mechanisms underlying this phenomenon are still not completely understood. For this reason the search for new analgesic derivatives, endowed with lower tolerance, is always an active field. The newly synthesized 14-O-Methylmorphine-6-sulfate (14-O-MeM6SU) shows high efficacy in in vitro assays and a strong analgesic action in the rat tail flick test. The aim of present work was to investigate: the analgesic effect of 14-O-MeM6SU in mouse tail-flick test; the tolerance to analgesic effect of 14-O-MeM6SU compared to morphine in mice, the effects of test compounds on glutamatergic neurotransmission by measuring spontaneous excitatory postsynaptic currents (sEPSCs) of layer V pyramidal cells from rat prefrontal cortices; and the effect of acute and chronic 14-O-MeM6SU treatments on opioid receptor gene expression in SH-SY5Y neuroblastoma cells expressing μ-opioid (MOP) and nociceptin/opioid receptor-like 1 (NOP) receptors. 14-O-MeM6SU was 17 times more potent than morphine in analgesia and had long duration of action in analgesic dose equipotent to morphine. Mice were treated subcutaneously (s.c.) either with 200 μmol/kg morphine or with 14-O-MeM6SU (12 μmol/kg) twice daily for three days. The magnitude of tolerance or cross-tolerance indicated by the shift in antinociceptive ED50 measured was greater for morphine compared to 14-O-MeM6SU. Subsequent to behavioral testing, patch-clamp experiments in layer V pyramidal neurons of rat prefrontal cortical slices in the presence of bicuculline were performed. Both 14-O-MeM6SU (0.1 μM) and morphine (1 μM) decreased the frequency of sEPSCs, indicating reduction of glutamate release. The effect of the novel compound was reversed by the opioid receptor antagonist naloxone, indicating an opioid mediated action. In contrast, the amplitude was not affected. Finally, gene expression data showed a dose dependent down-regulation of MOP receptor after 24h and 48 h exposure to 14-O-MeM6SU. Interestingly, no changes were detected for NOP receptor gene expression. The specific lack of this effect could be related to the lower tolerance development to analgesic effect of 14-O-MeM6SU. Furthermore, 14-O-MeM6SU displayed high intrinsic efficacy possibly an important factor in the observed effects. Further, the observed inhibition of glutamatergic signaling might be attributed also to the reduction of opioid tolerance. Based on our results the development of a new clinically important, safe analgesic agent might be possible., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Echinacea purpurea has a long history in traditional medicine. To verify the pharmacological efficacy of active principles, a polysaccharide-phenolic-protein complex has been isolated from flowering parts of herb by alkaline extraction. It showed on GPC and HPLC one peak of molecular mass around 10 kDa. Chemical and spectroscopic analyses revealed carbohydrate, phenolic and protein contents in Echinacea complex. Pharmacological tests have shown its marked cough suppressing and bronchodilatory effects. The antitussive effect of Echinacea was similar to the narcotic drug codeine and the bronchodilatory effect was more significant than salbutamol, the antiasthmatic drug used in a clinical practice. Pharmacodynamic study shows the beneficial effects of Echinacea complex on the respiratory system and highlights the great potential for development of antitussive and bronchodilatory drugs from natural sources., (Copyright © 2015 Elsevier B.V. All rights reserved.)

CYP2D metabolically activates codeine to morphine, which is required for codeine analgesia. Permeability across the blood-brain barrier, and active efflux, suggests that initial morphine in the brain after codeine is due to brain CYP2D metabolism. Human CYP2D is higher in the brains, but not in the livers, of smokers and 7-day nicotine treatment induces rat brain, but not hepatic, CYP2D. The role of nicotine-induced rat brain CYP2D in the central metabolic activation of peripherally administered codeine and resulting analgesia was investigated. Rats received 7-day nicotine (1 mg/kg subcutaneously) and/or a single propranolol (CYP2D mechanism-based inhibitor; 20 μg intracerebroventricularly) pretreatment, and then were tested for analgesia and drug levels following codeine (20 mg/kg intraperitoneally) or morphine (3.5 mg/kg intraperitoneally), matched for peak analgesia. Nicotine increased codeine analgesia (1.59X AUC(0-30 min) vs vehicle; p<0.001), while propranolol decreased analgesia (0.56X; p<0.05); co-pretreatment was similar to vehicle controls (1.23X; p>0.1). Nicotine increased, while propranolol decreased, brain, but not plasma, morphine levels, and analgesia correlated with brain (p<0.02), but not plasma (p>0.4), morphine levels after codeine. Pretreatments did not alter baseline or morphine analgesia. Here we show that brain CYP2D alters drug response despite the presence of substantial first-pass metabolism of codeine and further that nicotine induction of brain CYP2D increases codeine response in vivo. Thus variation in brain CYP2D activity, due to genetics or environment, may contribute to individual differences in response to centrally acting substrates. Exposure to nicotine may increase central drug metabolism, not detected peripherally, contributing to altered drug efficacy, onset time, and/or abuse liability.

Krokodil (also known as crocodile, croc, krok, and poor man's heroin) is a suspension of desomorphine as the core substance with contaminants like iodide, phosphorous, and heavy metals, which are the byproducts of the manufacturing process. The name krokodil emerged due to the appearance of the skin lesions around the injection site, where it turns green and scaly like a crocodile skin due to desquamation. It is also known as the "drug that eats junkies" and "Russia's Designer drug." It is not available as a prescription anywhere in the world. It is a modern day man-made Frankenstein-like drug, which was manufactured due to the pursuit of drug addicts to make a cheap yet effective narcotic but ended up in creating havoc on its users. It has devastating effects on its users, including damage to skin, blood vessels, muscles, bones, and sometimes even multiorgan failure and eventually death. A systemic review was conducted to obtain any available data for the term krokodil to collect information for this article.

Objective: The use of herbal medicinal products in the management of pain has been increasing steadily in recent years, often in combination with conventional analgesics, which can induce significant interactions. In traditional medicine, rosemary was used as mild analgesic, for relieving renal colic pain and dysmenorrhea. The aim of our study was to examine analgesic effects of rosemary essential oil and its pharmacodynamic interactions with codeine and paracetamol in mice., Materials and Methods: The identification and quantification of chemical constituents of the essential oil isolated from air-dried aerial parts of rosemary were carried out by GC/FID and GC/MS. The hot plate test was performed on NMRI mice by placing them individually on hot plate and assessing their response to the thermal stimulus., Results: In this research, we identified 29 chemical compounds of the studied rosemary essential oil, and the main constituents were 1,8-cineole, camphor, and α-pinene. Administration of investigated essential oil increased significantly the latency time of animal response to heat-induced pain between 20th and 50th minute of the test, when compared to saline-treated group. Rosemary essential oil in the dose of 20 mg/kg was shown to be more efficient than in the dose of 10 mg/kg, in combinations with both codeine and paracetamol., Conclusions: Our findings support the use of rosemary in the management of pain and indicate a therapeutic potential of rosemary essential oil in combination with analgesic drugs. The mechanisms involved in analgesic effects of rosemary essential oil and the potential influence on cytochromes and drug metabolism should be more in-depth investigated.

Acute and chronic pain often requires a multimodal approach. Combination therapy reduces the number of individual daily administrations and improves patient's compliance with the prescribed analgesic treatment. Despite the association codeine/paracetamol is one of the most widely used central analgesic, the exact mechanism of action, particularly of paracetamol, is still object of pharmacological research. Recent findings showed that paracetamol may act through cerebral cyclo-oxygenase, descending opioidergic inhibitory pathways, serotonin pathway, and the endocannabinoid system; while codeine activity seems to related not only to its conversion to morphine, as previously known, but also by itself and through its metabolites, such as norcodeine (NORC) and codeine-6-glucuronide (C-6-G). The addition of codeine to paracetamol significantly improves the analgesic action and reduces the number needed to treat (NNT) from 5 to 2.3-3.1. Recent warnings about the risk of its metabolism related to CYP450 and its genetic variability in general population should be mainly considered when the association is used in paediatric patients undergoing tonsillectomy and/or adenoidectomy procedures for obstructive sleep apnoea syndrome (OSAS). In adults, the association codeine/paracetamol has been shown to be effective and safe in different settings: acute pain, trauma patients, and chronic nociceptive pain.

Arabinogalactan is a polysaccharide isolated from the roots of the medicinal plant Withania somnifera L. It contains 65% arabinose and 18% galactose. The aim of the present study was to evaluate the antitussive activity of arabinogalactan in conscious, healthy adult guinea pigs and the role of the opioid pathway in the antitussive action. A polysaccharide extract was given orally in a dose of 50 mg/kg. Cough was induced by an aerosol of citric acid in a concentration 0.3 mol/L, generated by a jet nebulizer into a plethysmographic chamber. The intensity of cough response was defined as the number of cough efforts counted during a 3-min exposure to the aerosol. The major finding was that arabinogalactan clearly suppressed the cough reflex; the suppression was comparable with that of codeine that was taken as a reference drug. The involvement of the opioid system was tested with the use of a blood-brain barrier penetrable, naloxone hydrochloride, and non-penetrable, naloxone methiodide, to distinguish between the central and peripheral mu-opioid receptor pathways. Both opioid antagonists acted to reverse the arabinogalactan-induced cough suppression; the reversion was total over time with the latter antagonist. We failed to confirm the presence of a bronchodilating effect of the polysaccharide, which could be involved in its antitussive action. We conclude that the polysaccharide arabinogalactan from Withania somnifera has a distinct antitussive activity consisting of cough suppression and that this action involves the mu-opioid receptor pathways.

Chronic morphine therapy has been associated with paradoxically increased pain. Codeine is a widely used opioid, which is metabolized to morphine to elicit analgesia. Prolonged morphine exposure exacerbates pain by activating the innate immune toll-like receptor-4 (TLR4) in the central nervous system. In silico docking simulations indicate codeine also docks to MD2, an accessory protein for TLR4, suggesting potential to induce TLR4-dependent pain facilitation. We hypothesized codeine would cause TLR4-dependent hyperalgesia/allodynia that is disparate from its opioid receptor-dependent analgesic rank potency. Hyperalgesia and allodynia were assessed using hotplate and von Frey tests at days 0, 3 and 5 in mice receiving intraperitoneal equimolar codeine (21 mg kg(-1)), morphine (20 mg kg(-1)) or saline, twice daily. This experiment was repeated in animals with prior partial nerve injury and in TLR4 null mutant mice. Interventions with interleukin-1 receptor antagonist (IL-1RA) and glial-attenuating drug ibudilast were assessed. Analyses of glial activation markers (glial fibrillary acid protein and CD11b) in neuronal tissue were conducted at the completion of behavioural testing. Despite providing less acute analgesia (P=0.006), codeine induced similar hotplate hyperalgesia to equimolar morphine vs saline (-9.5 s, P<0.01 and -7.3 s, P<0.01, respectively), suggesting codeine does not rely upon conversion to morphine to increase pain sensitivity. This highlights the potential non-opioid receptor-dependent nature of codeine-enhanced pain sensitivity-although the involvement of other codeine metabolites cannot be ruled out. IL-1RA reversed codeine-induced hyperalgesia (P<0.001) and allodynia (P<0.001), and TLR4 knock-out protected against codeine-induced changes in pain sensitivity. Glial attenuation with ibudilast reversed codeine-induced allodynia (P<0.001), and thus could be investigated further as potential treatment for codeine-induced pain enhancement.

Purpose: We present a database of prescription drugs and international normalized ratio (INR) data and the applied methodology for its use to assess drug-drug interactions with vitamin K antagonists (VKAs). We use the putative interaction between VKAs and tramadol as a case study., Methods: We used a self-controlled case series to estimate the incidence rate ratio (IRR) comparing the rate of INR measurements of ≥4.0 in concomitant tramadol and VKA-exposed periods to VKA-only-exposed periods. Secondary analyses considered specific subgroups, alternative exposure criteria, alternative outcome definitions, and other drugs., Results: We identified 513 VKA users with at least 1 INR measurement ≥4.0 and concomitant tramadol and VKA exposure during the observation period. The overall IRR was 1.80 (95% confidence interval [CI], 1.53-2.10), with a stronger association among users of phenprocoumon compared to warfarin (IRR, 3.37; 95%CI, 2.50-4.53 and IRR, 1.46; 95%CI, 1.20-1.76, respectively). We observed larger IRRs with stricter outcome definitions. Concomitant tramadol and VKA exposure was also associated with an increased rate of low INR measurements (i.e., <1.5; IRR, 1.70; 95%CI, 1.37-2.13). Morphine and, to some extent, oxycodone, penicillin, beta-blockers, and inhaled beta-agonists were associated with high INR., Conclusions: The approach successfully identified an interaction between tramadol and VKA. However, associations observed for other drugs with no known VKA interaction suggest that the current approach may have too low specificity to be useful as a screening tool, at least for drugs for which time-varying confounding may be present., (Copyright © 2014 John Wiley & Sons, Ltd.)

Ethnopharmacological Relevance: Solanum virginianum L. is used for the management of fever, bronchial asthma and cough for thousands of years. While the link to a particular indication has been established in human, the active principle of the formulation remains unknown. Herein, we have investigated a polysaccharide isolated from its leaves., Materials and Methods: Utilizing traditional aqueous extraction protocol and using chemical, chromatographic, spectroscopic and biological methods we have analysed an antitussive pectic arabinogalactan isolated from its leaves., Results: The water extracted polymer (WEP) is a highly branched arabinogalactan containing, inter alia, (1,3)-, (1,6)- and (1,3,6)-linked β-Galp residues, terminal-, (1,5)- and (1,3,5)-linked units of α-Araf together with (1,2)- and (1,2,4)-linked Rhap. In vivo investigation on the citric-acid induced cough efforts in guinea pigs shows that the antitussive activity of the orally administered pectic arabinogalactan is greater than codeine phosphate. Remarkably, this macromolecule neither altered specific airway smooth muscle reactivity significantly nor it induced considerable change on levels of NO in expiratory flow in guinea pigs., Conclusions: Thus, traditional aqueous extraction method provides a molecular entity, which induces antitussive activity without addiction: this could represent an attractive approach in phytotherapeutic management., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Clinicians and patients continue to convey interest in personalized medicine. The objective of personalized medicine is to improve healthcare by tailoring disease prevention, diagnosis, and treatment strategies for individuals based on their unique clinical history and genetic composition. This article offers an overview of pharmacogenomics, discusses caveats specific to pharmacogenomics in pediatric populations, provides evidence-based recommendations for pediatric clinicians, and offers insight regarding the future role of pharmacogenomics testing in pediatric medicine. Reviews of the current literature and thoughtful discussions are presented regarding the pharmacogenomics of antidepressants, codeine and oncologic, asthma, and immunomodulatory pharmacotherapies., (© The Author(s) 2014.)

The vast range of genetic diversity contributes to a wonderful array of human traits and characteristics. Unfortunately, a consequence of this genetic diversity is large variability in drug response between people, meaning that no single medication is safe and effective in everyone. The debilitating and sometimes deadly consequences of adverse drug reactions (ADRs) are a major and unmet problem of modern medicine. Pharmacogenomics can uncover associations between genetic variation and drug safety and has the potential to predict ADRs in individual patients. Here we review pharmacogenomic successes leading to changes in clinical practice, as well as clinical areas probably to be impacted by pharmacogenomics in the near future. We also discuss some of the challenges, and potential solutions, that remain for the implementation of pharmacogenomic testing into clinical practice for the significant improvement of drug safety., (© 2014 The Authors. Clinical Genetics published by JohnWiley & Sons A/S. Published by JohnWiley & Sons Ltd.)

Human plasma contains wide variety of bioactive proteins that have proved essential in therapeutic discovery. However many human plasma proteins remain orphans with unknown biological functions. Evidences suggest that some plasma components target the respiratory system. In the present study we adapted heparin affinity chromatography to fractionate human plasma for functional bioassay. Fractions from pooled human plasma yielded particular plasma fractions with strong cough suppressing effects. Purification yielded a fraction that was finally identified as an activated blood coagulation factor fXIa using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI/TOF-MS). The fraction almost completely suppressed coughs induced by either chemical or mechanical stimulation applied to larynx or bifurcation of guinea-pig trachea. Cough suppressing effect of the fraction and commercially available fXIa were one million times stronger than codeine and codeine only partially suppressed the mechanically triggered coughing in animal model. Recent reviews highlighted prominent shortcomings of current available antitussives, including narcotic opioids such as codeine and their unpleasant or intolerable side effects. Therefore, safer and more effective cough suppressants would be welcome, and present findings indicate that fXIa in human plasma as a very promising, new therapeutic candidate for effective antitussive action.