Search

Data from previous experimental studies on the detection time of oxazepam and zopiclone in biological matrices are limited. The aim of this study was to examine the detection time in urine and oral fluid after single oral doses of oxazepam and zopiclone. Ten healthy volunteers received 25 mg of oxazepam in the evening of Day 1 and 7.5 mg of zopiclone in the evening of Day 3. Urine and oral fluid samples were collected twice daily for 9 days, with an additional sampling the day after ingestion of zopiclone. A total of 19 samples of both urine and oral fluid from each participant were analyzed using fully validated chromatographic methods. The median detection time for oxazepam was 91 h (range 73-108) in urine and 67 h (range 50-98) in oral fluid. The median detection time for zopiclone in urine was 49 h (range 25-98) and 59 h (range 48-146) in oral fluid. The metabolite zopiclone N-oxide showed a detection time of 36 h (range 25-84) in urine. The area under the concentration-time curve (AUCTotal) in urine corrected for creatinine was 150 μmol/L/mmol/L*h (range 105-216) for oxazepam and 1.60 μmol/L/mmol/L*h (range 0.79-4.53) for zopiclone. In oral fluid, the AUCtotal was 673 nmol/L*h (range 339-1,316) for oxazepam and 2,150 nmol/L*h (range 493-4,240) for zopiclone. In conclusion, oxazepam can be detected longer in urine than in oral fluid, while zopiclone can be detected longer in oral fluid than in urine. The high AUCTotal for zopiclone in oral fluid shows that the transfer into oral fluid is significant. In certain individuals the detection time of zopiclone in oral fluid is long. These results can be helpful when interpreting drug testing analyzes., (© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: In a pilot study, intranasal oxytocin was demonstrated to reduce the benzodiazepine dose needed to relieve withdrawal symptoms during alcohol detoxification. The aim of the present study was to compare the effect of oxytocin and placebo during a three-day period of alcohol detoxification at an addiction treatment center in Norway., Methods: Randomized, double-blind, placebo-controlled trial with 40 patients fulfilling criteria for ICD-10 diagnosis of alcohol dependence (F10.2), admitted for alcohol detoxification and withdrawal treatment. The benzodiazepine oxazepam was given as symptom-triggered treatment based on the scores of the Clinical Institute Withdrawal Assessment for Alcohol revised (CIWA-Ar) scale. Participants were randomized to receive either intranasal oxytocin (24 IU twice daily) or placebo., Primary Outcome: Oxazepam dose required to complete a three-day course of detoxification., Secondary Outcomes: Scores of the CIWA-Ar, the 10-item Hopkins Symptom Check List (HSCL-10), and self-reported total number of hours of sleep., Results: The mean total oxazepam dose (± standard deviation) was 56.8 ± 72.8 mg in the oxytocin group and 79.0 ± 122.9 in the placebo group (p = 0.490; difference -22.3 mg; 95% confidence interval (CI) -86.9 to +42.4 mg). The findings were inconclusive as to whether a difference in the CIWA-Ar score (5.94 ± 3.86 vs. 6.48 ± 3.92; p = 0.665) or in any of the other secondary outcomes was present. No serious adverse events were reported., Conclusion: Compared to placebo, intranasal oxytocin did not significantly reduce the oxazepam dose needed to complete a 3-day course of alcohol detoxification and withdrawal treatment., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

High-dose baclofen is prescribed as a maintenance treatment to reduce alcohol use in patients with alcohol use disorder. Nevertheless, some patients still have massive alcohol intakes and require inpatient alcohol withdrawal. To compare the oral dose of benzodiazepine prescribed to manage alcohol withdrawal symptoms in patients with vs. without steady-state pretreatment with high-dose baclofen. Retrospective chart review study. Prescribed benzodiazepine dose expressed in diazepam-equivalent was compared between groups. Thirty-one patients were assessed in the high-dose maintenance baclofen group and compared to 31 matched patients not receiving baclofen. No statistically significant difference was evident between groups regarding levels of benzodiazepines prescribed. The mean diazepam-equivalent dose during the first 7 days was 294 ± 149 mg in the baclofen group vs. 310 ± 133 mg (t-test = 0.440, P = 0.661) in matched controls. Steady-state high-dose baclofen before an inpatient alcohol cessation hospitalization does not lower the needed benzodiazepine dose in the management of alcohol withdrawal symptoms., (© 2017 Société Française de Pharmacologie et de Thérapeutique.)

Anxiolytic drugs, namely benzodiazepines, are the most commonly used psychoactive substances since anxiety disorders are prevalent mental disorders particularly in the Western world. Oxazepam is a short-acting benzodiazepine and one of the most frequently prescribed anxiolytic drugs. It is also the active metabolite of a wide range of other benzodiazepines, such as diazepam, ketazolam, temazepam, chlordiazepoxide, demoxazepam, halazepam, medazepam, prazepam, pinazepam, and chlorazepate. Therefore, relevant clinical and forensic outocomes may arise, namely those related to interference in driving performance. It is clinically available as a racemic formulation, with S-enantiomer being more active than R-enantiomer. In humans, it is mainly polimorphically metabolized by glucuronide conjugation at the 3-carbon hydroxyl group, yielding stable diastereomeric glucuronides (R- and S-oxazepam glucuronide). Relevant metabolic and stereoselective interspecies differences have been reported. In this work, the pharmacokinetics of oxazepam with particular focus on metabolic pathways is fully reviewed. Moreover, the metabolic profile of other prescribed benzodiazepines that produce oxazepam as a metabolite is also discussed. It is aimed that knowing the metabolism of oxazepam and related benzodiazepines may lead to the development of new analytical strategies for its early detection and help in further toxicological and clinical interpretations.

Background: Wastewater-based epidemiology is an alternative method for estimating the collective drug use in a community. We applied functional data analysis, a statistical framework developed for analysing curve data, to investigate weekly temporal patterns in wastewater measurements of three prescription drugs with known abuse potential: methadone, oxazepam and methylphenidate, comparing them to positive and negative control drugs., Methods: Sewage samples were collected in February 2014 from a wastewater treatment plant in Oslo, Norway. The weekly pattern of each drug was extracted by fitting of generalized additive models, using trigonometric functions to model the cyclic behaviour. From the weekly component, the main temporal features were then extracted using functional principal component analysis. Results are presented through the functional principal components (FPCs) and corresponding FPC scores., Results: Clinically, the most important weekly feature of the wastewater-based epidemiology data was the second FPC, representing the difference between average midweek level and a peak during the weekend, representing possible recreational use of a drug in the weekend. Estimated scores on this FPC indicated recreational use of methylphenidate, with a high weekend peak, but not for methadone and oxazepam., Conclusion: The functional principal component analysis uncovered clinically important temporal features of the weekly patterns of the use of prescription drugs detected from wastewater analysis. This may be used as a post-marketing surveillance method to monitor prescription drugs with abuse potential. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)

Background: According to the guidelines, benzodiazepines with a short half-life are the reference medication to treat alcohol withdrawal syndrome. The doses of oxazepam used in this population may reach up to 300 mg per day, significantly higher than usual doses. Its use in these patients deserves further information to confirm that the half-life remains constant and that no accumulation appears. The objective of this study was to investigate the pharmacokinetics of high doses of oxazepam in alcohol-dependent patients treated for alcohol withdrawal syndrome., Methods: Overall, 63 outpatients [weight, 71.1 kg (45.0-118.0); age, 47.6 years (31-67)] followed in the addictology unit, were studied. Total mean dose of 96.0 mg per day (range, 20-300 mg/d) was administered by oral route. Therapeutic drug monitoring allowed the measurement of 96 plasma concentrations. The following covariates were evaluated: demographic data (age, body weight, height, gender) and biological data (creatinine, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase). Pharmacokinetic analysis was performed using a nonlinear mixed-effect population model., Results: Data were modeled with a 1-compartment pharmacokinetic model. The population typical mean 90% confidence interval values for clearance, apparent volume of distribution (V), and duration of absorption (D1) were 6.8 L/h (range, 3.9-8.0 L/h), 159 L (range, 98.0-282 L), and 2 hours (fixed), respectively. The interindividual variability of clearance and V, and residual variability (90% confidence interval) were 74% (44%-96%), 69% (40%-89%), and 32% (20%-41%), respectively. The elimination half-life was 16 hours (range, 3-42 hours)., Conclusions: Oxazepam exhibited a linear pharmacokinetics with a proportional relationship from 20 to 300 mg per day, the dose range currently used in alcohol-dependent patients treated for alcohol withdrawal syndrome. We did not find any evidence of drug accumulation with these doses.

The study of animal behaviour is important for both ecology and ecotoxicology, yet research in these two fields is currently developing independently. Here, we synthesize the available knowledge on drug-induced behavioural alterations in fish, discuss potential ecological consequences and report results from an experiment in which we quantify both uptake and behavioural impact of a psychiatric drug on a predatory fish (Perca fluviatilis) and its invertebrate prey (Coenagrion hastulatum). We show that perch became more active while damselfly behaviour was unaffected, illustrating that behavioural effects of pharmaceuticals can differ between species. Furthermore, we demonstrate that prey consumption can be an important exposure route as on average 46% of the pharmaceutical in ingested prey accumulated in the predator. This suggests that investigations of exposure through bioconcentration, where trophic interactions and subsequent bioaccumulation of exposed individuals are ignored, underestimate exposure. Wildlife may therefore be exposed to higher levels of behaviourally altering pharmaceuticals than predictions based on commonly used exposure assays and pharmaceutical concentrations found in environmental monitoring programmes., (© 2014 The Author(s) Published by the Royal Society. All rights reserved.)

Although scientists have been investigating the neurobiology of psychomotor stimulant reward for many decades, there is still no FDA-approved treatment for cocaine or methamphetamine abuse. Research in our laboratory has focused on the relationship between stress, the subsequent activation of the hypothalamic-pituitary-adrenal (HPA) axis, and psychomotor stimulant reinforcement for almost 30 years. This research has led to the development of a combination of low doses of the cortisol synthesis inhibitor, metyrapone, and the benzodiazepine, oxazepam, as a potential pharmacological treatment for cocaine and other substance use disorders. In fact, we have conducted a pilot clinical trial that demonstrated that this combination can reduce cocaine craving and cocaine use. Our initial hypothesis underlying this effect was that the combination of metyrapone and oxazepam reduced cocaine seeking and taking by decreasing activity within the HPA axis. Even so, doses of the metyrapone and oxazepam combination that consistently reduced cocaine taking and seeking did not reliably alter plasma corticosterone (or cortisol in the pilot clinical trial). Furthermore, subsequent research has demonstrated that this drug combination is effective in adrenalectomized rats, suggesting that these effects must be mediated above the level of the adrenal gland. Our evolving hypothesis is that the combination of metyrapone and oxazepam produces its effects by increasing the levels of neuroactive steroids, most notably tetrahydrodeoxycorticosterone, in the medial prefrontal cortex and amygdala. Additional research will be necessary to confirm this hypothesis and may lead to the development of improved and specific pharmacotherapies for the treatment of psychomotor stimulant use., (© 2014 Elsevier Inc. All rights reserved.)

Rationale: Despite increased education regarding its dangers, cigarette smoking remains a significant public health concern due to serious associated health consequences such as cancer and respiratory and cardiovascular diseases. Most smokers fail in their attempts to quit smoking, and current pharmacological interventions have relatively low levels of efficacy and are associated with significant adverse events. We have previously reported that combinations of metyrapone and oxazepam, administered at doses that were ineffective when delivered singly, resulted in dose-related decreases in cocaine self-administration in rats while not affecting food-maintained responding during the same sessions., Objectives: The current study was designed to test the effects of the administration of a metyrapone:oxazepam combination on nicotine self-administration in rats., Methods: Several dose combinations of metyrapone (12.5, 25 or 50 mg/kg) and oxazepam (5 or 10 mg/kg) were tested in rats trained to intravenously (IV) self-administer nicotine (0.03 mg/kg/infusion) during 1-h self-administration sessions using both fixed-ratio and progressive-ratio (PR) schedules of reinforcement., Results: The administration of low doses of metyrapone and oxazepam in combination significantly decreased IV nicotine self-administration in rats. At the lowest doses of 12.5 mg/kg of metyrapone and 5 mg/kg of oxazepam, the drugs alone did not decrease IV nicotine self-administration, but the combination was effective. Varenicline was also tested using the fixed-ratio schedule, and reductions in nicotine intake were similar to those seen with the moderate dose of the combination., Conclusions: The results of this study suggest a potential utility of the combination of metyrapone and oxazepam for smoking cessation in humans.

Although cocaine dependence affects an estimated 1.6 million people in the USA, there are currently no medications approved for the treatment of this disorder. Experiments performed in animal models have demonstrated that inhibitors of the stress response effectively reduce intravenous cocaine self-administration. This exploratory, double-blind, placebo-controlled study was designed to assess the safety and efficacy of combinations of the cortisol synthesis inhibitor metyrapone, and the benzodiazepine oxazepam, in 45 cocaine-dependent individuals. The subjects were randomized to a total daily dose of 500 mg metyrapone/20 mg oxazepam (low dose), a total daily dose of 1500 mg metyrapone/20 mg oxazepam (high dose), or placebo for 6 weeks of treatment. The outcome measures were a reduction in cocaine craving and associated cocaine use as determined by quantitative measurements of the cocaine metabolite benzoylecgonine (BE) in urine at all visits. Of the randomized subjects, 49% completed the study. The combination of metyrapone and oxazepam was well tolerated and tended to reduce cocaine craving and cocaine use, with significant reductions at several time points when controlling for baseline scores. These data suggest that further assessments of the ability of the metyrapone and oxazepam combination to support cocaine abstinence in cocaine-dependent subjects are warranted.

The aim of this study was to explore how pharmaceutical micro-sized filler particles affect the amorphous stability of sucrose in sucrose/filler particle composites produced by freeze-drying. Focus was put on the filler particles' properties crystallinity, hygroscopicity, hydrophobicity, and surface area, and their influence on physical stability of the amorphous phase. The micro-sized filler particles were examined with Blaine permeametry, gas adsorption, pycnometry, gravimetric vapour sorption, X-ray diffraction, and light microscopy before composites of sucrose and micro-sized filler particles were prepared by freeze-drying. The stability of the composites was examined with X-ray diffraction, differential scanning calorimetry (DSC), and microcalorimetry. All composites were amorphous and showed higher stability compared to pure amorphous sucrose, which was evident from a delay in heat and moisture-induced crystallization. However, calcium carbonate and oxazepam micro-sized filler particles lost their ability to stabilize the amorphous sucrose when exposed to humidity. The dry glass transition temperature (T(g)) was higher for the composites, indicating the stabilization was mediated by a reduced molecular mobility of the amorphous phase., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Background: Often, long-term treatment with benzodiazepines is a subject of discussion due to potential side effects, with dependence on benzodiazepines as the most serous one. After longer period of benzodiazepines tolerance on their anxiolytic effects develops. Discontinuation is usually beneficial as it is followed by improved psychomotor and cognitive functioning, particularly in the elderly. Previous studies confirmed occurrence of physical dependence in high percentage of patients in long term treatment with benzodiazepines at therapeutic dosages. Benzodiazepines are relatively well-tolerated medicines but can induce serious problems of addiction and that is why their use is regulated. The aim of this article is to report a case of a patient who was taking 15 tablets of oxazepam daily for a period of time, during which reinforcement of irritability occurred., Conclusion: It is necessary to warn patients who take benzodiazepines in therapy that reinforcement of irritability may occur in case of higher dosage of benzodiazepines, which may be misinterpreted as worsening in mental condition.

Rationale: We have previously reported that pretreatment with benzodiazepines reduces intravenous cocaine self-administration in rats., Objective: This experiment was designed to investigate whether or not benzodiazepines would also inhibit the reinstatement of cocaine seeking induced by the presentation of a conditioned reinforcer., Materials and Methods: Adult male rats were implanted with jugular catheters and trained to self-administer cocaine (0.25 mg/kg/infusion) during daily 2-h sessions. During training, cocaine delivery was paired with the presentation of a tone and the illumination of a houselight. Once a stable baseline of cocaine self-administration was observed, lever pressing was extinguished to less than 20% of baseline rates. During reinstatement testing, responding resulted in the presentation of the conditioned reinforcer (i.e., the houselight and tone previously paired with self-administered cocaine)., Results: The response-contingent presentation of the conditioned reinforcer reliably reinstated cocaine seeking. Pretreatment with alprazolam (2 or 4 mg/kg, ip) or oxazepam (20 or 40 mg/kg, ip) reversed the conditioned reinforcer-induced reinstatement of extinguished cocaine-seeking behavior at doses that did not reliably affect the conditioned reinforcer-induced reinstatement of extinguished food seeking, suggesting that benzodiazepines may not have reduced reinstatement responding due to non-specific reductions in behavior., Conclusions: These data suggest that benzodiazepines may be useful in blocking the ability of environmental cues to stimulate cocaine seeking.

Aims: To measure and compare the concentration-time profiles of oxazepam and oxazepam glucuronide in blood, serum and oral fluid within the scope of roadside testing., Methods: Biological samples were collected from eight male subjects after ingestion of 15 or 30 mg oxazepam on separate dosing occasions with an interval of 7 days. The concentration-time profiles of oxazepam and oxazepam glucuronide were fitted by using a one-compartment model., Results: For oxazepam and oxazepam glucuronide, the mean oral fluid/blood ratios were 0.05 (range 0.04-0.07) and 0.004 (range 0.002-0.006), respectively. The concentration-time profiles in oral fluid paralleled those in blood., Conclusion: After oral administration of therapeutic doses of oxazepam, concentrations in oral fluid are very much lower than those in blood, and those of oxazepam glucuronide are much lower than those of the parent compound. Nevertheless, assay of oral fluid for oxazepam can be used to detect recent ingestion of the drug in drivers suspected of impaired driving performance.

Quantitative structure-property relationships were developed for predicting the enhancement of dissolution rate of the model lipophilic drug Oxazepam (Oxa) from blends (BLs) with 12 structurally different carriers at three different drug/carrier weight ratios (1/5, 1/10, and 1/20). To this end, 36 BLs were prepared by the solvent-evaporation method and characterized by spectroscopic (FT-IR), thermoanalytical (DSC) and X-ray diffraction studies. The dissolution rate of the examined systems was quantified by logDE/DE(Oxa), where DE and DE(Oxa) are the dissolution efficiencies of the BL and pure drug, respectively. Twenty molecular descriptors, including parameters for size, lipophilicity, cohesive energy density (CED), and hydrogen bonding capacity were calculated and together with the experimental melting point (MP), were used in multivariate analysis. Twelve pertinent variables were detected after looking at the results of principal component analysis (PCA) and cluster analysis, and reliable six-descriptor models generated by Partial Least Squares-Projection to Latent Structures (PLS) method. Satisfactory coefficient of determination values were obtained (i.e., R(2) equal to 0.794 and Q(2) equal to 0.705). The equations generated can predict with reasonable accuracy the dissolution rate increase of the model lipophilic drug/carrier BLs.

Objective: To describe associations between the use of benzodiazepines or related drugs (BZDs/RDs) and health, functional abilities and cognitive function in the elderly., Methods: A non-randomised clinical study of patients aged > or =65 years admitted to acute hospital wards during 1 month. 164 patients (mean age +/- standard deviation [SD] 81.6 +/- 6.8 years) were admitted. Of these, nearly half (n = 78) had used BZDs/RDs before admission, and the remainder (n = 86) were non-users. Cognitive ability was assessed by the Mini-Mental State Examination (MMSE). Patients scoring > or =20 MMSE sum points were interviewed (n = 79) and questioned regarding symptoms and functional abilities during the week prior to admission. Data on use of BZDs/RDs before admission, current medications and discharge diagnoses were collected from medical records. Health, physical abilities and cognitive function were compared between BZD/RD users and non-users, and adjustments were made for confounding variables. The residual serum concentrations of oxazepam, temazepam and zopiclone were analysed., Results: The mean +/- SD duration of BZD/RD use was 7 +/- 7 years (range 1-31). Two or three BZDs/RDs were concomitantly taken by 26% of users (n = 20). Long-term use of these drugs was associated with female sex and use of a higher number of drugs with effects on the CNS, which tended to be related to diagnosed dementia. After adjustment for these variables as confounders, use of BZDs/RDs was not associated with cognitive function as measured by the MMSE. However, use of BZDs/RDs was associated with dizziness, inability to sleep after awaking at night and tiredness in the mornings during the week prior to admission and with stronger depressive symptoms measured at the beginning of the hospital stay. Use of BZDs/RDs tended to be associated with a reduced ability to walk and shorter night-time sleep during the week prior to admission. A higher residual serum concentration of temazepam correlated with a lower MMSE sum score after adjustment for confounding variables., Conclusions: Long-term use and concomitant use of more than one BZD/RD were common in elderly patients hospitalised because of acute illnesses. Long-term use was associated with daytime and night-time symptoms indicative of poorer health and potentially caused by the adverse effects of these drugs.

Background: Depression is an international public health problem. The aim of this study was to compare the efficacy and tolerability of mirtazapine and fluoxetine treatment in a sample population consisting of Iranian patients suffering major depressive disorder., Methods: Thirty-six inpatients and outpatients with a diagnosis of major depressive disorder (Diagnostic and Statistical Manual of Mental Disorders-IV) and a score > or = 18 on the 17-item Hamilton Rating Scale for Depression (HAM-D-17) were randomly assigned to 6 weeks of treatment with mirtazapine (30 mg/day) or fluoxetine (20 mg/day). Efficacy was assessed by HAM-D-17. Information about adverse events was obtained by questioning of participants and/or their examination. Assessments were performed at weeks 0, 1, 2, 3, 4 and 6., Results: Sixteen of mirtazapine-treated patients and fifteen of fluoxetine-treated patients completed the 6-week study period. Both treatment groups were well matched at baseline with respect to demographic and disease characteristics. Both drugs showed a significant improvement over the 6 weeks of treatment (P < 0.001). There was no statistically significant difference between the mean +/- SEM HAM-D scores of two groups at weeks 1, 2, 3, 4, and at the end point. There were no significant differences between two groups in terms of response to treatment (> or = 50% decrease from baseline in HAM-D-17 total score) and remission (HAM-D-17 score of < or = 7). None of the differences in reported adverse events was statistically significant., Conclusion: In this study, mirtazapine and fluoxetine were equally effective and well tolerated after 6 weeks of treatment in patients with major depressive disorder.

Although additional dosages of benzodiazepines in long-term users of benzodiazepines are common, it is unknown whether these additional dosages resort any effect. The effects of an additional 20-mg dosage oxazepam were assessed in a double-blind, balanced-order, crossover randomized study comparing 16 long-term users of oxazepam (patients) with 18 benzodiazepine-naive controls (controls). The effects of 10 and 30 mg oxazepam were assessed at pretest and 2.5 hours after drug administration on: (a) saccadic eye movements as proxy for the sedative effect, (b) acoustic startle response (ASR) as proxy for the anxiolytic effects, (c) memory, (d) reaction time tasks, and (e) subjective measurements. Dose-related effects were found in patients on the peak velocity of saccadic eye movement and on response probability, respectively peak amplitude of the ASR. Comparison with controls, however, suggests that in patients the sedative effects might be mixed up with suppression of sedative withdrawal symptoms, whereas patients were as sensitive as benzodiazepine-naive controls for the effects of an additional dosage on the ASR. Neither 10 nor 30 mg oxazepam challenge affected the reaction time tasks in patients, whereas controls show a dose-related impairment. The memory impairing effects, however, did not differ significantly between patients and controls. In contrast to controls, patients could not discriminate between a 10- and 30-mg dosage as assessed by visual analogue scales and the STAI-DY-1, which might indicate a placebo effect in the 10-mg challenge in patients. We conclude that additional dosages of oxazepam still exert pronounced effects after daily use for more than 10 years.

A proposal that an endogenous benzodiazepine-like agent named endozepine-4 might be responsible for presentations of recurrent stupor has gained wide acceptance. A case of recurrent stupor over two decades is presented with many similarities to previous cases of "endozepine stupor". This case, however, was caused by exogenous benzodiazepine administration and serves as a warning to clinicians to beware of this diagnosis.

A fetal heart-rate pattern that has a reduced oscillation amplitude may indicate a physiological fetal dormant period but could also be an indication of fetal hypoxemia. In some rare cases such a fetal heart rate-pattern can be an indicator of cerebral or cardial fetal malformation or of an intoxication caused by sedative drugs. Our patient is a 32-year-old Para III in the phase of 29 weeks and 3 days gestation. Upon admission to the clinic, the fetal heart-rate pattern showed a reduced oscillation amplitude, and there were no signs of fetal movement. The ultrasound examination gave us no reason to suspect fetal malformation, and the results of the Doppler ultrasonography were also normal. However, although the patient had denied taking any medication at all, the results of an toxicological blood test confirmed our suspicion of benzodiazepine intoxication. Throughout the night the fetal heart-rate pattern was continuously measured, and in the early hours of the morning, after breaking down of the oxazepam medication, a normalization of the fetal heart-rate pattern was observed. This case report definitively demonstrates that Doppler ultrasonography is a valuable method for assessing any uncertainty regarding a fetal heart-rate pattern.

Patients aged 18 to 73 years and diagnosed with non-organic insomnia according to ICD-10 (F 51.0) were treated in a multicentre, double-blind, randomised parallel group comparison with either 600 mg/die valerian extract LI 156 (Sedonium) or 10 mg/die oxazepam taken for 6 weeks. A total of 202 outpatients with a mean duration of insomnia of 3.5 months at baseline were included at 24 study centres (general practices) in Germany. - Sleep quality (SQ) after 6 weeks measured by the Sleep Questionnaire B (SF-B; CIPS 1996) showed that 600 mg/die valerian extract LI 156 was at least as efficacious as a treatment with 10 mg/die oxazepam. Both treatments markedly increased sleep quality compared with baseline (p <0.01). The other SF-B subscales, i.e. feeling of refreshment after sleep (GES), psychic stability in the evening (PSYA), psychic exhaustion in the evening (PSYE), psychosomatic symptoms in the sleep phase (PSS), dream recall (TRME), and duration of sleep confirmed similar effects of both treatments. Clinical Global Impressions scale (CGI) and Global Assessment of Efficacy by investigator and patient, again, showed similar effects of both treatments. Adverse events occurred in 29 patients (28.4%) receiving valerian extract LI 156 and 36 patients (36.0%) under oxazepam, and were all rated mild to moderate. No serious adverse drug reactions were reported in either group. Most patients assessed their respective treatment as very good (82.8% in the valerian group, 73.4% in the oxazepam group). During the 6 week treatment phase Valerian extract LI 156 (Sedonium) 600 mg/die showed a comparable efficacy to 10 mg/die oxazepam in the therapy of non-organic insomnia.

Flumazenil (FLU), a benzodiazepine (BZD) partial agonist with a weak intrinsic activity, was previously found unable to precipitate withdrawal in tolerant subjects submitted to long-lasting BZD treatment. The potential use of FLU to treat BZD withdrawal symptoms has also been evaluated tentatively in clinical studies. In the present experiment, FLU (treatment A) was compared with oxazepam tapering (treatment B) and placebo (treatment C) in the control of BZD withdrawal symptoms in three groups of BZD dependent patients. Group A patients (20) received FLU 1 mg twice a day for 8 days, and oxazepam 30 mg in two divided doses (15 mg + 15 mg) during the first night, oxazepam 15 mg during the second night and oxazepam 7.5 mg during the third night. FLU was injected i.v. in saline for 4 hours in the morning and 4 hours in the afternoon, in association with placebo tablets. Group B patients (20) were treated by tapering of oxazepam dosage (from 120 mg) and with saline solution (as placebo) instead of FLU for 8 days. Group C patients (10) received saline instead of FLU and placebo tablets instead of oxazepam for 8 days. FLU immediately reversed BZD effects on balance task and significantly reduced withdrawal symptoms in comparison with oxazepam and placebo on both self-reported and observer-rated withdrawal scales. The partial agonist also reduced craving scores during the detoxification procedure. In addition, during oxazepam tapering, group B patients experienced paradoxical symptoms that were not apparent in FLU patients. Patients treated with FLU showed a significantly lower relapse rates on days 15, 23 and 30 after the detoxification week. Our data provide further evidence of FLUs ability to counteract BZD effects, control BZD withdrawal and normalize BZD receptor function. The effectiveness of FLU may reflect its capacity to upregulate BZD receptors and to reverse the uncoupling between the recognition sites of BZD and GABA, on the GABA(A) macromolecular complex, that has been reported in tolerant subjects.

Background: In alcohol withdrawal, fixed doses of benzodiazepine are generally recommended as a first-line pharmacologic approach. This study determines the benefits of an individualized treatment regimen on the quantity of benzodiazepine administered and the duration of its use during alcohol withdrawal treatment., Methods: We conducted a prospective, randomized, double-blind, controlled trial including 117 consecutive patients with alcohol dependence, according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, entering an alcohol treatment program at both the Lausanne and Geneva university hospitals, Switzerland. Patients were randomized into 2 groups: (1) 56 were treated with oxazepam in response to the development of signs of alcohol withdrawal (symptom-triggered); and (2) 61 were treated with oxazepam every 6 hours with additional doses as needed (fixed-schedule). The administration of oxazepam in group 1 and additional oxazepam in group 2 was determined using a standardized measure of alcohol withdrawal. The main outcome measures were the total amount and duration of treatment with oxazepam, the incidence of complications, and the comfort level., Results: A total of 22 patients (39%) in the symptom-triggered group were treated with oxazepam vs 100% in the fixed-schedule group (P<.001). The mean oxazepam dose administered in the symptom-triggered group was 37.5 mg compared with 231.4 mg in the fixed-schedule group (P<.001). The mean duration of oxazepam treatment was 20.0 hours in the symptom-triggered group vs 62.7 hours in the fixed-schedule group (P<.001). Withdrawal complications were limited to a single episode of seizures in the symptom-triggered group. There were no differences in the measures of comfort between the 2 groups., Conclusions: Symptom-triggered benzodiazepine treatment for alcohol withdrawal is safe, comfortable, and associated with a decrease in the quantity of medication and duration of treatment.

It has been described recently that low concentrations of benzodiazepines stimulate the transport activity of the neuronal glutamate transporter EAAT3, whereas high concentrations inhibit it. The present study is aimed to investigate whether benzodiazepines have similar effects on the two glial glutamate transporter, EAAT1 and EAAT2. To this end, the transporters were transiently expressed in CHO cells and transport activity was determined by isotope fluxes using D-aspartate as non-metabolizable homologue of L-glutamate. At low D-aspartate concentrations (1 micromol/l) EAAT1-mediated uptake was reduced significantly by low concentrations of oxazepam (1 micromol/l) and diazepam (1 and 10 micromol/l). At 100 micromol/l D-aspartate oxazepam stimulated EAAT1-mediated uptake up to 150% in a dose dependent manner, whereas the inhibition by low concentrations of diazepam was attenuated. In contrast, a significant effect of diazepam on EAAT2-mediated uptake was only observed at 1000 micromol/l where uptake was inhibited by 60%. A similar inhibition was observed for EAAT1. These studies demonstrate a different modulation of EAAT1 and EAAT2 by benzodiazepines. Furthermore the glial transporters differ from the neuronal glutamate transporter. Thus, a complex in vivo response of the various transporters to benzodiazepines can be expected.

Background: Divalproex sodium, an anticonvulsant and antikindling agent and gamma-aminobutyric acid enhancer, has been proposed as an alternative to benzodiazepines for treating alcohol withdrawal. This study reports on a randomized, double-blind, placebo-controlled trial of divalproex sodium in acute alcohol withdrawal., Methods: Thirty-six hospitalized patients experiencing moderate alcohol withdrawal as measured by a score of at least 10 on the revised Clinical Institute Withdrawal Assessment for Alcohol Scale (CIWA-Ar) were randomized to receive either divalproex sodium 500 mg three times per day for 7 days or matched placebo in a double-blind manner. All subjects received a baseline dose of oxazepam and had additional oxazepam available as a rescue medication in accordance with a standard, symptom-triggered detoxification protocol. Mean total milligrams of oxazepam received, progression of withdrawal symptoms, psychological distress as measured by the Symptom Checklist-90, side effects, and adverse outcomes were compared between groups., Results: Use of divalproex sodium resulted in less use of oxazepam (p < 0.033). Group differences seemed primarily driven by those subjects who experienced symptoms above threshold level (CIWA-Ar >or=10) after 12 hr. The progression in severity of withdrawal symptoms (increase in CIWA-Ar above baseline) was also significantly greater in the placebo group (p < 0.05)., Conclusions: This placebo-controlled pilot study suggests that divalproex sodium significantly affects the course of acute alcohol withdrawal and reduces the need for treatment with a benzodiazepine. A more aggressive loading dose strategy may demonstrate a more robust or earlier response.

Many patients with chronic obstructive pulmonary disease (COPD) suffer from osteoporotic pain as a result of glucocorticoid treatment and nervous symptoms partly related to their lung disease. There seems to be som reluctance to treat these patients with an opioid or benzodiazepine. Upon request, the Drug Information Centre in Odense made an extensive literature search on the subject. No documentation was found that tramadol additionally depresses the respiration in patients with COPD, nor has oxazepam in clinically relevant doses been found to exacerbate their lung disease. The clinical effect is subject to large interindividual variability, and the use of these drugs should, to a greater extent, rest on experience with the individual patient. There seems to be no reason to maintain a priori this rigoristic reluctance to use tramadol and/or oxazepam in patients with COPD.

Clinical aspects of the "night eating syndrome" (NES) are described. Recent studies, also referred to in the present report, have revealed certain triggering factors of this syndrome, but do not reveal the nature of the relationship between awakening and compulsory need for food. According to the psychodynamic interpretation, these subjects eat at night to replace dreaming, to which they offer strong resistance, whilst according to the psychobiological interpretation, motivational stimuli develop the irresistible and repeated desire for food. Within a post-rational cognitive theoretical model, the compulsion to food would be the mode through which subjects obtain a modified conscious state necessary to appease the suffering due to an experience of emptiness and incapacity. Psychological support associated with pharmacological treatment (benzodiazepine, gamma-hydroxybutyric acid) has been shown, in a personal series, to be effective both upon the sleep disorder and craving.

A variety of detoxification methods have been utilized for the treatment of heroin withdrawal before individuals begin long-term opiate-free and naltrexone programs. While methadone in decreasing doses is still widely used for detoxication procedures, rapid and ultrarapid protocols including clonidine and opiate receptors antagonists have been proposed. This study compares the efficacy of different detoxification methods and investigates possible changes in naltrexone compliance. Ninety-eight heroin-addicted individuals were studied to evaluate withdrawal symptoms, craving, mood, urine toxicologic screens, and drop-out rate during therapy with: Group A: clonidine only (5 days); Group B: clonidine, oxazepam, baclofen, and ketoprofene with naloxone and naltrexone (2 days); and Group C: methadone in decreasing doses (10 days). Naltrexone compliance and relapse rates were evaluated during a 6-month follow-up period. Rapid detoxification with opiate antagonists (Group B) induced slight and transient withdrawal symptoms, and resulted in a significantly lower percentage of heroin catabolites in urine controls during the detoxification procedure, lower negative and positive craving, less mood problems, and higher compliance in extended naltrexone treatment. In comparison with clonidine only (Group A) and methadone (Group C), the early use of naltrexone during detoxification in combination with benzodiazepines and clonidine facilitated extended naltrexone acceptance and improved the recovery outcome in outpatients.

Charts of patients hospitalized for uncomplicated alcohol withdrawal were examined and detoxification practices compared. Patients detoxified using a Clinical Institute Withdrawal Assessment for Alcohol-revised (CIWA-Ar) based PRN protocol on the addiction unit received significantly fewer chlordiazepoxide milligram equivalents over shorter duration than patients managed by other detoxification methods on other hospital units. Significantly fewer patients received benzodiazepines in the CIWA-Ar protocol managed group, but inter-group differences (p < 0.01) remained when only medicated patients were compared. Differences between the protocol and non-protocol groups did not reach statistical significance when PRN only strategies were examined, suggesting that the use of a symptom-triggered strategy may account for the noted effects.

We report the successful use of valproate in a 44-year-old woman with migraine induced by selective serotonin reuptake inhibitors. Valproate should be considered for those patients who develop serious migraine for the first time, or worsening of previous migraine, after the initiation of treatment with selective serotonin reuptake inhibitors and for whom continued treatment with this class of drugs is important.

Some institutionalized elderly persons need a sedative prior to a dental examination or treatment because they have a disturbance due to physical illnesses, degenerative changes in the brain, and/or psychiatric disorders, associated with advanced aging. Oral administration is one of the safest methods of delivery of a sedative drug. It is almost universally acceptable, easy to administer, costs little, has a low incidence and severity of adverse reactions, and requires no additional formal specialized training for the dentist. However, theoretical and practical knowledge of sedation is essential. This paper reviews the literature on oral sedation for the geriatric patient. Benzodiazepines are most often used for oral sedation of geriatric patients. The properties of these drugs were reviewed, and recommendations were made with respect to the drugs of choice and their dosage. Generally, fast-acting benzodiazepines of short duration, with rapid rate of elimination and no active metabolites, are recommended. The drug of choice, and the dosage, may vary according to the medical history and physical condition of the patient.

By using otoacoustic emission, we looked for change in outer hair cell (OHC) motile activity and medial olivocochlear (MOC) system inhibition due to benzodiazepine administration, a drug that is known to produce a pharmacological effect by interacting with GABAergic inhibitory neurotransmission. No effect was observed on OHC motile activity, in contrast benzodiazepines decreased MOC system effectiveness suggesting the existence of GABAergic fibers projecting onto the MOC system.

In our experiments a drug from the group of 5-HT3 antagonists--ondansetron (OND)--has been used in rats developing tolerance to oxazepam (OXZ). After 7 days of oxazepam administration (5 mg/kg i.p.) a significant decrease in the anxiolytic behavior was observed in the Crawley test. In the rats already partly tolerant to oxazepam, an undiminished anxiolytic-like effect of ondansetron (single injection of 0.1 mg/kg i.p., seventh day) was observed. After 14 days of oxazepam administration its anxiolytic activity was even more diminished. A single injection of ondansetron 0.1 mg/kg restored the anxiolytic behavior: rise of BWT (black-white transition) and WSE (white square entrance). After 21 days the anxiolytic activity of oxazepam was totally abolished and the single injection of ondansetron did not restore the state of anxiolysis. The results show that the anxiolytic effects of ondansetron were not influenced in the first stages of tolerance development to oxazepam, but the drug was not able to produce an anxiolytic effect in the state of full tolerance to oxazepam (after 3 weeks).

Changes in body weight (BW) in female rats treated for 5 weeks (wk) with weekly subcutaneous implantation of silastic capsules containing different benzodiazepines (BZs): diazepam (DZ) 90, 180, 360 and 540 mg wk-1; nordiazepam (ND) 600 mg wk-1; oxazepam (OX) 600 mg wk-1 and flunitrazepam (FN) 540 mg wk-1 and in male rats exposed to DZ (540 mg wk-1) were evaluated herein. Rats (female and male) implanted with empty capsules served as controls. The BW gain was significantly higher in male than in female rats (both DZ-treated and controls). The BW gain increased with increasing doses of DZ but slowed with time of exposure. In comparison to control rats, the BW gain was significantly higher in DZ-(540 mg wk-1) and OX- but not in ND- and FN-treated female rats. However, the differences between BZs were not of statistical significance. In rats exposed to empty capsules (male, female); DZ (male); ND and OX (female) the BW gain increased with time (1-4 wk) while in rats exposed to DZ and FN (female) the BW stabilised within 2 wk. Acute injection of the central BZ receptor antagonist, flumazenil (40 mg kg-1, i.v., 5th wk of chronic exposure), tended to inhibit the time-related BW gain in rats exposed to empty capsules (male, female), DZ (male), ND and OX (female) but did not affect the BW in DZ- (540 mg wk-1) and FN-exposed rats (female) where BW stabilised prior to FLU injection. Repeated administration of flumazenil (30 mg kg-1 wk-1, i.p.) did not affect the BW gain in DZ- and ND-treated female rats. The present data indicate that different BZs have different effects on BW gain in the rat suggesting that different subtypes of BZ receptors are involved.

The authors examined characteristics of successful completers of an outpatient clonidine/oxazepam detoxification procedure for opioid dependence. Of 215 initial applicants, 167 received medication, and 65 successfully completed by taking a dose of naltrexone. Those who completed were more likely to have last used an opioid other than heroin, to be heroin smokers, rather than intravenous users, to have used benzodiazepines in the 30 days before treatment, and to have abstained from opioids for a longer time before presenting for treatment. New users (for less than 2 years) did no better than those using longer than 2 years. These findings may help in the continued refinement of patient placement criteria.

Buprenorphine (BUP) is an alternative to methadone (METH) maintenance. However, there are few studies on the switching of patients from METH to BUP. Eighteen volunteers who had been maintained on METH for 1-19 years were recruited for a residential cocaine self-administration study. All subjects were maintained on 60 mg METH for up to 1 1/2 weeks before the 7-day changeover (60, 40, 30, 30, 0 mg METH; 4, 8 mg BUP). Fifteen subjects successfully completed the transfer from METH to BUP, experiencing moderate withdrawal symptoms, as measured by the Subjective Opiate Withdrawal Scale (SOWS). Withdrawal symptoms were the highest during the first assessment of the day, at the time of BUP administration. SOWS scores returned to baseline 4 days after the switchover. This study demonstrates that within a supportive inpatient setting, research volunteers can be rapidly switched from high-maintenance doses of METH to BUP with an acceptable degree of tolerability.

The lowest dose of alprazolam, diazepam, flunitrazepam and oxazepam consistently to induce loss of righting reflex in squirrel monkeys or vehicle was orally administered to monkeys on 18 consecutive days: 2 mg/kg alprazolam (n = 4), 30 mg/kg diazepam (n = 4), 1 mg/kg flunitrazepam (n = 4), 280 mg/kg oxazepam (n = 5), or vehicle (n = 4). Tolerance developed rapidly for loss of righting reflex, more slowly for sleep and only minimally for muscle relaxation observed during the period immediately following daily oral administration. Injection of the specific benzodiazepine receptor antagonist flumazenil (10 mg/kg i.v.) 5 h after the ninth daily oral treatment produced signs of precipitated withdrawal (tremor, vomiting and/or convulsions) in one alprazolam-, four diazepam-, one flunitrazepam- and four oxazepam-treated monkeys, but not in the vehicle-treated monkeys. Physiological saline injected intravenously several days later under these same experimental conditions failed to provoke a precipitated withdrawal reaction. When flumazenil-induced precipitated withdrawal was again evaluated after the 18th daily oral treatment, withdrawal signs were observed in all alprazolam- and all diazepam-treated monkeys, as well as in three flunitrazepam- and three oxazepam-treated monkeys, but not in the vehicle-treated monkeys (convulsions were observed in one alprazolam-, two diazepam-, one flunitrazepam- and two oxazepam-treated monkeys). No signs of spontaneous withdrawal were observed in any of the monkeys during a subsequent 3-week drug-free period. Thus, repeated administration of approximately equieffective doses of these four benzodiazepines resulted in a similar development of tolerance and physical dependence (indicated by the occurrence of a precipitated withdrawal reaction).

Oxazepam has been determined to be a potent hepatocarcinogen in mice. Evidence in the literature indicates that oxazepam is capable of inducing drug metabolizing enzymes in rodents and an association between enzyme induction and carcinogenesis has been proposed for other compounds such as phenobarbital. We examined the pattern of enzyme induction that occurs under bioassay conditions in male B6C3F1 mice. The results indicate that oxazepam is capable of inducing multiple drug metabolizing enzymes under bioassay conditions. Closer examination of the most induced samples suggests that oxazepam is a phenobarbital-type enzyme inducer.

Transurethral microwave thermotherapy (TUMT) can be painful. Pain sensation limits treatment tolerance and consequently also treatment efficacy. Of our population of patients treated with TUMT, 22% (63/288) needed intravenous analgesia and, nevertheless, 6% (17/288) needed definitive treatment interruption. The aim of this study was to identify the mechanism of pain sensation during TUMT and to verify whether the prophylactic use of a sedative drug would improve treatment tolerance. Eighty-three patients undergoing TUMT treatment for benign prostatic hyperplasia at our department entered a prospective, randomized, single-blinded study. Thirty minutes before treatment, 40 patients (group A) received 960 mg cotrimoxazole orally while 43 patients (group B) received 960 mg cotrimoxazole and 10 mg oxazepam, both orally. Statistically significant improvement in treatment tolerance in group B in comparison with group A was found. Pain sensation during TUMT seemed to be mostly due to anxiety. It is concluded that the prophylactic use of a sedative drug is advisable in patients undergoing TUMT in order to improve treatment tolerance.

Oxazepam has recently been shown to induce hepatocarcinogenicity in B6C3F1 mice. Due to the widespread human exposure to this anxiolytic compound and other structurally similar benzodiazepines, we conducted toxicity and cell proliferation studies on oxazepam to determine possible mechanisms whereby this nonmutagenic chemical may have exerted a carcinogenic effect. Male B6C3F1 mice (10 per dose-time group) received diets containing oxazepam at 0, 25, 125, 2500, and 5000 ppm. Mice were treated for 15, 30, 45, or 90 days, at which time they were evaluated for feed consumption, liver/body weight ratios, clinical pathology, serum oxazepam levels, and histopathology of the liver. During the final 7 days before sacrifice, the mice were exposed to BrDU via osmotic minipump to quantify hepatocellular replicative DNA synthesis. Few effects were observed resulting from chronic exposure to oxazepam other than statistically significant, dose-related increases in liver/body weight ratios. Replicative DNA synthesis was significantly increased in a dose-related manner at the 15-day time point in the 125, 2500, and 5000 ppm dose groups, and attained levels of four- to five-fold above control levels which returned to control levels by 30 days. The lack of significant toxicity, sustained increased liver/body weight ratios, and the rapid and transient induction of replicative DNA synthesis are similar to the effects reported for exposure to another widely used therapeutic agent shown to be a nongenotoxic carcinogen, phenobarbital.

The benzodiazepines are a class of drugs that are widely used in the treatment of various psychiatric disorders. One member of this class, oxazepam, is also a common metabolite of several other benzodiazepines. Since the evidence for the genetic toxicity and carcinogenic properties of these compounds is inconsistent, we investigated the oxazepam-induced formation of micronuclei in Syrian Hamster embryo fibroblast (SHE) cells, human amniotic fluid fibroblast-like (AFFL) cells and L5178Y mouse cells. A dose-dependent increase in micronucleus fractions was found in all three cell lines. The time course of micronucleus induction in L5178Y cells showed a maximum at 5 h after treatment, suggesting that the micronuclei were formed in the first mitosis after treatment. Kinetochore staining (CREST-antiserum) revealed the presence of kinetochores in approximately 50% of the micronuclei in all three cell types. This result was further confirmed by in situ hybridization in L5178Y cells and indicates the presence of whole chromosomes or centric fragments as well as acentric fragments in the oxazepam-induced micronuclei. The L5178Y cells did not show a mutagenic response to oxazepam at any of the doses or expression times used.

A computer model for predicting blood/plasma concentrations of test chemicals in dosed feed and dosed drinking water toxicology studies was developed. The model was constructed based on linear theory. The animal's feeding and drinking habits and the linear disposition kinetics of the test chemical obtained after a bolus gavage dose were built into the model. Blood/plasma concentrations of oxazepam and pentachlorophenol in dosed feed and dosed drinking water studies were predicted and compared with the experimentally determined data. The model proved highly reliable in predicting the blood/plasma concentrations of test chemical in dosed feed and dosed drinking water studies. The results suggest that if the kinetics of test chemicals fit a one-compartment model then bioaccumulation of the test chemical will occur in dosed feed or in dosed drinking water studies when absorption half-lives are less than 1.38 hr and elimination half-lives are longer than 5 hr. The extent of accumulation is mainly dependent on the elimination half-lives. For chemicals with absorption half-lives less than 1.38 hr and elimination half-lives less than 2 hr, the extent of bioaccumulation will be minimal. Blood/plasma concentrations of test chemicals in rats and mice will fluctuate daily and a quasi-steady state will be achieved after ad libitum exposure to dosed feed or dosed drinking water for approximately 4 days. If a daily 12-hr light cycle is used with the light cycle starting at 7:00 AM, the expected peak and trough blood concentrations in dosed feed studies will occur approximately in the early morning (5:00 AM) and in the late afternoon (4:00 PM), respectively. Similar results were obtained for dosed drinking water studies. The model should be applicable to dosed feed and dosed drinking water studies using other species.

1. The purpose of this investigation was to examine the influence of increasing age on the pharmacokinetics and the time course of the anticonvulsant response of oxazepam in BN/BiRij rats as an animal model of aging. 2. Oxazepam was administered intravenously in a dose of 12 mg kg-1 body weight and the anticonvulsant effect intensity was measured as elevation above baseline of a threshold for induction of localized seizure activity (TLS). Direct cortical stimulation with ramp shaped electrical pulse trains of increasing intensity was used to determine this threshold. 3. The pharmacological effect vs. time profile showed in young rats an anticonvulsant component followed by proconvulsant component which is suggestive for the occurrence of acute tolerance and/or withdrawal syndrome. With increasing age the proconvulsant component disappeared, resulting in a monophasic effect profile (anticonvulsant effect only) at the age of 35 months with significantly higher anticonvulsant effect intensity immediately following drug administration. No age-related changes in the pharmacokinetic parameters of oxazepam were observed. 4. In five animals of each age group, benzodiazepine receptor binding characteristics were determined in vitro with [3H]-flunitrazepam as a ligand. Both receptor density and affinity did not show age-related changes. Available literature data on post-receptor events do not indicate conclusive age-related changes. 5. It is concluded, that the observed change in the pharmacodynamics of anticonvulsant effect of oxazepam can be explained by the disappearance of the tolerance/withdrawal phenomenon. This is compatible with a decreased efficiency of homeostatic control mechanisms in the elderly.

A large number of benzodiazepines have been studied for use as sedatives and for their anxiolytic potential as premedicants for outpatient surgery. Potent, new, orally-administered drugs with short half-lives, rapid onset, and minimal residual effects have been developed. Dose-dependent amnesia is also produced by some of these agents. Advances in understanding receptor physiology have shed light on specific pharmacologic activities and aided the discovery of benzodiazepine antagonists with antidote properties. While these drugs have relatively low toxicity, dose-related oversedation remains a risk in susceptible patients, especially when combined with other sedatives.

Growth and neurodevelopment at 6, 10 and 18 months of age have been studied prospectively and longitudinally in a series of 17 children born to mothers who used benzodiazepines (BZD) in therapeutic doses as their only psychotropic drug throughout pregnancy. The results were compared with a group of 29 children born to mothers without any known use of psychotropic drugs. The BZD-exposed children caught up their low mean birth-weight, at an early stage, whereas the slightly decreased head circumference at birth remained at the same low level. In five infants, a pattern of craniofacial anomalies was found. Deviating neurodevelopmental and clinical symptoms and signs were common. The gross motor development was retarded at 6 and 10 months, but was nearly normal at 18 months. Impaired fine motor functions were found on all follow-up occasions. At 18 months, the most prominent finding was a delayed development of pincer grasp. The BZD-exposed children showed deviations in muscle tone and pattern of movements more frequently than children in the reference group. The study suggests that the use of BZD in therapeutic doses throughout pregnancy can have negative effects on the development of children up to 18 months of age. The long-term hazards cannot be evaluated from these results. A further follow-up at early school age is needed and is in progress.

Twenty percent of the Swiss albino mice administered with a single dose (60 mg/kg) of oxazepam dissolved in dimethyl sulphoxide (DMSO) died within 7 days. Similarly high mortality rate (37%) was observed in diazepam sensitive mice derived from a Swiss albino stock. In contrast, zero mortality was observed in Swiss albino mice administered with DMSO or diazepam (35 mg/kg). Mortality at 60 mg/kg diazepam was only 10%. The high mortality caused by oxazepam in Swiss albino mice seemed to be strain-related as only 7% mortality was observed with identically treated BALB/c mice. Since DMSO is the only convenient vehicle for the administration of oxazepam by injection, it is suggested that a suitable strain must be selected for experimentation in order to avoid unnecessary loss of animals.

Ten different doses of oxazepam (ranging from 7.5 to 50 mg) or placebo were administered to a total of 28 female subjects in three separate studies. Subjects completed a battery of psychometric tests at 1 and 2 h postdose. The tests included critical flicker fusion, choice reaction time and a tracking task. Following separate analyses of variance, effect sizes (Cohen's d) were calculated for each dose at each dependent variable. These effect sizes were then correlated with the dose of drug administered, using regression analyses. It was found that the doses correlated highly with most of the psychometric variables determined, implying that the test battery is sensitive to drug effects.