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Smokeless tobacco is widely used by athletes to enhance performance. Nicotine is a central nervous system stimulant and acts on cardiocirculatory and metabolic systems, involving tissue blood flow and circulatory vasoreactivity. The aim of this study was to investigate the effects of the oral smokeless tobacco (Swedish snus (SS)) on the perception of fatigue and time to exhaustion (TTE) during moderate-intensity aerobic exercise. Comparing SS with SP tests, significant differences (p, This work was supported by research funds allocated to the following departments at the University of Verona: Neurosciences, Biomedicine and Movement Sciences, and Diagnostic and Public Health.

In order to improve the economic sustainability of the Jatropha-biofuel chain, seed cake detoxification and utilization of ‘non toxic’ Jatropa curcas accessions are the main activities pursued with the aim of using J. curcas seed cake in animal feed. Given this growing interest, a robust and reliable method for phorbol esters (PEs) determination is necessary. HPLC-UV is a well-established method to detect and quantify the PEs content in Jatropha seeds and related products, but it seems to be unsuitable for more complex matrices like Jatropha leaves and animal tissues, due to the presence of interfering compounds. The objective of this work was to develop and optimize a LC–MS/MS method for the quantitative determination of PEs in seeds and leaves of J. curcas L. plants from Ghana and Mexico and in liver (as an organ with the function of accumulation) from goats fed with PEs in their diet. The HPLC-UV analysis evidenced five chromatographic peaks in the toxic seed kernels corresponding to the factors C1, C2, C3, C6 and C4–C5, respectively, with a PEs concentration of about 5100 μg/g (as TPA equivalent). No PEs related peaks were detected in Mexican kernel seeds while in the case of leaves and liver the analysis was hampered by the presence of interfering compounds. The toxic kernel seed extract was used as a standard solution for the PEs quantitation in leaves and liver samples by LC–MS/MS, with the standard addition method. The most intense MRM transitions used to quantify and qualify the PEs were: 675 → 311, 693 → 311, and 293 → 265 m/z. The LC–MS/MS method with a LOD and a LOQ of 0.07 and 0.21 μg/g, respectively, resulted in more sensitivity and selectivity than the HPLC-UV method. All three MRM transitions were present in Ghanaian toxic kernel seed, while no peaks were present in the supposed non-toxic Mexican kernel seed. PEs concentration in the leaves of toxic Ghanaian accession resulted in about 1/10 of that in the kernel, while no PEs peaks were found in the J. curcas leaves from Mexico and in liver samples.

A rapid, selective and sensitive isocratic reversed-phase HPLC assay coupled with MS/MS detection for simultaneous quantification of fluoxetine and its major active metabolite in serum samples has been developed. Analytes were extracted with a simple three step liquid-liquid procedure and chromatographic separation was achieved on a C18 column. Because of its sensitivity, this HPLC/MS/MS method is suitable both for routine therapeutic drug monitoring and for pharmacokinetic studies, due to its low limits of quantification.

Therapeutic drug monitoring (TDM) is essential to maintain the efficacy of many immunosuppressant drugs while minimizing their toxicity. TDM of mycophenolate mofetil requires area under the curve AUC determinations but appears laborious, costly, and clinically impractical. To overcome these problems, limited sampling strategies (LSS) have been proposed in adult and pediatric renal transplant patients. The purpose of this study was to develop an LSS in heart transplant patients. Forty-four mycophenolic acid (MPA) full AUC(0-12h) profiles were generated by high-performance liquid chromatography in nine heart transplant patients during the first 12 weeks posttransplant. Each patient received concomitant cyclosporine and prednisone therapy. Multiple stepwise regression analysis was used to define the time points of MPA levels to explain the MPA AUC(0-12h). Agreement between abbreviated AUC and the full AUC(0-12h) was tested by means of a Bland and Altman analysis. The highest coefficient of determination r(2) among MPA AUC and single concentrations (r(2) = .610) was observed with C(2), while C(12) provided the lowest one (r(2) = .003). Stepwise linear regression showed that the minimal model with the best estimation of MPA AUC(0-12h) was obtained at timed values of 1.25, 2, and 6 hours. The corresponding estimated model was AUC = 5.568 + 0.902 * C(1.25) + 2.022 * C(2) + 4.594 * C(6) (r(2) = .926). Bland and Altman analysis revealed good agreement between predicted AUC and full AUC. A further interesting model equation obtained by four samples was AUC = 3.800 + 1.015 * C(1.25) + 1.819 * C(2) + 1.566 * C(4) + 3.479 * C(6) (r(2) = .948).

A rapid, selective and sensitive isocratic reversed-phase HPLC method for the simultaneous determination of oxcarbazepine, its main metabolites (mono and dihydroxycarbazepine), lamotrigine, carbamazepine and carbamazepine-epoxide in plasma samples has been implemented. Analytes were extracted on solid-phase cartridges (SPE) and chromatographic separation was achieved on a Zorbax SB-CN column. The chromatographic peak area ratio based on UV absorbency at 214 nm was used for quantitative analysis. This HPLC method has been successfully used for routine evaluation to monitor plasma concentrations in epileptic patients referred to our institute and for pharmacokinetic studies regarding patients cotreated with drugs inducing or inhibiting OXC metabolism.

Posaconazole and voriconazole, two triazole antifungal agents, are used for the prophylaxis and treatment of invasive mycoses in patients with acute myeloid leukaemia and/or immunocompromised. Inter- and intra-patient variability of pharmacokinetics, drug-drug interactions, serum concentration related toxicity and success of therapy has stressed the need of frequently therapeutic drug monitoring of both drugs. Therefore, a rapid, selective and sensitive isocratic reversed-phase HPLC assay coupled with Mass spectrometry detection for quantification of posaconazole and voriconazole in serum samples has been developed. Analytes were extracted on solid-phase cartridges (SPE) and chromatographic separation was achieved on a C8 column and detected by mass spectrometry in positive ion mode with the select ion monitoring (SIM) mode. The total chromatographic running time was 6 minutes. The method was successfully used for a pharmacokinetic study but, thanks to its rapidity and selectivity, it’s also suitable for routinarly therapeutic drug monitoring (TDM).

Combination therapy with interferon-α and ribavirin is considered the treatment of choice for chronic hepatitis C. However, interferon-α may induce severe depression. It has been suggested that interferon-α is able to modify cytochrome P450 (CYP) 1A2 and 2D6 activity. We therefore decided to study the effects of the interferon-α-2b pegylated derivative on fluoxetine disposition in patients receiving combination chemotherapy for chronic hepatitis C. After approval by the institutional ethics committee, 20 adult patients with chronic hepatitis C, but with no history of other liver diseases, were prospectively admitted to the study, which included phenotyping by means of a dextromethorphan test and evaluation of fluoxetine and norfluoxetine pharmacokinetic parameters (the area under the serum concentration-time curve, maximum serum concentration, time to reach the maximum serum concentration and terminal elimination half-life) before and after 2 months of continuous peginterferon-α-2b therapy. The only statistically significant difference we observed was a significant reduction in the terminal elimination half-life of fluoxetine (from 47.30 to 33.23 hours; p =0.014) after peginterferon-α-2b treatment. These data suggest that interferon-α may induce, rather than inhibit, the biotransformation of fluoxetine.

A rapid, selective and sensitive isocratic reversed-phase HPLC assay coupled with UV detection for quanti fi cation of ketorolac in serum and synovial fl uid samples has been developed. Analytes were extracted on solid-phase cartridges (SPE) and chromatographic separation was achieved on a C18 column. The chromatographic peak area ratio based on UV absorbency at 313 nm was used for quantitative analysis. This HPLC method has been successfully used for routine evaluation to monitor serum and synovial fl uid concentrations in reumathologic patients affering to our institute. Thanks to its sensitivity, this HPLC/UV method is also suitable for pharmacokinetic studies.

The objective of the present retrospective observational study carried out in patients receiving a standard dosage of linezolid and undergoing routine therapeutic drug monitoring (TDM) was to assess the interindividual variability in plasma exposure, to identify the prevalence of attainment of optimal pharmacodynamics, and to define if an intensive program of TDM may be warranted in some categories of patients. Linezolid plasma concentrations (trough [ C min ] and peak [ C max ] levels) were analyzed by means of a high-performance liquid chromatography (HPLC) method, and daily drug exposure was estimated (daily area under the plasma concentration-time curve [AUC 24 ]). The final database included 280 C min and 223 C max measurements performed in 92 patients who were treated with the fixed 600-mg dose every 12 h (q12h) intravenously ( n = 58) or orally ( n = 34). A wide variability was observed (median values [interquartile range]: 3.80 mg/liter [1.75 to 7.53 mg/liter] for C min , 14.70 mg/liter [10.57 to 19.64] for C max , and 196.08 mg·h/liter [144.02 to 312.10 mg·h/liter] for estimated AUC 24 ). Linezolid C min was linearly correlated with estimated AUC 24 ( r 2 = 0.85). Optimal pharmacodynamic target attainment (defined as C min of ≥2 mg/liter and/or AUC 24 /MIC 90 ratio of >80) was obtained in about 60 to 70% of cases, but potential overexposure (defined as C min of ≥10 mg/liter and/or AUC 24 of ≥400 mg·h/liter) was documented in about 12% of cases. A significantly higher proportion of cases with potential overexposure received cotreatment with omeprazole, amiodarone, or amlodipine. Our study suggests that the application of TDM might be especially worthwhile in about 30% of cases with the intent of avoiding either the risk of dose-dependent toxicity or that of treatment failure.

Objective: TO describe the management of a pharmacokinetic interaction between azole antifungals (fluconazole and voriconazole) and everolimus in a patient who underwent an orthotopic liver transplant. Case Summary: A 65-year-old male who received an orthotopic liver transplant experienced an iatrogenic retroperitoneal duodenal perforation on postoperative day 55. His condition was subsequently complicated by severe sepsis and acute renal failure. Intravenous fluconazole 400 mg, followed by 100 mg every 24 hours according to impaired renal function, was immediately started; to avoid further nephrotoxicity, immunosuppressant therapy was switched from cyclosporine plus mycophenolate mofetil to oral everolimus 0.75 mg every 12 hours. Satisfactory steady-state minimum concentration (Cmin) of everolimus was achieved (∼5 ng/mL). On day 72 posttransplant, because of invasive aspergillosis, antifungal therapy was switched to intravenous voriconazole 400 mg every 12 hours on the first day, followed by 200 mg every 12 hours; to prevent drug toxicity, the everolimus dosage was promptly lowered to 0.25 mg every 24 hours. At that time, the everolimus Cmin averaged approximately 3 ng/mL. The concentration/dose ratio of everolimus (ie, Cmin reached at steady-state for each milligram per kilogram of drug administered) was markedly lower during fluconazole versus voriconazole cotreatment (mean ± SD, 3.49 ± 0.29 vs 11.05 ± 0.81 ng/mL per mg/kg/daily; p < 0.001). Despite intensive care, the patient's condition continued to deteriorate and he died on day 84 posttransplant Discussion: Both azole antifungals were considered probable causative agents of an interaction with everolimus according to the Drug Interaction Probability Scale. The Interaction is due to the inhibition of CYP3A4–mediated everolimus clearance. Of note, prompt reduction of the everolimus dosage since the first azole coadministration, coupled with intensive therapeutic drug monitoring, represented a useful strategy to prevent drug overexposure. Conclusions: Our data suggest that during everolimus-azole cotreatment, a dose reduction of everolimus is needed to avoid overexposure. According to the different inhibitory potency of CYP3A4 activity, the reduction should be lower during fluconazole than during voriconazole cotreatment.

Background In order to study a model that maximizes gastric cancer tissue and lymph node exposure to antineoplastic drugs while simultaneously reducing their systemic bioavailability, we implemented a preliminary investigation of the disposition of a daunorubicin liposomal preparation (D) in gastric cancer patients by means of gastric submucosa injection. Method After a dose finding study, 12 patients (candidates for gastric resection because of gastric cancer) were studied by administering two doses of 50 mg of D (the highest tolerated dose) 1 week before surgery. Results Mean tissue concentrations at surgery were higher in cancer, normal non-injected peritumoral mucosa, and lymph node tissues than in serum or urine, in which there were only trace concentrations. While epigastric pain and histological modifications (inflammation and thickening of the gastric layers) were manifest in patients treated with 75 mg doses in the dose finding session, no clinical signs or symptoms of toxicity were recorded in those administered with 50 mg doses. Conclusions Local administration of D may allow it to reach high concentrations in normal non-injected peritumoral mucosa, and lymph nodes, while simultaneously avoiding significant systemic exposure and toxicity. This procedure could merit further investigation, in view of a possible use of anthracyclines against metastatic diffusion through the lymphatic system in gastric cancer patients who are candidates for gastric resection.

Because of a possible relationship between tamoxifen (T) concentrations and clinical effects, we initiated a preliminary investigation on serum and tissue concentrations of T and its main active metabolites, and 4-hydroxytamoxifen, in women with positive breast cancer estrogen receptor. One hundred forty-eight patients were studied: 80 were admitted for monitoring of therapeutic serum drug concentrations, 22 had tissue concentrations taken at surgery, and 46 patients had uterine mucosa levels measured at diagnostic hysteroscopy. Steady-state serum concentrations were reached after 1 month of continuous treatment, with desmethyltamoxifen being the highest represented derivative from the third week onward. There was no relationship between dose (in mg/kg body weight) and steady-state serum concentrations during therapeutic drug monitoring of patients. The highest tissue concentrations were observed in breast lymph-nodes, cancer tissue, and uterine mucosa. On the basis of these data, we speculate that T and its active metabolites may exert both a defensive role (ie, an obstacle to the diffusion of malignant cells through the local lymphatic system) and a harmful one (induction of uterine malignancies).

Concentrations of tamoxifen and its metabolites were analysed in the endometrium of 23 post-menopausal asymptomatic breast cancer patients who were on chronic tamoxifen therapy. Small endometrial samples were collected during diagnostic hysteroscopy. Analysis of both serum and tissue for these compounds was performed by mass spectrometry. Tamoxifen and its metabolites were far more concentrated in the endometrium than in serum; tamoxifen was also significantly more concentrated in endometrium with hyperplastic changes than in atrophic endometrium. Endometrial polyps of an additional 9 women showed a trend to a lesser concentration of compounds. Increased concentration of tamoxifen compounds could possibly be explained by the avidity of these compounds for oestrogen receptors (ER).

An epiletic patient, suffering from partial complex seizures and hypertension, ingested approximately 42 g of oxcarbazepine (OXC) and an undefined number of tablets containing an association of benazepril and hydrochlorothiazide along with some glasses of wine. Four hours later he was brought to the emergency room. He was stuporous and gradually became unconscious. Therefore he was intubated and, approximately 6 hours after the overdose, transferred to the intensive care unit, where he underwent a 4-hour hemodialysis. Even if this procedure did not accelerate the elimination of the prodrug nor its active metabolite (monohydrocarbazepine), 3 hours after the end of dialysis the patient was fully recovered.