Simultaneous determination of nontricyclic antidepressants in human plasma by solid-phase microextraction and liquid chromatography (SPME-LC).

A sensitive, selective, and reproducible solid-phase microextraction and liquid chromatographic (SPME-LC) method for simultaneous determination of mirtazapine, citalopram, paroxetine, fluoxetine, and sertraline in human plasma was developed, validated, and further applied to analyze plasma samples obtained from patients with depression. Important factors in the optimization of SPME efficiency are discussed, including the fiber coating, extraction time, pH, ionic strength, influence of plasma proteins, and desorption conditions. The limit of quantitation of the nontricyclic antidepressants in plasma varied from 25 to 50 ng/mL with a coefficient of variation lower than 5%. The response of the SPME-LC method for most of the drugs was linear over a dynamic range of 50 to 500 ng/mL, with all of them having correlation coefficients greater than 0.9970. The performance of the SPME-LC method allowed the nontricyclic antidepressants analyses in therapeutic levels.

Reliable HPLC method for therapeutic drug monitoring of frequently prescribed tricyclic and nontricyclic antidepressants.

A new high-performance liquid chromatography method is presented for the determination of 10 frequently prescribed tricyclic and nontricyclic antidepressants: imipramine, amitriptyline, clomipramine, fluoxetine, sertraline, paroxetine, citalopram, mirtazapine, moclobemide and duloxetine. The simple and accurate sample preparation step, consisted of liquid:liquid extraction with recoveries ranging between 72% and 86%, except for moclobemide (59%). Separation was obtained using a reverse phase Select B column under isocratic conditions with UV detection (230 nm). The mobile phase consisted of 35% of a mixture of acetonitrile/methanol (92:8, v/v) and 65% of 0.25 mol L(-1) sodium acetate buffer, pH 4.5. The standard curves were linear over a working range of 2.5-1000 ng mL(-1) for moclobemide, 5-2000 ng mL(-1) for citalopram, duloxetine, fluoxetine, 10-2000 ng mL(-1) for sertraline, imipramine, paroxetine, mirtazapine and clomipramine. The intra-assay and inter-assay precision and accuracy were studied at three concentrations (50, 200, and 500 ng mL(-1)). The intra-assay coefficients of variation (CVs) for all compounds were less than 8.8%, and all inter-CVs were less than 10%. Limits of quantification were 2.5 ng mL(-1) for moclobemide, 5 ng mL(-1) for citalopram, duloxetine and amitriptyline, and 10 ng mL(-1) for mirtazapine, paroxetine, imipramine, fluoxetine, sertraline, and clomipramine. No interference of the drugs normally associated with antidepressants was observed. The method has been successfully applied to the analysis of real samples, for the drug monitoring of ten frequently prescribed tricyclic and non-tricyclic antidepressant drugs.

Biochemical and hematological side effects of clofazimine in leprosy patients.

Gastrointestinal toxicity and red skin discoloration were the major side effects observed in leprosy patients undergoing long-term treatment with clofazimine (CFZ). Hematological and biochemical alterations have been cited among other side effects; however, their real magnitude and clinical significance at the doses currently employed in therapy have not been sufficiently documented. We therefore investigated the correlation between CFZ plasma concentration and biochemical (transaminases, bilirubins, alkaline phosphatase, gamma-glutamyltransferase, amylase, urea, creatinine, and potassium plasma levels) as well as hematological changes blood and reticulocyte counts, osmotic fragility, detection of Heinz bodies and methemoglobinemia (MHM), following in two regimes of treatment: CFZ as a single drug and CFZ as part of multidrug (MDT) therapy, in combination with dapsone and rifampicin. MHM and hemolytic anemia were detected in the MDT group only. Eosinophilia was found in patients of either group. Determination of hepatic, pancreatic and renal biochemical parameters showed rare, occasional changes of apparently no clinical significance. We conclude that CFZ is a generally well tolerated and safe drug when given as a daily dose of 50mg, which is currently used in leprosy patients.