RESUMO
Nefazodone is a potent and selective inhibitor of cytochrome P450 3A4 (CYP3A4), an enzyme pathway responsible for the biotransformation of a number of steroid compounds. The potential therefore exists that nefazodone inhibits the disposition of methylprednisolone. In this open label, repeated measures study, the effect of 9 days of nefazodone administration on the pharmacokinetic disposition of a single 0.6 mg/kg intravenous dose of methylprednisolone was assessed. Additionally the effect of concomitant nefazodone use on duration of cortisol suppression after methylprednisolone administration was assessed. Eight healthy volunteers completed the study. Following nefazodone administration, the mean (+/-SD) area under the methylprednisolone concentration-time curve was significantly higher (1393 +/- 343 vs. 2966 +/- 928 ug*h/L; P < 0.005), apparent clearance was lower (28.7 +/- 7.2 vs. 14.6 +/- 7.8 L/h; P < 0.02) and the terminal elimination half-life was longer (2.28 +/- 0.49 vs. 3.32 +/- 0.95 hours; P < 0.02). The duration of cortisol suppression after methylprednisolone administration was longer (> or =32 vs. 23.3 +/- 3.43 hours) during nefazodone administration.
Assuntos
Córtex Suprarrenal/efeitos dos fármacos , Antidepressivos de Segunda Geração/farmacologia , Inibidores das Enzimas do Citocromo P-450 , Glucocorticoides/farmacocinética , Metilprednisolona/farmacocinética , Triazóis/farmacologia , Adulto , Citocromo P-450 CYP3A , Interações Medicamentosas , Feminino , Humanos , Hidrocortisona/sangue , Masculino , Piperazinas , Valores de ReferênciaRESUMO
OBJECTIVE: This randomized, double-blind, placebo-controlled study evaluated the efficacy and tolerability of bupropion sustained-release (bupropion SR) in reducing weight and depressive symptoms in obese adults. RESEARCH METHODS AND PROCEDURES: Obese adults (body mass index, 30 to 44 kg/m(2)) not currently meeting criteria for major depression but with depressive symptoms (Beck Depression Inventory score 10-30) received bupropion SR 300 mg/d or placebo for 26 weeks with a 500 kcal/d-deficit diet. Patients who lost <5% of baseline weight at week 12 had bupropion SR dosage or placebo increased to 400 mg/d in a blinded fashion. RESULTS: The bupropion SR group (n = 193) lost an average of 4.4 kg (4.6% of baseline weight) vs. 1.7 kg (1.8% of baseline weight) on placebo (n = 191, p < 0.001, last-observation-carried-forward analysis). More patients in the bupropion SR group than in the placebo group (40% vs. 16% of intent-to-treat sample, 50% vs. 28% of completers, respectively) lost at least 5% of baseline weight (p < 0.05 at week 4, p < 0.001 at weeks 6 to 26). The percentage of patients reporting > or =50% decrease in depressive symptoms did not differ between groups, but depressive symptoms improved more with bupropion SR than with placebo among patients with a history of major depression (p < 0.05, weeks 4 to 26). In the sample as a whole, improvement in depressive symptoms was related to weight loss of > or =5% regardless of treatment (p < 0.0001). Bupropion SR was well-tolerated. DISCUSSION: Bupropion SR in combination with a 500 kcal/d-deficit diet facilitated weight loss. Weight loss of > or =5% may improve mood in obese patients with depressive symptoms.