Custom Search


Tuesday 03 April 2007

Effect of efavirenz on the pharmacokinetics of ketoconazole in HIV-infected patients.

By: Sriwiriyajan S, Mahatthanatrakul W, Ridtitid W, Jaruratanasirikul S.

Eur J Clin Pharmacol 2007 May;63(5):479-83

OBJECTIVE: To investigate the effect of efavirenz on the ketoconazole pharmacokinetics in HIV-infected patients. METHODS: Twelve HIV-infected patients were assigned into a one-sequence, two-period pharmacokinetic interaction study. In phase one, the patients received 400 mg of ketoconazole as a single oral dose on day 1; in phase two, they received 600 mg of efavirenz once daily in combination with 150 mg of lamivudine and 30 or 40 mg of stavudine twice daily on days 2 to 16. On day 16, 400 mg of ketoconazole was added to the regimen as a single oral dose. Ketoconazole pharmacokinetics were studied on days 1 and 16. RESULTS: Pretreatment with efavirenz significantly increased the clearance of ketoconazole by 201%. C(max) and AUC(0-24) were significantly decreased by 44 and 72%, respectively. The T ((1/2)) was significantly shorter by 58%. CONCLUSION: Efavirenz has a strong inducing effect on the metabolism of ketoconazole.

Use of this site is subject to the following terms of use