Pharmacokinetics of lower doses of saquinavir soft-gel caps (800 and 1200 mg twice daily) boosted with itraconazole in HIV-1-positive patients

Abstract

Objective: The pharmacokinetics of 800 mg and 1200 mg of saquinavir soft-gel caps (SQV-SGC) twice daily plus 100 mg itraconazole once daily were compared to 1400 mg SQV-SGC twice daily without itraconazole. Methods: The pharmacokinetics of SQV were determined in 17 randomly selected patients on 1400 mg twice daily SQV-SGC without itraconazole and after 2 weeks with lower SQV-SGC doses plus itraconazole. SQV plasma concentrations were determined by HPLC. Pharmacokinetic parameters were calculated by a non-compartmental model. Results: Median (+IQR) area under plasma concentration-versus-time curve (AUC0-12h) were 3.33 (1.96-7.34), 4.29 (3.14-7.67) and 4.07 (2.76-4.49) mg/l.h for SQV 1400 mg without itraconazole, SQV 1200 mg with itraconazole and SQV 800 mg with itraconazole, respectively. These differences were not statistically significant. The median Cmin was above the proposed minimum effective concentration of 0.05 mg/l for all three regimens. Conclusion: SQV-SGC 800 mg or 1200 mg twice daily boosted with 100 mg of itraconazole once daily resulted in adequate SQV pharmacokinetics not significantly different from SQV-SGC 1400 mg twice daily.