Pharmacokinetics and 48-week efficacy of nevirapine: 400 mg versus 600 mg per day in HIV-tuberculosis coinfection receiving rifampicin.

BACKGROUND: We aim here to determine the appropriate dose of nevirapine (NVP) in Thai HIV-tuberculosis (TB)-coinfected patients receiving rifampicin. METHODS: Thirty-two HIV-infected adults with CD4+ T-cell counts <200 cells/mm3 and active TB, receiving rifampicin for 2-6 weeks were randomized to receive either NVP 400 mg (NVP400) or 600 mg (NVP600) per day plus two nucleoside reverse transcriptase inhibitors; a 2-week NVP lead-in was performed at 200 mg once daily (OD) and 200 mg twice daily, respectively. Plasma NVP levels were determined at weeks 2, 4 and 12. Twelve-hour pharmacokinetics (PK) were obtained (n=20) at week 4. RESULTS: Baseline body weight was comparable. There were more patients with NVP plasma concentration at 12 h (C12) <3.1 mg/l at week 2 in NVP400 than in NVP600 (79% versus 19%, respectively; P=0.002). However, the proportions were comparable at weeks 4 and 12. From week 4, 12 h PK studies showed that NVP400 had lower median NVP area under the plasma concentration-0-12 h (AUC0-12 h, maximum concentration in plasma (Cmax) and C12 than NVP600 (P<0.05). Four patients in NVP600 developed NVP hypersensitivity. At week 48, the median CD4+ T-cell count rise and proportion with viral load