Background: Reports suggest that antituberculosis drugs are malabsorbed in patients with advanced HIV disease.
Objective: To evaluate the pharmacokinetics of antituberculosis agents in HIV-seropositive patients at different stages of disease.
Design: Parallel study.
Setting: Two hospital outpatient clinics.
Participants: 12 healthy volunteers, 12 patients with asymptomatic HIV disease, 12 patients with symptomatic HIV disease, and 12 patients with symptomatic HIV disease and diarrhea.
Measurements: Drug plasma concentrations were measured over 24 hours on day 4 of concurrent therapy.
Intervention: Oral isoniazid (300 mg/d), rifampin (600 mg/d), pyrazinamide (1000 mg/d), and ethambutol (1000 mg/d).
Results: Reduced total drug exposure to rifampin and pyrazinamide was associated with D-xylose malabsorption in persons with HIV infection or AIDS. Peak drug exposure to isoniazid was lower in patients with diarrhea.
Conclusions: Reduced total drug exposure may be related to malabsorption in persons with HIV infection or AIDS.