Altered Pharmacokinetics and Delayed Sputum Conversion in Tuberculosis Patients Co-Infected With HIV.

Area of Science:

• Pharmacokinetics and clinical outcomes in infectious diseases.
• Tuberculosis and HIV co-infection research.

Background:

• HIV co-infection significantly impacts host responses and tuberculosis (TB) treatment pharmacokinetics (PK).
• Understanding these interactions is crucial for optimizing TB treatment in co-infected individuals.

Purpose of the Study:

• To assess the PK of first-line anti-TB drugs in patients with and without HIV co-infection.
• To evaluate the association between HIV status and clinical outcomes, including sputum conversion.

Main Methods:

• Prospective observational study of 61 adults with sputum-positive pulmonary TB (24 HIV-positive, 37 HIV-negative).
• PK assessments for standard anti-TB therapy at Day 1 and Week 6.
• Monitoring of clinical outcomes, sputum conversion, and adverse events; ART initiated around Day 21 for HIV-positive participants.

Main Results:

• HIV co-infection was associated with reduced early clearance of isoniazid and ethambutol, with differences resolving by Week 6.
• HIV-positive status (OR=14.25) and higher baseline sputum bacillary load (OR=3.92) independently predicted delayed sputum conversion (>8 weeks).
• ART initiation did not significantly impact these PK differences by Week 6.

Conclusions:

• HIV co-infection is linked to early alterations in isoniazid and ethambutol PK, but clinical significance remains uncertain.
• HIV status and high bacillary load are associated with delayed sputum conversion.
• Current data do not support routine anti-TB drug dose adjustments in TB-HIV co-infected patients; further exposure-response studies are warranted.