Antiretroviral therapy for HIV-associated tuberculosis

Tuberculosis (TB) remains an important problem in HIV-infected patients worldwide. HIV-related immunosuppression modifies the clinical presentation of TB, resulting in atypical signs and symptoms, and an increasing number of smear-negative pulmonary and extrapulmonary TB cases. HIV-associated TB patients also have increased morbidity and mortality due to TB and other HIV related diseases. The appropriate management of HIV-associated TB remains extremely challenging due to diagnostic difficulties, adherence concerns, the overlapping side effect profiles of anti-TB and antiretrovirals (ARV), the complexity of drug-drug interactions secondary to potent induction of cytochrome P450 enzymes by rifampin, and the occurrence of the immune reconstitution inflammatory syndrome (IRIS) after initiation of ARV Highly active antiretroviral therapy (HAART) improves the clinical outcome of both HIV and TB. However, the optimal time to start HAART remains unknown. HAART should be started early in 2-8 weeks in the context of severe immune suppression. Efavirenz-based HAART is preferred. However, HIV-associated TB patients who are unable to use non-nucleoside reverse transcriptase inhibitors (NNRTI) such as NNRTI resistant virus or NNRTI intolerance are of particular concern. Replacing rifampin with rifabutin, which does not significantly affect ARV concentrations, is recommended.