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Rifabutin in Disseminated MAC — SCE Infectious Diseases MCQ

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ModerateHIV MedicineRifabutin in Disseminated MACSCE Infectious Diseases

A 30-year-old man with HIV (CD4 50, not on ART) is diagnosed with disseminated Mycobacterium avium complex. He is started on Clarithromycin 500 mg BD plus Ethambutol 15 mg/kg daily. His team asks about adding a third agent. What is the role of Rifabutin?

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Correct answer: A — Rifabutin may be added as a third agent for severe or disseminated MAC — it provides additive antimycobacterial activity but adds drug interaction complexity

For disseminated MAC in HIV, the core regimen is a macrolide (Clarithromycin preferred over Azithromycin for treatment — Azithromycin is used for prophylaxis) plus Ethambutol. Rifabutin 300 mg daily may be added as a third agent for severe disease, high mycobacterial burden, or if response to dual therapy is suboptimal. Rifabutin is preferred over Rifampicin in HIV due to fewer drug interactions with ART (though dose adjustments are still needed with PIs and Cobicistat). ART should be started within 2 weeks of MAC treatment initiation.

Reference: BHIVA 2022 – OI guidelines; BTS 2017 – NTM; ATS/IDSA 2020