tenofovir disoproxil fumarate + emtricitabine + efavirenz + rifampicin + isoniazid

This is a five-drug combination consisting of three antiretroviral agents—tenofovir disoproxil fumarate, emtricitabine, and efavirenz—and two anti-tuberculosis drugs—rifampicin and isoniazid. The antiretrovirals are used for the treatment of HIV-1 infection, while rifampicin and isoniazid are first-line agents for the treatment and prevention of tuberculosis (TB). Tenofovir disoproxil fumarate is a nucleotide reverse transcriptase inhibitor (NRTI) that inhibits HIV-1 reverse transcriptase by competing with deoxyadenosine 5'-triphosphate and causing DNA chain termination. Emtricitabine is a nucleoside reverse transcriptase inhibitor (NRTI) that also inhibits HIV-1 reverse transcriptase by competing with deoxycytidine 5'-triphosphate. Efavirenz is a non-nucleoside reverse transcriptase inhibitor (NNRTI) that noncompetitively inhibits HIV-1 reverse transcriptase. Rifampicin acts as an RNA polymerase inhibitor in Mycobacterium tuberculosis, blocking bacterial transcription. Isoniazid inhibits mycolic acid synthesis in mycobacterial cell walls, leading to cell death. This combination may be used in patients co-infected with HIV and TB to provide simultaneous therapy for both infections.