moxifloxacin + cobicistat

This is a combination of two distinct drugs: moxifloxacin, which is an antibacterial medication, and cobicistat, which is a pharmacokinetic enhancer used in HIV treatment. ### Moxifloxacin Moxifloxacin is an antibacterial prescription medicine approved for treating certain bacterial infections, including community-acquired pneumonia, acute worsening of chronic bronchitis, acute sinus infections, plague, and skin and abdominal infections[4]. In HIV patients, it can be used to treat community-acquired pneumonia (which can be an opportunistic infection), disseminated Mycobacterium avium complex (MAC) infection, active tuberculosis, and certain bacterial enteric infections[4]. ### Cobicistat Cobicistat is a CYP3A inhibitor used to increase the systemic exposure of HIV antiretroviral medications like atazanavir or darunavir[1]. It works as a pharmacokinetic enhancer by inhibiting cytochrome P450 3A (CYP3A), which increases the systemic exposure of CYP3A substrates[5]. Unlike ritonavir, cobicistat has no antiretroviral activity of its own[5]. ### Potential Interaction According to the search results, there is a specific note about ciprofloxacin (which is in the same fluoroquinolone class as moxifloxacin) with darunavir/cobicistat, indicating "Do Not Coadminister"[7]. This suggests there may be contraindications or significant interactions between fluoroquinolone antibiotics and cobicistat-boosted regimens. The potential for clinically significant drug interactions in patients taking cobicistat is high due to its potent inhibitory effect on cytochrome CYP 450[8], which could affect the metabolism of moxifloxacin.