Category: catabolism
Mycobacterial pharmacology is its own world — the waxy mycolic-acid cell envelope is impermeable to most antibiotics. The standard RIPE regimen for active TB: rifampin (RNA polymerase β-subunit, rpoB), isoniazid (KatG-activated → mycolic acid synthesis InhA inhibition), pyrazinamide (acidic-pH-dependent activation → membrane disruption), ethambutol (arabinosyl transferase, arabinogalactan synthesis). Rifampin is also a profound CYP3A4 + P-gp inducer (DDI perpetrator hot spot — authored Wave 2a v1.1 for buprenorphine + oxycodone). Rifabutin is a rifampin analog with somewhat less induction (used in HIV co-treatment when PI/INSTI DDIs are limiting). Rifaximin (gut-only rifamycin) is non-systemic and used for hepatic encephalopathy + traveler's diarrhea — local-acting despite the rifamycin class membership.