Chapter 19: Anti-TB and Anti-Leprosy Antibiotics

The foundation of tuberculosis management involves simultaneously administering multiple agents, often through supervised administration protocols that ensure medication adherence and treatment completion. Isoniazid functions as a cornerstone first-line agent by inhibiting the synthesis of mycolic acids essential to bacterial cell wall integrity, though its metabolism varies significantly between individuals classified as rapid or slow processors based on genetic factors, creating implications for appropriate dosing. This drug carries risks of liver damage and neurological complications preventable through supplementation with vitamin B6. Rifampin operates through a distinct mechanism targeting bacterial RNA synthesis machinery while simultaneously inducing hepatic enzyme systems that accelerate the breakdown of numerous other medications, necessitating careful consideration when patients require concurrent therapies. Alternative rifamycins offer advantages in specific clinical scenarios where drug interactions present barriers to effective treatment. Pyrazinamide exhibits enhanced antimicrobial activity in the acidic microenvironments found within infected cells, while ethambutol disrupts the synthesis of carbohydrate polymers comprising the bacterial envelope and demands ophthalmologic monitoring due to potential vision complications. Streptomycin provides an injectable option from the aminoglycoside class suitable for inclusion in certain treatment protocols. The chapter distinguishes treatment approaches for active disease versus preventive therapy in individuals demonstrating immune reactivity without clinical disease manifestations. Anti-leprosy treatment focuses on sulfone agents that interfere with folate metabolism, coupled with phenothiazine dyes that interact with genetic material and cause characteristic pigmentation changes. A critical concern involves hemolytic complications in patients with specific glucose metabolism deficiencies. The text addresses management of immunologic complications arising during leprosy therapy, including inflammatory nodular skin lesions treated with anti-inflammatory medications or immunomodulatory agents.