Medicine is knowledge

Pulmonary tuberculosis (TB) is treated with a combination of antibiotics to prevent the development of drug resistance and ensure effective eradication of the Mycobacterium tuberculosis bacteria. The treatment regimen, including the types of drugs, dosages, and duration, can vary based on factors such as the patient's age, weight, and presence of drug-resistant TB. Here’s an overview of the standard drug doses used in the treatment of pulmonary tuberculosis: ### First-Line Drugs 1. Isoniazid (INH) - Adults: 5 mg/kg (usually 300 mg) daily. - Children: 10-15 mg/kg (maximum 300 mg) daily. - Pyridoxine (Vitamin B6) is often co-administered to prevent peripheral neuropathy, especially in those at risk (e.g., pregnant women, malnourished individuals, patients with diabetes or HIV). 2. Rifampin (RIF) - Adults: 10 mg/kg (usually 600 mg) daily. - Children: 10-20 mg/kg (maximum 600 mg) daily. 3. Ethambutol (EMB) - Adults: 15-20 mg/kg daily. - Children: 15-25 mg/kg daily (maximum 2.5 g/day). 4. Pyrazinamide (PZA) - Adults: 20-25 mg/kg daily. - Children: 15-30 mg/kg daily (maximum 2 g/day). ### Treatment Phases 1. Intensive Phase - Duration: Typically the first 2 months. - Drugs: Isoniazid, Rifampin, Pyrazinamide, and Ethambutol (HRZE). 2. Continuation Phase - Duration: Usually 4 months but can be extended based on specific patient factors. - Drugs: Isoniazid and Rifampin (HR). ### Treatment for Drug-Resistant TB - Multidrug-resistant TB (MDR-TB): Requires a longer treatment duration (often 18-24 months) and involves second-line drugs. - Common second-line drugs: - Fluoroquinolones (e.g., levofloxacin, moxifloxacin). - Injectable agents (e.g., amikacin, capreomycin). - Other oral agents (e.g., bedaquiline, linezolid, clofazimine). ### Special Populations - Pregnancy: Generally, the standard regimen can be used, but ethambutol and pyrazinamide are preferred. Streptomycin is avoided due to potential ototoxicity to the fetus. - HIV Coinfection: The treatment is similar, but there are significant drug-drug interactions with antiretroviral therapy (ART) that need to be managed carefully. - Children: The dosages are weight-based, and ethambutol is used with caution due to concerns about optic neuritis. ### Monitoring and Adherence - Directly Observed Therapy (DOT) is often recommended to ensure adherence and monitor side effects. - Liver Function Tests (LFTs): Regular monitoring is essential, especially when using isoniazid and pyrazinamide due to the risk of hepatotoxicity. - Vision Tests: For patients on ethambutol, regular vision tests are recommended to detect optic neuritis early. ### Side Effects and Management - Isoniazid: Hepatitis, peripheral neuropathy (prevented with pyridoxine). - Rifampin: Hepatitis, thrombocytopenia, red-orange discoloration of body fluids. - Ethambutol: Optic neuritis (requires baseline and periodic eye exams). - Pyrazinamide: Hepatitis, hyperuricemia (can lead to gout). This standard treatment regimen is highly effective when adhered to properly, but patients require careful monitoring to manage side effects and ensure completion of the therapy.

Photo from Bhaskar

First Aid Clinical Algorithms for the USMLE Step 2 CK 2024 @MedicalBooksStoreA @MedicalBooksStoress @Medical_Books_Storess