Anti-tuberculosis drugs

First-line drugs Isoniazid (INH or H) Rifampin (RMP or R) Ethambutol (EMB or E) Pyrazinamide (PZA or Z)

Second-line drugs 當出現 drug intolerance or resistance to first- line therapy 時使用 – Cycloserine – Ethionamide – p-Aminosalicylic acid – Streptomycin – Amikacin – Capreomycin

Recommended Regimens Initial phase – 2 months – INH, RIF, PZA, and EMB Continuation phase – 4 months: in most cases – 7 months: sputum culture remains positive at two months of treatment did not receive PZA during the initial phase of treatment – INH and RIF

Directly Observed Therapy (DOT) A lower rate of primary drug resistance : 6.7 vs. 13 % A lower rate of acquired drug resistance : 2.1 vs. 14 % A lower relapse rate : 5.5 vs % Fewer relapses with resistant organisms : 0.9 vs. 6.2 %

Side-effects Multidrug-resistant tuberculosis (MDR-TB) – 定義 : 對 first-line antituberculosis drugs 有抗藥性， 又依嚴重度分為 drug-resistant tuberculosis Multidrug-resistant tuberculosis Extensively drug-resistant tuberculosis – 治療須至少使用四種針對 most prevalent drug- resistant strains 有效的藥

Side-effects Hepatitis (INH,RIF,PZA) – Age-dependent: 年輕人少見 – Toxicity is increased by daily alcohol use Peripheral neuropathy (INH) – Increased risk: nutritional deficiency, diabetes, HIV infection, renal failure, alcoholism, pregnant and breastfeeding women – Pyridoxine 可用來預防此副作用

Side-effects Increased hepatic clearance (RIF) – 因為其 induces hepatic microsomal enzymes – 造成 decrease the effectiveness of a number of drugs Hyperuricemia (PZA) – 因為 decreased renal excretion optic neuritis (EMB) – 通常表現為 change in visual acuity or red-green color blindness – reversible in most patients – Intermittent dosing may decrease the risk