Generic Name and Formulations:
Rifampin 300mg, isoniazid 150mg; caps.
Indications for RIFAMATE:
Susceptible pulmonary tuberculosis. Not for initial therapy.
Take 1 hour before or 2 hours after a meal. 2 caps once daily. Malnourished, predisposed to neuropathy (eg, diabetes), adolescents: concomitant Vit. B6 recommended.
Previous isoniazid-associated hepatic injury. Severe adverse reactions to isoniazid (eg, drug fever, chills, arthritis, acute liver disease). Drug-induced hepatitis.
Increased risk of severe or fatal hepatitis; monitor, discontinue if signs of hepatic damage detected. Acute hepatic disease: do not treat. Chronic liver disease. Perform LFTs prior to therapy, then periodically. Severe renal dysfunction. Not recommended for intermittent therapy (risk of renal hypersensitivity reactions; rare). May stain body secretions and contact lenses. Perform eye exams if visual symptoms occur. Neonates/newborns of rifamate-treated mothers (monitor for untoward effects). Pregnancy (teratogenic potential). Nursing mothers.
Concomitant hepatotoxic agents: may cause fatal liver dysfunction. Concomitant alcohol may be associated with higher incidence of isoniazid hepatitis. Monitor prothrombin time with concomitant anticoagulants. May potentiate phenytoin (adjust dose). May antagonize oral contraceptives, methadone, oral hypoglycemics, digoxin, quinidine, disopyramide, dapsone, corticosteroids. May inhibit assays for serum folate and Vit. B12 (consider alternative methods).
Rifamycin + isonicotinic acid.
Headache, drowsiness, fatigue, ataxia, dizziness, inability to concentrate, mental confusion, visual disturbances, muscular weakness, pain in extremities, generalized numbness, peripheral neuropathy (esp. in slow inactivators), GI disturbances, abnormal LFTs, hepatitis (may be severe or fatal), bilirubinemia, jaundice, elevated BUN and serum uric acid, blood dyscrasias, pruritus, rash, fever, menstrual disturbances, pyridoxine deficiency, hyperglycemia, rheumatic syndrome, systemic lupus erythematosus-like syndrome, others.