Generic Name and Formulations:
Rifampin 120mg, isoniazid 50mg, pyrazinamide 300mg; tabs.
Indications for RIFATER:
Initial phase of the short-course (2 months) treatment of susceptible pulmonary tuberculosis.
Take 1hr before or 2hrs after a meal with glass of water. ≥15yrs: take as single daily dose. ≤44kg: 4 tabs. 45–54kg: 5 tabs. ≥55kg: 6 tabs. Malnourished, predisposed to neuropathy (eg, alcoholics, diabetes), adolescents: concomitant Vit. B6 recommended. Following initial phase, treatment should be continued with rifampin and isoniazid for at least 4 months or longer if sputum or culture positive, if resistant organisms are present, or HIV positive.
<15yrs: not established.
Concomitant ritonavir-boosted saquinavir (increased risk of severe hepatotoxicity). Concomitant atazanavir, darunavir, fosamprenavir, saquinavir, tipranavir. Rifamycin hypersensitivity. Severe hepatic damage. Severe adverse reactions to isoniazid (eg, drug fever, chills, arthritis). Acute liver disease of any etiology. Acute gout.
Increased risk of severe or fatal hepatitis; monitor, discontinue if signs of hepatic damage detected. Discontinue if hepatotoxicity or hyperuricemia accompanied by an acute gouty arthritis develops. Chronic liver disease. Alcohol abusers. Severe renal dysfunction; monitor. Diabetes. Not recommended for intermittent therapy (risk of renal hypersensitivity reactions; rare). Monitor for skin or hypersensitivity reactions (eg, SJS, TEN, DRESS); discontinue if occur. May stain teeth, body secretions, and contact lenses. Obtain baseline LFTs, bilirubin, serum creatinine, CBC, platelets, blood uric acid; follow-up monthly. If hepatic impaired: monitor liver function (esp. SGPT/SGOT) prior to therapy and then every 2–4 weeks during. Perform eye exams prior to treatment, then periodically. Elderly. Pregnancy (Cat.C). Nursing mothers: not recommended.
See Contraindications. Concomitant hepatotoxic agents: may cause fatal liver dysfunction. Concomitant alcohol may be associated with higher incidence of isoniazid hepatitis. Avoid tyramine- and histamine-containing foods, halothane. Monitor prothrombin time with concomitant anticoagulants. May potentiate anticonvulsants (eg, phenytoin), benzodiazepines, haloperidol, ketoconazole, theophylline, warfarin; adjust dose. May antagonize anticonvulsants, digoxin, antiarrhythmics, oral anticoagulants, azole antifungals, barbiturates, β-blockers, calcium channel blockers, chloramphenicol, clarithromycin, fluoroquinolones, cyclosporine, cardiac glycosides, clofibrate, diazepam, doxycycline, haloperidol, levothyroxine, oral or systemic hormonal contraceptives (consider nonhormonal methods), methadone, oral hypoglycemics, dapsone, corticosteroids, narcotic analgesics, progestins, quinine, tacrolimus, theophylline, tricyclic antidepressants, zidovudine, atovaquone, enalapril, sulfasalazine. May be potentiated by atovaquone, probenecid, cotrimoxazole, para-aminosalicylic acid. May be antagonized by ketoconazole. CNS effects may be exaggerated with meperidine, cycloserine, disulfiram. Excess catecholamine stimulation or lack of levodopa effect with concomitant levodopa. Monitor renal function with concomitant enflurane. May inhibit diamine oxidase. May cause false (+) urine tests for opiates. May inhibit assays for serum folate and Vit. B12 (consider alternative methods). May interfere with Acetest and Ketostix. Separate from antacids by at least 1 hour.
Rifamycin + isonicotinic acid + nicotinamide analogue.
Rash (may be severe), pruritus, nausea, vomiting, diarrhea, digestive pain, chest tightness/pain, cough, hemoptysis, palpitation, arthralgia, phlebitis, leg edema/paresthesia, sweating, headache, insomnia, anxiety, tinnitus, vertigo, fever; hepatitis, hypersensitivity reactions (may be severe), hyperuricemia, discoloration.