Isoniazid and rifampin

You should not use isoniazid and rifampin if you have active liver disease (including hepatitis or cirrhosis), or a history of liver problems caused by taking isoniazid.

Serious and sometimes fatal liver problems may occur during treatment with isoniazid and rifampin or after you stop taking this medication, even months after stopping. The risk of liver problems is highest in adults between the ages of 35 and 65. Your liver function may need to be checked every month while you are taking this medicine.

Call your doctor right away if you have: nausea, upper stomach pain, loss of appetite, and feeling weak or tired.

Avoid drinking alcohol. It may increase your risk of liver damage while you are taking isoniazid and rifampin.

Do not wear soft contact lenses while taking isoniazid and rifampin. Rifampin may turn your tears a red-orange color. This effect could permanently discolor soft contact lenses.

Avoid drinking alcohol. It may increase your risk of liver damage while you are taking isoniazid and rifampin.

Applies to isoniazid / rifampin: oral capsule

General

Doses greater than 600 mg of rifampin given once or twice weekly have resulted in a higher incidence of adverse reactions, including the "flu syndrome" (fever, chills, malaise); hematopoietic reactions (leukopenia, thrombocytopenia, acute hemolytic anemia); shortness of breath; shock; anaphylaxis; renal failure; and cutaneous, gastrointestinal, and hepatic reactions.[Ref]

Cardiovascular

Frequency not reported: Vasculitis

Rifampin:
Frequency not reported: Flushing, decreased blood pressure[Ref]

Dermatologic

Frequency not reported: Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome, Stevens-Johnson syndrome, Toxic Epidermal Necrolysis (TEN), rash

Isoniazid:
Frequency not reported: Acne, exfoliative dermatitis, pemphigus

Rifampin:
Frequency not reported: Erythema multiforme, skin reaction, pruritus, pruritic rash, urticaria, allergic dermatitis, pemphigoid, sweat discoloration, cutaneous reactions[Ref]

Endocrine

Isoniazid:
Frequency not reported: Gynecomastia, hyperglycemia

Rifampin:
Rare (less than 0.1%): Adrenal insufficiency
Frequency not reported: Menstrual disorder/disturbances[Ref]

Gastrointestinal

Frequency not reported: Nausea, vomiting, epigastric distress, diarrhea

Isoniazid:
Frequency not reported: Constipation, dry mouth, pancreatitis

Rifampin:
Frequency not reported: Gastrointestinal disorder, abdominal discomfort, heartburn, flatulence, cramps, pseudomembranous colitis, sore mouth, sore tongue[Ref]

Hematologic

Frequency not reported: Thrombocytopenia, eosinophilia, agranulocytosis, hemolytic anemia

Isoniazid:
Frequency not reported: Anemia, aplastic anemia, lymphadenopathy

Rifampin:
Uncommon (0.1% to 1%): Leukopenia
Rare (less than 0.1%): Disseminated intravascular coagulation
Frequency not reported: Decreased hemoglobin[Ref]

Hepatic

Frequency not reported: Hepatitis, elevated serum transaminases (SGOT, SGPT), bilirubinemia, bilirubinuria, jaundice

Rifampin:
Common (1% to 10%): Elevated alkaline phosphatase
Rare (less than 0.1%): Abnormal liver function, shock-like syndrome with hepatic involvement
Frequency not reported: Hyperbilirubinemia[Ref]

Hypersensitivity

Rifampin:
Rare (less than 0.1%): Anaphylaxis[Ref]

Metabolic

Isoniazid:
Frequency not reported: Pellagra, pyridoxine deficiency, metabolic acidosis

Rifampin:
Frequency not reported: Decreased appetite, anorexia[Ref]

Musculoskeletal

Isoniazid:
Frequency not reported: Systemic lupus erythematosus-like syndrome, rheumatic syndrome

Rifampin:
Rare (less than 0.1%): Myopathy
Frequency not reported: Muscle weakness, bone pain[Ref]

Nervous system

Peripheral neuropathy associated with isoniazid is dose-dependent, most often occurs in malnourished patients and in patients predisposed to neuritis (such as alcoholics and diabetics), and generally follows paresthesias of the hands and feet. The rate is higher in slow acetylators.[Ref]

Isoniazid:
Common (1% to 10%): Peripheral neuropathy
Uncommon (0.1% to 1%): Convulsions, toxic encephalopathy, optic neuritis and atrophy, memory impairment
Frequency not reported: Vertigo, polyneuritis (presenting as paresthesia, muscle weakness, loss of tendon reflexes)

Rifampin:
Frequency not reported: Headache, drowsiness, cerebral hemorrhage, ataxia, dizziness, inability to concentrate, muscular weakness, pains in extremities, generalized numbness[Ref]

Ocular

Rifampin:
Frequency not reported: Tear discoloration, visual disturbances, conjunctivitis[Ref]

Other

Frequency not reported: Fever

Isoniazid:
Frequency not reported: Anti-nuclear antibodies

Rifampin:
Frequency not reported: Influenza-like syndrome, post-partum hemorrhage, fetal-maternal hemorrhage, porphyria, edema, fatigue, facial edema, edema of the extremities, shock[Ref]

Psychiatric

Isoniazid:
Frequency not reported: Toxic psychosis

Rifampin:
Frequency not reported: Psychotic disorder/psychoses, mental confusion, behavioral changes[Ref]

Renal

Rifampin:
Rare (less than 0.1%): Hemolysis, hemoglobinuria, hematuria, interstitial nephritis, acute tubular necrosis, renal insufficiency, acute renal failure
Frequency not reported: Acute kidney injury, chromaturia, increased blood creatinine, elevated BUN, elevated serum uric acid[Ref]

Respiratory

Rifampin:
Frequency not reported: Dyspnea, wheezing, discolored sputum, shortness of breath[Ref]

Some side effects of isoniazid / rifampin may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Data not available

Data not available

Pyridoxine, 50 mg orally once a day, may be administered concurrently to prevent the occurrence of peripheral neuropathy caused by the isoniazid component. Concomitant pyridoxine is recommended in malnourished patients, patients predisposed to neuropathy (such as diabetics), and adolescents.

Isoniazid-rifampin should only be used in patients previously titrated on the individual components and in which the therapeutic effectiveness of the fixed dosage has been confirmed.

This combination product should not be used for the initial treatment of tuberculosis. It should only be used after the recommended initial 2 month therapy with isoniazid plus rifampin plus pyrazinamide. The isoniazid-rifampin fixed-dosage combination is not recommended for preventive therapy and it is not indicated for the treatment of meningococcal infections or to eliminate meningococci from the nasopharynx in asymptomatic carriers of Neisseria meningitidis.