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Isoniazid / Pyrazinamide / Rifampin Side Effects

Medically reviewed by Drugs.com. Last updated on Aug 26, 2024.

Applies to isoniazid / pyrazinamide / rifampin: oral tablet.

Important warnings This medicine can cause some serious health issues

  • This drug may cause very bad and sometimes deadly liver problems like hepatitis.

    Call your doctor right away if you have signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.

  • The chance of liver problems is higher the older you are.

    The chance may also be raised by drinking alcohol every day, long-term liver problems, or injection drug use.

    The chance of liver problems may also be raised in women, mainly women who are black or Hispanic or who have just had a baby.

    Most of the time, liver problems caused by this drug happen within the first 3 months of care, but they can happen at any time.

    Most of the time, liver function has gone back to normal but sometimes it has not.

    Blood work will need to be done before starting this drug and while taking it.

    If you have questions, talk with the doctor.

  • Have blood work checked as you have been told by the doctor.

    Talk with the doctor.

  • If you have active liver disease, talk with your doctor.

    This drug may not be right for you.

Serious side effects

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

Other side effects

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

For healthcare professionals

Applies to isoniazid / pyrazinamide / rifampin: oral tablet.

General

Isoniazid: The most frequently reported side effects are those affecting the nervous system and liver.

Pyrazinamide: The most frequently reported side effects are those affecting the liver.

Rifampin: The most frequently reported side effects are thrombocytopenia and those affecting the nervous system.[Ref]

Hepatic

Isoniazid:

Pyrazinamide:

Rifampin:

Common prodromal symptoms of severe/fatal hepatitis included anorexia, fatigue, malaise, nausea, vomiting, and weakness.

Mild and transient transaminase elevations usually occurred in the first 4 to 6 months of treatment with isoniazid, and enzyme levels typically returned to normal without patients needing to discontinue treatment.

Progressive liver damage was age-related, and more commonly occurred in patients over 50 years of age.[Ref]

Dermatologic

Isoniazid:

Pyrazinamide:

Rifampin:

Nervous system

Isoniazid:

Rifampin:

Cerebral hemorrhage and fatal cerebral hemorrhage have occurred in patients who have continued or resumed treatment with rifampin after the appearance of purpura.

Polyneuritis associated with isoniazid (e.g., muscle weakness, loss of tendon reflexes, paresthesia) was unlikely to occur at the recommended daily dose of this combination drug.

High doses of isoniazid have resulted in convulsions and toxic encephalopathy.[Ref]

Gastrointestinal

Isoniazid:

Pyrazinamide:

Rifampin:

Cardiovascular

Isoniazid:

Rifampin:

Other

Isoniazid:

Pyrazinamide:

Rifampin:

Musculoskeletal

Isoniazid:

Pyrazinamide:

Rifampin:

Respiratory

Rifampin:

Psychiatric

Isoniazid:

Rifampin:

Local

Hematologic

Isoniazid:

Pyrazinamide:

Rifampin:

Thrombocytopenia with/without purpura usually occurred with intermittent rifampin treatment or upon resumption of interrupted treatment, but was typically reversible if the drug was discontinued as soon as purpura occurred.[Ref]

Hypersensitivity

Isoniazid:

Pyrazinamide:

Rifampin:

Renal

Pyrazinamide:

Rifampin:

Acute renal failure, acute tubular necrosis, hematuria, hemoglobinuria, hemolysis, interstitial nephritis, and renal insufficiency are considered hypersensitivity reactions to rifampin, and usually occurred during intermittent treatment or upon resumption of treatment following intentional/accidental interruption of a daily regimen; these reactions were reversible when this drug was discontinued and appropriate therapy was given.[Ref]

Genitourinary

Isoniazid:

Pyrazinamide:

Rifampin:

Metabolic

Isoniazid:

Pyrazinamide:

Rifampin:

Endocrine

Isoniazid:

Rifampin:

Adrenal insufficiency occurred in patients with compromised adrenal function receiving rifampin.[Ref]

Immunologic

Isoniazid:

Pyrazinamide:

Rifampin:

Flu syndrome usually occurred in patients taking intermittent rifampin regimens; however, this side effect has also occurred in patients taking rifampin irregularly and in those resuming treatment after a drug-free interval.[Ref]

Ocular

Isoniazid:

Rifampin:

Oncologic

Pyrazinamide:

References

1. (2001) "Product Information. Rifater (isoniazid / pyrazinamide / rifampin)." SmithKline Beecham

2. Cerner Multum, Inc. "UK Summary of Product Characteristics."

Further information

Isoniazid/pyrazinamide/rifampin side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.