Isoniazid/Rifampin Interactions
This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.
Medical warning:
Moderate. These medicines may cause some risk when taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
When these two medicines are taken together, your body may not process isoniazid properly.
What might happen:
This medication combination is often used together. However, there is a small risk that they could damage to your liver. Drinking alcohol while you are taking these medications may further increase the risk for liver damage.
What you should do about this interaction:
Let your healthcare professional (e.g. doctor or pharmacist) know that you are taking these two medications together. Your doctor may want to do tests to be sure your liver is working normally.Do not drink alcoholic beverages while you are taking these medicines.Contact your doctor if you experience persistent nausea, unusual fatigue, yellowing of the skin or eyes, or dark urine or pale stools.Your healthcare professionals (e.g. doctor or pharmacist) may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
- 1.Venho VM, Koskinen R. The effect of pyrazinamide, rifampicin and cycloserine on the blood levels and urinary excretion of isoniazid. Ann Clin Res 1971 Oct;3(5):277-80.
- 2.Llorens J, Serrano RJ, Sanchez R. Pharmacodynamic interference between rifampicin and isoniazid. Chemotherapy 1978;24(2):97-103.
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CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.