Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
Rifampin and pyrazinamide are used with two other medicines to treat tuberculosis (TB). They are also used together without other agents to prevent TB. When they are used together to prevent TB, they can damage your liver. Your risk of having liver damage from using these medicines together may be greater if you already have some liver problems, if you are taking other medicines that can damage your liver, if you developed liver damage while taking isoniazid (another medicine for TB), or if you are an alcoholic.
What might happen:
Your liver could be damaged. Severe liver damage could result in death.
What you should do about this interaction:
Let your healthcare professionals (e.g. doctor or pharmacist) know if you have any liver problems, all the medicines that you are taking (including over-the-counter medicines), if you had problems with your liver after taking isoniazid, or if you are an alcoholic.If your doctor determines that taking rifampin and pyrazinamide together is the best way to prevent you from developing TB, you will be monitored closely by your healthcare professionals. Your pharmacist may only give you a two-week supply of your medicines. Your doctor may check your blood every two weeks to see if the medicines have affected your liver before approving another two week supply of your medicines.Take your medicines exactly as prescribed. Keep all appointments with your doctor and for lab tests. If you have any abdominal pain, vomiting, or if notice that your skin or eyes are turning yellow, stop taking your rifampin and pyrazinamide and contact your doctor right away.Your healthcare professionals 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.Anonymous. Update: Fatal and severe liver injuries associated with rifampin and pyrazinamide for latent tuberculosis infection, and revisions in American Thoracic Society/CDC recommendations--United States, 2001. MMWR Morb Mortal Wkly Rep 2001 Aug 31;50(34):733-5.
2.Anonymous. Update: adverse event data and revised American Thoracic Society/CDC recommendations against the use of rifampin and pyrazinamide for treatment of latent tuberculosis infection--United States, 2003. MMWR Morb Mortal Wkly Rep 2003 Aug 8;52(31):735-9.