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isoniazid, pyrazinamide, and rifampin

Pronunciation: EYE soe NYE a zid, PIR a ZIN a mide, and rif AM pin

Brand: Rifater

What is the most important information I should know about this medicine?

You should not use this medicine if you have severe liver disease, an attack of gout, if you take certain antiviral medicines, or if you have a history of fever, chills, and joint pain or stiffness caused by isoniazid.

This medicine can cause severe liver symptoms, especially in people who are 35 and older. Your liver function will need to be checked often.

Call your doctor at once if you have: nausea, vomiting, upper stomach pain, weakness, tiredness, or loss of appetite.

Avoid drinking alcohol.

What is isoniazid, pyrazinamide, and rifampin?

Isoniazid, pyrazinamide, and rifampin are antibiotics. They prevent tuberculous bacteria from multiplying in your body.

Isoniazid, pyrazinamide, and rifampin is a combination medicine used to treat tuberculosis (TB).

Isoniazid, pyrazinamide, and rifampin may also be used for purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking this medicine?

You should not use this medicine if you are allergic to isoniazid, pyrazinamide, or rifampin, or if you have:

  • severe liver disease;
  • an attack of gout; or
  • a history of fever, chills, and joint pain or stiffness caused by isoniazid.

Some medicines can cause unwanted or dangerous effects when used with rifampin. Your doctor may need to change your treatment plan if you use any of the following antiviral medicines--atazanavir, darunavir, fosamprenavir, ritonavir, saquinavir, or tipranavir.

Serious and sometimes fatal liver problems may occur during treatment with this medicine or even months after you stop taking it. The risk of liver problems is highest in adults between the ages of 35 and 65.

To make sure isoniazid, pyrazinamide, and rifampin is safe for you, tell your doctor if you have ever had:

  • liver disease;
  • alcoholism (or if you drink alcoholic beverages every day);
  • gout;
  • diabetes; or
  • kidney disease.

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Rifampin can make birth control pills less effective. Ask your doctor about using a non-hormonal birth control (condom, diaphragm with spermicide) to prevent pregnancy.

Isoniazid, pyrazinamide, and rifampin can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.

How should I take this medicine?

Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Take this medicine on an empty stomach, at least 1 hour before or 2 hours after a meal. Take each dose with a full glass of water.

Your doctor may perform tests to make sure your tuberculosis is not resistant to this medicine. You may also need frequent eye examinations to check your vision.

Your liver function may need to be checked every month while you are taking this medicine, and for a short time after your last dose.

This medicine may cause temporary discoloration of your teeth, sweat, urine, saliva, and tears (a yellow, orange, red, or brown color). This side effect is usually not harmful. However, soft contact lenses may be permanently stained if you wear them while taking isoniazid, pyrazinamide, and rifampin.

Dark colored urine can be a sign of liver problems. Call your doctor if you have reddish-brown urine together with upper stomach pain, loss of appetite, and jaundice (yellowing of your skin or eyes).

Rifampin and pyrazinamide can cause unusual results with certain medical tests, including a false positive drug screening test. Tell any laboratory staff or doctor or who treats you that you are using isoniazid, pyrazinamide, and rifampin.

Use this medicine for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared. Skipping doses may also increase your risk of further infection that is resistant to antibiotics. Isoniazid, pyrazinamide, and rifampin will not treat a viral infection such as the flu or a common cold.

Your doctor may have you take extra vitamin B6 while you are taking isoniazid, pyrazinamide, and rifampin. Take only the amount of vitamin B6 that your doctor has prescribed.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of this medicine can be fatal, especially when combined with alcohol.

Early symptoms of an overdose may include nausea, vomiting, stomach pain, lack of energy, headache, and itching. Later symptoms may include severe stomach pain, yellowing of your skin or eyes, body fluids that are dark brown or dark red-orange, swelling in your face, seizure, or loss of consciousness.

What should I avoid while taking this medicine?

Avoid wearing contact lenses. This medicine may discolor your tears, which could permanently stain soft contact lenses.

Avoid drinking alcohol. It may increase your risk of liver damage while you are taking this medicine.

Avoid taking an antacid within 1 hour before or after you take isoniazid, pyrazinamide, and rifampin. Some antacids can make it harder for your body to absorb this medicine.

Avoid foods that are high in tyramine or histamine, listed below. Tyramine or histamine can interact with this medication and cause unpleasant side effects. These foods include:

  • beer or wine (especially red wine);
  • cheese (especially aged or processed cheeses);
  • soy sauce, miso soup, fava beans; or
  • pickled or smoked fish, herring, tuna, skipjack, or other tropical fish.

What are the possible side effects of this medicine?

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning in your eyes, skin pain, red or purple skin rash that spreads and causes blistering and peeling).

Isoniazid, pyrazinamide, and rifampin can cause severe liver symptoms, especially in people who are 35 and older. Call your doctor at once if you have any of these early signs of liver damage: nausea, vomiting, upper stomach pain, weakness, tiredness, or loss of appetite.

Also tell your doctor right away if you have:

  • numbness, tingling, or burning pain in your hands or feet;
  • vision problems, pain behind your eyes;
  • fever, flu symptoms, swollen glands;
  • wheezing, trouble breathing; or
  • severe stomach pain, diarrhea that is watery or bloody.

Common side effects may include:

  • red discoloration of your tears, sweat, saliva, urine, or stools;
  • nausea, vomiting, stomach pain;
  • mild rash or itching; or
  • joint or muscle pain.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect this medicine?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Many drugs can interact with isoniazid, pyrazinamide, and rifampin. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any you start or stop using, especially:

  • vitamin D;
  • antibiotic, antifungal, or antiviral medicine;
  • birth control pills or hormone replacement therapy;
  • a blood thinner (warfarin, Coumadin, Jantoven); or
  • medicine to treat conditions such as diabetes, high blood pressure, heart problems, a thyroid disorder, or seizures.

This list is not complete and many other drugs can interact with isoniazid, pyrazinamide, and rifampin. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Give a list of all your medicines to any healthcare provider who treats you.

Where can I get more information?

Your pharmacist can provide more information about isoniazid, pyrazinamide, and rifampin.


Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

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