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Isoniazid, pyrazinamide, and rifampin

Generic Name: isoniazid, pyrazinamide, and rifampin (EYE soe NYE a zid, PIR a ZIN a mide, and rif AM pin)
Brand Name: Rifater

Medically reviewed by Drugs.com on Oct 7, 2019 – Written by Cerner Multum

What is isoniazid, pyrazinamide, and rifampin?

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

Isoniazid, pyrazinamide, and rifampin is a combination medicine used to treat tuberculosis (TB) in adults and children at least 15 years old.

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

Important Information

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.

Isoniazid, pyrazinamide, and rifampin 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, loss of appetite, or yellowing of your skin or eyes.

Tell your doctor about all your current medicines and any you start or stop using. Many drugs can interact, and some drugs should not be used together.

Avoid drinking alcohol.

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.

Many drugs can interact and cause dangerous effects. Some drugs should not be used together with isoniazid, pyrazinamide, and rifampin. Your doctor may change your treatment plan if you also use: atazanavir, darunavir, fosamprenavir, praziquantel, 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.

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, cervical cap, or contraceptive sponge) to prevent pregnancy.

You should not breastfeed while using this medicine.

How should I take isoniazid, pyrazinamide, and rifampin?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

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.

Rifampin 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 this medicine.

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).

This medicine may affect a drug-screening urine test and you may have false results. Tell the laboratory staff that you use isoniazid, pyrazinamide, and rifampin.

Use this medicine for the full prescribed length of time, even if your symptoms quickly improve. Skipping doses can increase your risk of infection that is resistant to medication. 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 medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of isoniazid, pyrazinamide, and rifampin 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 drinking alcohol. It may increase your risk of liver damage.

Avoid taking an antacid within 1 hour 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.

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

isoniazid, pyrazinamide, and rifampin side effects

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).

Seek medical treatment if you have a serious drug reaction that can affect many parts of your body. Symptoms may include: skin rash, fever, swollen glands, muscle aches, severe weakness, unusual bruising, and joint pain or stiffness.

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, loss of appetite, or yellowing of your skin or eyes.

Also call your doctor right away if you have:

  • numbness, tingling, or burning pain in your hands or feet;

  • vision problems, pain behind your eyes;

  • wheezing, trouble breathing; or

  • severe stomach pain, diarrhea that is watery or bloody.

Common side effects may include:

  • red discoloration of your teeth, sweat, urine, saliva, and tears;

  • 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.

Isoniazid, pyrazinamide, and rifampin dosing information

Usual Adult Dose for Tuberculosis -- Active:

Up to 44 kg: Isoniazid 200 mg-pyrazinamide 1200 mg-rifampin 480 mg orally once a day
Between 45 and 54 kg: Isoniazid 250 mg-pyrazinamide 1500 mg-rifampin 600 mg orally once a day
55 kg and greater: Isoniazid 300 mg-pyrazinamide 1800 mg-rifampin 720 mg orally once a day
Duration of therapy: 2 months

Comments:
-The dose should be taken with a full glass of water 1 hour before or 2 hours after a meal.
-After 2 months this this drug combination, treatment should be continued with rifampin and isoniazid for at least 4 months.

Use: Initial phase of the short-course treatment of susceptible pulmonary tuberculosis

Usual Pediatric Dose for Tuberculosis -- Active:

15 Years and Older:
Up to 44 kg: Isoniazid 200 mg-pyrazinamide 1200 mg-rifampin 480 mg orally once a day
Between 45 and 54 kg: Isoniazid 250 mg-pyrazinamide 1500 mg-rifampin 600 mg orally once a day
55 kg and greater: Isoniazid 300 mg-pyrazinamide 1800 mg-rifampin 720 mg orally once a day
Duration of therapy: 2 months

Comments:
-The dose should be taken with a full glass of water 1 hour before or 2 hours after a meal.
-After 2 months this this drug combination, treatment should be continued with rifampin and isoniazid for at least 4 months.

Use: Initial phase of the short-course treatment of susceptible pulmonary tuberculosis

What other drugs will affect isoniazid, pyrazinamide, and rifampin?

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.

Isoniazid, pyrazinamide, and rifampin can harm your liver, especially if you also use certain medicines for infections, tuberculosis, depression, birth control, hormone replacement, high cholesterol, heart problems, high blood pressure, seizures, pain, or arthritis (including Tylenol, Advil, Motrin, or Aleve).

Many drugs can affect isoniazid, pyrazinamide, and rifampin, and some drugs should not be used at the same time. Tell your doctor about all your current medicines and any medicine you start or stop using. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.

Further information

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.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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