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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.

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.

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

Rifater 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.

Many drugs can interact and cause dangerous effects. Some drugs should not be used together with Rifater. 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.

In animal studies, isoniazid and rifampin have caused miscarriage or birth defects. It is not known whether these effects would occur in a human pregnancy. However, taking rifampin during the last few weeks of pregnancy may cause bleeding in the mother or the newborn baby. Tell your doctor if you are pregnant.

If you take Rifater during pregnancy, be sure to tell the doctor who delivers your baby. Both you and the baby may need to receive medications to prevent excessive bleeding in the baby just after birth.

Rifater 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 Rifater.

How should I take this medicine?

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 Rifater.

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 Rifater.

Rifater is usually given for at least 4 months, or after lab tests show that your tuberculosis has cleared. Use this medicine for the full prescribed length of time, even if your symptoms quickly improve.

Try not to miss any doses. Skipping doses can increase your risk of infection that is resistant to medication. Rifater will not treat a viral infection such as the flu or a common cold.

Store at room temperature away from moisture and heat.

Your doctor may have you take extra vitamin B6 while you are taking Rifater. Take only the amount of vitamin B6 that your doctor has prescribed.

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 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?

Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, call your doctor before using anti-diarrhea medicine.

Avoid drinking alcohol. It may increase your risk of liver damage.

Avoid taking an antacid within 1 hour after you take Rifater. 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).

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.

Rifater 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:

  • numbness or tingling;
  • 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.

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.

Rifater 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.

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.

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