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Generic Name: isoniazid/rifampin (EYE-soe-NYE-a-zid/rif-AM-pin)
Brand Name: Examples include Rifamate and Isonarif

Isonarif may cause severe and sometimes fatal liver problems (eg, hepatitis). The risk of liver problems is greater in patients over 35 years old. It may also be increased by daily use of alcohol, long-term liver problems, or unsanitary injectable drug use. Women, especially those who are black, are Hispanic, or have just had a baby, may also be at increased risk. Hepatitis can develop at any time during treatment, but usually occurs during the first 3 months. Your doctor will monitor your liver function and discuss your progress every month.

Contact your doctor right away if you develop unusual fatigue, weakness or fever that lasts longer than 3 days, general feeling of discomfort, loss of appetite, nausea, vomiting, numbness or tingling of the hands or feet, dark urine, yellowing of the skin or eyes, or stomach pain or tenderness.

Patients with active liver problems should not use Isonarif.

Isonarif is used for:

Treating tuberculosis (TB) of the lungs.

Isonarif is a combination of 2 antibacterial agents. It works by killing TB bacteria.

Do NOT use Isonarif if:

  • you are allergic to any ingredient in Isonarif or to any rifamycin (eg, rifabutin)
  • you have had severe side effects from isoniazid, such as drug fever, chills, or arthritis
  • you have severe liver damage, active liver disease, or liver damage from previous use of Isonarif
  • you have a history of hepatitis caused by any medicine
  • you are taking atazanavir, cabazitaxel, darunavir, delavirdine, dronedarone, etravirine, fosamprenavir, lurasidone, nifedipine praziquantel, ranolazine, saquinavir, tipranavir, a tyrosine kinase receptor inhibitor (eg, lapatinib), or voriconazole

Contact your doctor or health care provider right away if any of these apply to you.

Before using Isonarif:

Some medical conditions may interact with Isonarif. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

  • if you are pregnant, planning to become pregnant, or are breast-feeding
  • if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
  • if you have allergies to medicines, foods, or other substances
  • if you have diabetes, the blood disease porphyria, kidney problems, nerve problems (eg, neuropathy) or risk of nerve problems, HIV, severe diarrhea due to antibiotic use (pseudomembranous colitis), or a history of liver problems or gout
  • if you have a history of alcohol or other substance abuse, have unsanitary injectable drug habits, or drink alcohol daily
  • if you are over 35 years old, you have recently given birth, or you have previously taken Isonarif
  • if you wear contact lenses

Some MEDICINES MAY INTERACT with Isonarif. Tell your health care provider if you are taking any other medicines, especially any of the following:

  • Atazanavir, cabazitaxel, darunavir, delavirdine, dronedarone, etravirine, fosamprenavir, lurasidone, nifedipine, praziquantel, ranolazine, saquinavir, tipranavir, tyrosine kinase receptor inhibitors (eg, lapatinib), or voriconazole because their effectiveness may be decreased by Isonarif
  • Many prescription and nonprescription medicines (eg, used for alcoholism, asthma, cancer, infections, inflammation, aches and pains, heart problems, high blood pressure, high blood iron levels, high cholesterol, blood thinning, birth control, diabetes, HIV, hormone replacement, immune system suppression, irregular heartbeat, low sodium levels, low vitamin D levels, mental or mood problems, nausea and vomiting, Parkinson disease, seizures, sleep, thyroid) may interact with Isonarif, increasing the risk of side effects or decreasing effectiveness.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Isonarif may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Isonarif:

Use Isonarif as directed by your doctor. Check the label on the medicine for exact dosing instructions.

  • Take Isonarif by mouth on an empty stomach at least 1 hour before or 2 hours after eating.
  • If you also take an antacid, take Isonarif at least 1 hour before you take the antacid.
  • If you also take aminosalicylic acid granules, do not take it within 8 to 12 hours of Isonarif. Check with your doctor if you have questions.
  • Continue to take Isonarif even if you feel well. Do not miss any doses.
  • Do not stop taking Isonarif without checking with your doctor. Rarely, kidney problems have occurred when patients started taking Isonarif again after therapy was interrupted.
  • If you miss a dose of Isonarif, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Isonarif.

Important safety information:

  • Isonarif may cause drowsiness or dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Isonarif with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
  • Check with your doctor before drinking alcohol while taking Isonarif. Alcohol may increase the risk of liver problems. If you have a history of alcohol abuse, you may also be at increased risk of developing nerve problems from Isonarif. Notify your doctor if you notice any unusual tingling in your hands or feet.
  • If you have a history of diabetes, alcohol abuse, or poor nutrition, your doctor may recommend that you also take vitamin B6 while you are taking Isonarif. This may help to decrease your risk of nerve problems. Discuss any questions with your doctor.
  • Isonarif may cause a reddish orange color of urine, stools, saliva, tears, sweat, sputum, and skin. This is normal and not a cause for concern.
  • Isonarif may cause a permanent reddish orange color of soft contact lenses.
  • Eating foods high in tyramine (eg, aged cheeses, red wines, beer, certain meats and sausages, liver, sour cream, soy sauce, raisins, bananas, avocados) while you use Isonarif may cause severe high blood pressure. Do not eat foods high in tyramine while you take Isonarif. Seek medical attention at once if symptoms of severe high blood pressure occur. These may include severe headache, fast or irregular heartbeat, sore or stiff neck, nausea, vomiting, sweating, enlarged pupils, or sensitivity to light.
  • Do not eat foods high in histamine while you take Isonarif. Eating foods high in histamine (eg, skipjack, tuna, tropical fish) while you use Isonarif may cause low blood pressure, irregular heartbeat, headache, sweating, or flushing. Contact your doctor at once if any of these symptoms occur.
  • Ask your health care provider for a complete list of foods you should avoid while you are taking Isonarif.
  • Hormonal birth control (eg, birth control pills, implants, patches) may not work as well while you are using Isonarif. To prevent pregnancy, use an extra form of birth control (eg, condoms).
  • Isonarif only works against TB bacteria; it does not treat viral infections (eg, the common cold).
  • Be sure to take Isonarif for the full course of treatment. If you do not, the medicine may not clear up your infection completely. The bacteria could also become less sensitive to this or other medicines. This could make the infection harder to treat in the future.
  • Mild diarrhea is common with antibiotic use. However, a more serious form of diarrhea (pseudomembranous colitis) may rarely occur. This may develop while you take the antibiotic or within several months after you stop taking it. Contact your doctor right away if stomach pain or cramps, severe diarrhea, or bloody stools occurs. Do not treat diarrhea without first checking with your doctor.
  • Tell your doctor or dentist that you take Isonarif before you receive any medical or dental care, emergency care, or surgery.
  • Diabetes patients - Isonarif may affect your blood sugar. Check blood sugar levels closely. Ask your doctor before you change the dose of your diabetes medicine. You may also be at increased risk of developing nerve problems from Isonarif. Contact your doctor if you notice any unusual tingling in your hands or feet.
  • Isonarif may interfere with certain lab tests. Be sure your doctor and lab personnel know you are taking Isonarif.
  • Lab tests, including complete blood cell counts, platelet counts, uric acid levels, kidney and liver function, and eye exams, may be performed while you take Isonarif. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
  • Use Isonarif with caution in BLACK and HISPANIC WOMEN; they may have a greater risk of severe liver problems from Isonarif.
  • Use Isonarif with caution in patients over 35 years old; they may have a greater risk of severe liver problems from Isonarif.
  • Isonarif should be used with extreme caution in CHILDREN; safety and effectiveness in children have not been confirmed.
  • PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of taking Isonarif while you are pregnant. Isonarif is found in breast milk. If you are or will be breast-feeding while you take Isonarif, check with your doctor. Discuss any possible risks to your baby.

Possible side effects of Isonarif:

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Diarrhea; dizziness; drowsiness; gas; headache; heartburn; mild stomach upset or cramps; nausea; trouble sleeping.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); bloody or dark urine; change in the amount of urine produced; changes in vision; dark, tarry, or bloody stools; fever, chills, or sore throat; general feeling of discomfort; increased thirst or urination; joint pain or swelling; loss of appetite; memory problems; menstrual changes; mental or mood changes; muscle pain or weakness; seizures; severe diarrhea, nausea, or stomach cramps; shortness of breath; stomach pain or tenderness; swelling of the hands or legs; symptoms of low vitamin B6 levels (eg, confusion, cracks in the corners of the mouth, irritability, mouth redness or soreness, scaly rash); tingling or numbness in the hands or feet; unusual bruising or bleeding; unusual tiredness or weakness; vomiting; yellowing of the skin or eyes.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately. Symptoms may include blurred vision; hallucinations; loss of consciousness; seizures; severe dizziness or nausea; sluggishness; slurred speech; stomach pain or tenderness; symptoms of high blood sugar (eg, confusion, increased thirst or urination, rapid breathing, unusual drowsiness); very slow breathing; vomiting; yellowing of the skin or eyes.

Proper storage of Isonarif:

Store Isonarif between 68 and 77 degrees F (20 and 25 degrees C). Store away from heat, moisture, and light. Do not store in the bathroom. Keep Isonarif out of the reach of children and away from pets.

General information:

  • If you have any questions about Isonarif, please talk with your doctor, pharmacist, or other health care provider.
  • Isonarif is to be used only by the patient for whom it is prescribed. Do not share it with other people.
  • If your symptoms do not improve or if they become worse, check with your doctor.
  • Check with your pharmacist about how to dispose of unused medicine.

This information should not be used to decide whether or not to take Isonarif or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about Isonarif. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to Isonarif. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using Isonarif.

Issue Date: June 3, 2015