Medication Search: Rifater

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Common Name:

rifampin - isoniazid - pyrazinamide


How does this medication work? What will it do for me?

This combination product contains three medications: rifampin, isoniazid, and pyrazinamide. All three of these medications belong to the group of medications called antibiotics. This fixed combination of medications specifically belongs to the class of medications called antituberculous antibiotics. This medication is used to treat tuberculosis infections of the lung. Rifampin, isoniazid, and pyrazinamide all work to kill the bacteria that cause tuberculosis.

Other antituberculosis medications may also be used during the treatment of tuberculosis infection. This combination medication is used in the initial treatment (approximately first 2 months) of tuberculosis infection. Treatment must be continued after the first 2 months with rifampin and isoniazid for at least 4 more months.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

Rifampin – isoniazid – pyrazinamide is no longer being manufactured for sale in Canada and is no longer available under any brand names. This article is being kept available for reference purposes only. If you are using this medication, speak with your doctor or pharmacist for information about your treatment options.

How should I use this medication?

The recommended adult dose depends on body weight and will be determined by your doctor. The usual daily dose ranges from 4 to 6 tablets taken once a day.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

In order to get the best effect from this medication, rifampin – isoniazid – pyrazinamide should be taken around the same time each day. This medication should be taken on an empty stomach (1 hour before or 2 hours after a meal) and with a full glass of water.

Finish all of this medication, even you start to feel better. This will reduce the chance of the infection returning and becoming more difficult to treat.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from moisture, and keep it out of the reach of children.

This medication is available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms listed here. The forms available for the specific brand you have searched are listed under "What form(s) does this medication come in?"

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Do not take this medication if you:

  • are allergic to rifampin, isoniazid, pyrazinamide, or any ingredients of the medication
  • are taking the medications saquinavir and ritonavir
  • have a gout flare-up
  • have had a severe reaction to isoniazid (e.g., fever caused by the medication, chills, and arthritis)
  • have severe liver damage or acute liver disease

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • abdominal pain
  • acne
  • blurred vision
  • dizziness
  • drowsiness
  • fatigue
  • flu-like symptoms (chills, body ache, fever)
  • headache
  • heartburn
  • gas
  • itchiness
  • increased blood sugar
  • loss of appetite
  • nausea
  • rash
  • red-coloured tears, sweat, saliva, or urine
  • stomach upset
  • tingling sensation in arms and legs
  • vomiting

Although most of the side effects listed below don’t happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • confusion
  • muscle weakness
  • pain in joints or muscles
  • signs of bleeding, e.g.:
    • bleeding gums
    • unexplained nosebleeds
    • unusual bleeding or bruising
  • signs of gout (e.g., joint pain, swelling and warmth of joints)
  • symptoms of liver damage, e.g.:
    • darkened urine
    • fever
    • light-coloured stools
    • loss of appetite
    • nausea
    • vomiting
    • yellowing of skin or eyes
  • symptoms of pancreatitis, e.g.:
    • abdominal pain on the upper left side
    • back pain
    • chills
    • fever
    • nausea
    • rapid heartbeat
    • swollen abdomen
  • vision changes

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • diarrhea (watery and severe; may also be bloody)
  • hallucinations (seeing or hearing things that are not there)
  • seizure
  • signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort
  • symptoms of a serious allergic reaction, e.g.:
    • hives
    • difficulty breathing or shortness of breath
    • swelling of face or throat
  • unconsciousness

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Alcohol: Do not consume alcohol while taking this medication. Alcohol can increase the risk of liver problems with this medication.

Antibiotic-associated colitis: This medication, like other antibiotics, may cause a potentially dangerous condition called antibiotic-associated, or pseudomembranous, colitis. Symptoms include severe, watery diarrhea that may be bloody. If you notice these symptoms, stop taking rifampin – isoniazid – pyrazinamide and contact your doctor as soon as possible.

Birth control: Rifampin can reduce the effectiveness of birth control pills. It is important to use a backup method to contraception (i.e., latex condom) until rifampin – isoniazid – pyrazinamide therapy is finished.

Diabetes: This medication may raise blood glucose levels. People with diabetes should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Discoloration of body fluids: Rifampin may cause discoloration of body fluids (e.g., tears, sweat, saliva, or urine) to an orange-to-red colour. This side effect is not harmful. It may also stain soft contact lenses. You may want to consider wearing eyeglasses while taking this medication to avoid staining your contact lenses.

Eye problems: This medication may cause eye and vision problems. Your doctor will recommend regular eye examinations while you are taking this medication. If you experience any changes to your vision while taking rifampin – isoniazid – pyrazinamide, contact your doctor as soon as possible.

Food restriction: Isoniazid can interact with several types of food, especially those with high amounts of tyramine (e.g., cheese, beer, red wine, rye bread) and histamine (e.g., tuna and other tropical fish). Side effects include headache, sweating, flushing, low blood pressure, and dizziness. While using rifampin – isoniazid – pyrazinamide, try to avoid foods high in tyramine and histamine.

Gout: Rifampin – isoniazid – pyrazinamide can increase the levels of uric acid in the blood, increasing the risk of developing gout. Your doctor will monitor your blood uric acid levels while you are taking this medication.

If you develop painful, warm and swollen joints or difficulty with urination, contact your doctor as soon as possible.

People with a history of gout or kidney stones should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Kidney function: People with decreased kidney function should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: This combination medication contains 3 ingredients that can all cause liver problems. The liver effects can be serious and fatal, and can occur many months after treatment. The risk for liver problems increases with age and with daily alcohol intake. Your doctor will perform tests regularly to monitor your liver function. If you experience any symptoms of liver damage (e.g., yellowing of skin or eyes, darkened urine, light-coloured stools, loss of appetite, nausea, vomiting, fever, or unusual tiredness), contact your doctor immediately.

People with severe liver damage or active liver disease should not take this medication.

Pregnancy: The effect of these medications on an unborn baby is unclear. This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: Rifampin, isoniazid, and pyrazinamide pass into breast milk. If you are a breast-feeding mother and are taking rifampin – isoniazid – pyrazinamide, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The combination of these medications in the strengths contained in this product is not appropriate for children. Higher doses (per kilogram of body weight) of some medications are needed, while lower doses of other medications are needed. Although the individual medications are used to treat tuberculosis in children, this product is not considered appropriate.

What other drugs could interact with this medication?

There may be an interaction between rifampin – isoniazid – pyrazinamide and any of the following:

  • alcohol
  • alfuzosin
  • antacids
  • antiarrhythmics (e.g., mexiletine, quinidine, propafenone)
  • anticonvulsants (e.g., carbamazepine, phenytoin, valproic acid)
  • antidiabetes medications (e.g., glyburide, glimepiride)
  • antifungal medications (e.g., fluconazole, itraconazole, ketoconazole)
  • anti-HIV medications (e.g., indinavir, nelfinavir, zidovudine)
  • atovaquone
  • benzodiazepines (e.g., alprazolam, diazepam, triazolam)
  • beta-blockers (e.g., atenolol, metoprolol, propranolol)
  • birth control pills
  • buspirone
  • calcium channel blockers (e.g., diltiazem, nifedipine, nisoldipine verapamil)
  • chloramphenicol
  • colchicine
  • corticosteroids (e.g., dexamethasone, hydrocortisone, prednisone, prednisolone)
  • cyclosporine
  • dapsone
  • foods containing tyramine or histamine
  • gemfibrozil
  • haloperidol
  • halothane
  • imatinib
  • levodopa
  • levothyroxine
  • losartan
  • macrolide antibiotics (e.g., clarithromycin, erythromycin)
  • modafinil
  • mycophenolate
  • nefazodone
  • nilotinib
  • ondansetron
  • opioid pain relievers (e.g., alfentanil, fentanyl, codeine, hydrocodone, oxycodone)
  • praziquantel
  • protease inhibitors (e.g., atazanavir, darunavir, ritonavir, saquinavir)
  • quinine
  • quinolone antibiotics (e.g., ciprofloxacin, norfloxacin)
  • salmeterol
  • silodosin
  • sirolimus
  • sulfonylureas (e.g., sulfamethoxazole, sulfapyridine)
  • "statin" cholesterol-lowering medications (e.g., atorvastatin, lovastatin)
  • tacrolimus
  • tadalafil
  • tamoxifen
  • tamsulosin
  • temsiroliums
  • terfenadine
  • theophylline
  • thioridazine
  • thyroid medications (e.g., levothyroxine)
  • tricyclic antibiotics (e.g., amitriptyline, nortriptyline)
  • typhoid vaccine
  • warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

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Last Updated: 17/06/2024