Rifabutin

Generic name: rifabutin
Brand name: Mycobutin
Dosage form: oral capsule (150 mg)
Drug class: Rifamycin derivatives

Medically reviewed by A Ras MD.

What is rifabutin used for?

Rifabutin is a prescription medicine that is used to prevent an infection in people with HIV. Rifabutin may be given to you for other reasons.

Description

Rifabutin capsules for oral administration contain 150 mg of the rifamycin antimycobacterial agent rifabutin, USP, per capsule, along with the inactive ingredients, microcrystalline cellulose, magnesium stearate, red iron oxide, silica gel, sodium lauryl sulfate, titanium dioxide, and edible white ink.

The chemical name for rifabutin is 1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxorifamycin XIV (Chemical Abstracts Service, 9th Collective Index) or (9S,12E,14S,15R,16S,17R,18R,19R,20S,21S,22E,24Z)-6,16,18,20-tetrahydroxy-1′-isobutyl-14-methoxy-7,9,15,17,19,21,25-heptamethyl-spiro [9,4-(epoxypentadeca[1,11,13]trienimino)-2H-furo[2′,3′:7,8]naphth[1,2-d] imidazole-2,4′-piperidine]-5,10,26-(3H,9H)-trione-16-acetate. Rifabutin has a molecular formula of C46H62N4O11, a molecular weight of 847.02 and the following structure:

Rifabutin is a red-violet powder soluble in chloroform and methanol, sparingly soluble in ethanol, and very slightly soluble in water (0.19 mg/mL). Its log P value (the base 10 logarithm of the partition coefficient between n-octanol and water) is 3.2 (n-octanol/water).

Before taking rifabutin, tell your doctor:

If you are allergic to rifabutin; any part of this medicine; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
If you have active TB (tuberculosis).
If you are taking any of these drugs: Delavirdine or voriconazole.
If you are breast-feeding or plan to breast-feed.

This is not a list of all drugs or health problems that interact with rifabutin.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take rifabutin with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take rifabutin?

Tell all of your health care providers that you take rifabutin. This includes your doctors, nurses, pharmacists, and dentists.
Have blood work checked as you have been told by the doctor. Talk with the doctor.
Allergic side effects may rarely happen.
This medicine may stain contact lenses.
This medicine may change the color of urine, stools, saliva, sweat, tears, and skin to a brown-orange color. This is normal and not harmful.
Birth control pills and other hormone-based birth control may not work as well to prevent pregnancy. Use some other kind of birth control also like a condom when taking rifabutin.
Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using rifabutin while you are pregnant.

How is rifabutin best taken?

Use rifabutin as ordered by your doctor. Read all information given to you. Follow all instructions closely.

Take with or without food. Take with food if it causes an upset stomach.
You may swallow whole or mix the contents of the capsule with certain foods like applesauce. Take the mixture right away. Do not store for later use.
Keep taking rifabutin as you have been told by your doctor or other health care provider, even if you feel well.

What do I do if I miss a dose?

Take a missed dose as soon as you think about it.
If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
Do not take 2 doses at the same time or extra doses.

What are the side effects of rifabutin that I need to call my doctor about immediately?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
Chest pain or pressure.
Flu-like signs. These include headache, weakness, fever, shakes, aches, pains, and sweating.
Feeling very tired or weak.
Shortness of breath.
Change in eyesight, eye pain, or very bad eye irritation.
Dizziness or passing out.
Very upset stomach or throwing up.
Coughing.
A heartbeat that does not feel normal.
Diarrhea is common with antibiotics. Rarely, a severe form called C diff–associated diarrhea (CDAD) may happen. Sometimes, this has led to a deadly bowel problem (colitis). CDAD may happen during or a few months after taking antibiotics. Call your doctor right away if you have stomach pain, cramps, or very loose, watery, or bloody stools. Check with your doctor before treating diarrhea.
Low white blood cell counts have happened with rifabutin. This may lead to a higher chance of getting an infection. Call your doctor right away if you have signs of infection like fever, chills, or sore throat.
Low platelet counts have rarely happened with rifabutin. This may lead to a higher chance of bleeding. Call your doctor right away if you have any unexplained bruising or bleeding.

What are some other side effects of rifabutin?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

Diarrhea.
Upset stomach.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

If overdose is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out rifabutin?

Store at room temperature.
Store in a dry place. Do not store in a bathroom.
Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.