Mycobutin (Rifabutin) – Oral

What Is Mycobutin?

Mycobutin (rifabutin) is an oral prescription medication used for bacterial infections. It is also known as an antimycobacterial antibiotic.

It kills bacteria by blocking the necessary proteins used to grow and spread. It is commonly used to prevent Mycobacterium avium complex (MAC) disease in people with advanced stages of human immunodeficiency virus (HIV).

Mycobutin is available in capsule form to take by mouth.

Drug Facts

Generic Name: Rifabutin

Brand Name(s): Mycobutin

Drug Availability: Prescription

Administration Route: Oral

Therapeutic Classification: Antimycobacterial

Available Generically: Yes 

Controlled Substance: N/A

Active Ingredient: Rifabutin 

Dosage Form(s): Capsule

What Is Mycobutin Used For?

The Food and Drug Administration (FDA) approved Mycobutin to prevent Mycobacterium avium complex (MAC) disease in people with advanced HIV infection.

HIV destroys CD4 cells, which are a type of white blood cell within the body that is important for fighting off infections by the immune system. When the CD4 count drops too far below normal, there is an increased risk of opportunistic infections such as MAC disease. MAC can easily spread throughout the body and become life-threatening without proper treatment. Rifabutin is one of the medications that can prevent this from occurring.

How to Use Mycobutin

As with all medications, rifabutin must be taken as instructed by your healthcare provider. It is a capsule taken by mouth daily at a dose of 300 milligrams (mg).

Mycobutin can be taken with or without food. If you experience nausea, vomiting, or stomach upset, it may help to take 150 milligrams twice per day with food.

Storage

Store your Mycobutin capsules at room temperature (between 68 and 77 degrees F) in a dry place. Do not store it in the bathroom or kitchen, where moisture occurs. Be sure to keep your medication out of the reach of children and pets to prevent accidental consumption.

Off-Label Uses

There are instances in which rifabutin may be prescribed for conditions outside of what has been approved. This is known as off-label use.

Off-label uses of rifabutin include:

How Long Does Mycobutin Take to Work?

There is limited information on how long it takes for rifabutin to work. However, just as with any antibiotic, it is important to take the full course as recommended by your healthcare provider to get its full benefits.

What Are the Side Effects of Mycobutin?

This is not a complete list of side effects, and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the FDA at www.fda.gov/medwatch or 800-FDA-1088.

Common Side Effects

The most common side effects of rifabutin include:

  • Diarrhea 
  • Upset stomach 
  • Color change in urine, saliva, stool, sweat, and skin to brown-orange 
  • Low blood cell counts

Other side effects that are not mentioned above may occur. Contact your healthcare provider for any further advice or concerns about side effects.

Severe Side Effects

Life-threatening side effects from rifabutin are rare. However, some symptoms are severe and should not be taken lightly. Seek medical help right away if you experience:

  • Signs of severe hypersensitivity (Stevens-Johnson Syndrome), characterized by rash, swelling, and shedding of the skin 
  • Signs of Clostridioides difficile (C. diff)–associated diarrhea (CDAD), characterized by loose, watery stools and stomach pain/cramping 
  • Shortness of breath 
  • An upset stomach that does not go away 
  • Chest pain or pressure 

Although these symptoms are rare, call your healthcare provider immediately if you experience any of these serious side effects. Call 911 if your symptoms feel life-threatening or if you think you are having a medical emergency.

Long-Term Side Effects

It is important to complete the full course of rifabutin and take it until your healthcare provider tells you to stop. You may or may not experience side effects with long-term use; however, there is the potential for these effects.

Uveitis is one potential side effect of long-term use with rifabutin. Uveitis is a rare, dose-related effect characterized by inflammation of the center eye.

Report Side Effects

Mycobutin may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your healthcare provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much Mycobutin Should I Take?

Drug Content Provided and Reviewed by IBM Micromedex®

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (capsules):
    • For the prevention of Mycobacterium avium complex (MAC):
      • Adults—300 milligrams (mg) once a day, or 150 mg two times a day with food.
      • Children—Use and dose must be determined by your doctor.

Modifications

Due to the possible effects of this medication, there may be changes to how it is taken, such as the following: 

  • Children (6 years and older): Dosing for children may be based on weight, at 5 milligrams/kilogram/dose. 
  • Advanced age: As you age, how your body reacts to medications may change. Your healthcare provider may recommend a lower dose of this medication to ensure safe treatment. 
  • Kidney issues: Rifabutin is mostly flushed from the body by the kidneys. If you have severe kidney issues, smaller doses of this medication may be recommended by your healthcare provider.

Missed Dose

For effective treatment, take this medication as directed by your healthcare provider. If you miss a dose of Mycobutin, take it as soon as you think about it.

If it is almost time for your next dose, skip the missed dose and continue your recommended schedule. Do not take extra doses or multiple doses at the same time. 

Overdose: What Happens If I Take Too Much Mycobutin?

There is limited information on a rifabutin overdose. If you take too much, the side effects mentioned above would likely be increased. To prevent an overdose, it is extremely important to take this medication as prescribed.

What Happens If I Overdose on Mycobutin?

If you think you or someone else may have overdosed on Mycobutin, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking Mycobutin, call 911 immediately.

Precautions

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It is very important that your doctor check your progress at regular visits. Blood and urine tests may be needed to check for unwanted effects.

Do not take this medicine together with delavirdine (Rescriptor®) or voriconazole (Vfend®).

This medicine may cause serious allergic reactions, including anaphylaxis, angioedema, or certain skin conditions, which can be life-threatening and require immediate medical attention. Call your doctor right away if you have a rash, itching, fever or chills, diarrhea, fast heartbeat, joint or muscle pain, red, irritated eyes, sore throat, trouble breathing or swallowing, large, hive-like swelling of the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs, tightness in the chest, or unusual tiredness or weakness while you are using this medicine.

Rifabutin will cause your urine, stools, saliva, skin, sputum, sweat, and tears to turn reddish-orange to brown-orange. This is to be expected while you are taking this medicine. This effect may cause soft contact lenses to become permanently discolored. Standard cleaning solutions may not take out all the discoloration. It is best not to wear soft contact lenses while taking this medicine. Hard contact lenses are not discolored by rifabutin. If you have any questions about this, check with your doctor.

Check with your doctor immediately if blurred vision, difficulty in reading, or any other change in vision occurs during or after treatment. Your doctor may want you to have your eyes checked by an ophthalmologist (eye doctor).

This medicine may cause diarrhea, and in some cases it can be severe. It may occur 2 months or more after you stop using this medicine. Do not take any medicine to treat diarrhea without first checking with your doctor. If you have any questions or if mild diarrhea continues or gets worse, check with your doctor.

Check with your doctor right away if you have black, tarry stools, blistering, peeling, loosening of the skin, chest pain, chills, cough, diarrhea, itching, joint or muscle pain, painful or difficult urination, red irritated eyes, red skin lesions, often with a purple center, sore throat, sores, ulcers, or white spots in the mouth or on the lips, swollen glands, unusual bleeding or bruising, or unusual tiredness or weakness. These may be symptoms of serious skin reactions (eg, Stevens-Johnson syndrome, toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms (DRESS)).

Rifabutin can lower the number of white blood cells in your blood temporarily, increasing the chance of getting infection. It can also lower the number of platelets, which are necessary for proper blood clotting. These problems may result in a greater chance of getting certain infections, slow healing, and bleeding of the gums. Be careful when using a regular toothbrush, dental floss, or toothpick. Dental work should be delayed until your blood counts have returned to normal. Check with your medical doctor or dentist if you have any questions about proper oral hygiene (mouth care) during treatment.

Birth control pills may not work properly if you take them while you are taking rifabutin. Unplanned pregnancies may occur. Use a different means of birth control while you are taking rifabutin. If you have any questions about this, check with your doctor.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

What Are Reasons I Shouldn’t Use Mycobutin?

Mycobutin may not be the right medication for you if you have hypersensitivity to its ingredients (allergic reaction). Signs of an allergic reaction include hives, fever, and swelling.

What Other Medications Interact With Mycobutin?

It is possible that taking certain medications with Mycobutin can negatively affect its ability to work correctly. Rifabutin has many drug interactions. Tell your provider about any other medicines you take or plan to take, including over-the-counter (OTC) nonprescription products, vitamins, herbs, supplements, and plant-based medicines

Medications that may interact with Mycobutin include: 

  • Mepron (atovaquone): Combined use of atovaquone with rifabutin may decrease the effectiveness of both drugs This combination should be avoided.
  • Prezista (darunavir): The use of these medications together may increase their concentrations in the body, increasing the risk of side effects. It is recommended to decrease the dose of both medications.
  • Hormonal contraceptives: Rifabutin may decrease the concentration of oral contraceptives within the body. It is recommended to use backup methods of pregnancy prevention while taking this medication.
  • Itraconazole/voriconazole: The use of these medications together may increase their concentrations and side effects. This combination should be avoided. 
  • Latuda (lurasidone): Rifabutin may decrease the concentration and effectiveness of lurasidone.

Please be aware that this does not list all interactions with rifabutin. Always let your healthcare provider or pharmacist know what medications you are currently taking so that they can ensure your treatment regimen is appropriate.

What Medications Are Similar?

Rifabutin is within an antibacterial class known as rifamycins. The other medications within this class include:

Rifabutin is also commonly used with other medications for MAC and tuberculosis. Other medications that are used along with rifabutin are:

Frequently Asked Questions

  • How long should I take Mycobutin?

    The amount of time to take this medication will be determined by your healthcare provider. Do not take more or less of what you were prescribed. Typically, this medication will be taken until there is no longer a risk of infection.

  • Why is my urine a different color after taking Mycobutin? Should I be concerned?

    Rifabutin is a red-colored medication that can make your bodily fluids change to a bright red-orange. This is completely normal and is not harmful.

  • Can I open the capsule before taking it?

    Yes, if you are unable to swallow the capsule you can open it and mix its contents with applesauce. Be sure to eat the applesauce immediately and not store it for future consumption.

  • Can I wear contacts while taking Mycobutin?

    Rifabutin can change the color of your body fluids to a bright red-orange. This can include your urine as well as your sweat and tears. Although harmless, it can cause permanent discoloration to your contacts.

How Can I Stay Healthy While Taking Mycobutin?

MAC disease is a common complication of advanced HIV disease. Therefore, staying adherent to your treatment regimen is important to staying healthy.

The best method for preventing MAC, and other opportunistic infections related to HIV/AIDS, is to take your HIV treatment and other prescribed medications as directed. In addition, you also should take care of your general health, which may involve eating a healthy diet, exercising, and getting recommended vaccinations. This can help keep your immune system strong and lower the risk of getting sick.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended to replace medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

The author would like to recognize and thank Faith Awoniyi for contributing to this article.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  5. Frank MO. Rifabutin and uveitis. N Engl J Med. 1994;330(12):868. doi:10.1056/NEJM199403243301218.