Mycobutin

(Rifabutin)

The active ingredient in Mycobutin is rifabutin. Rifabutin belongs to a group of antibiotics called rifamycins, and it targets the bacteria that cause MAC and some other mycobacterial infections. Interfering with key bacterial processes helps stop these bacteria from multiplying, so your immune system has a better chance of controlling or preventing infection.

Follow all directions given to you by your doctor and read all documents provided, including the full Prescribing Information, FDA-Approved Product Labeling, Instructions for Use, and Medication Guide before using Mycobutin. However, the following is a synopsis of the general guidelines for the use of Mycobutin:

• Take Mycobutin exactly as prescribed, usually once daily or in two divided doses. Do not change your dose or schedule without your healthcare provider’s advice.
• You may take the capsules with or without food. If they upset your stomach, taking them with food may help.
• Swallow the capsule whole. If you cannot swallow capsules, your doctor may allow you to open the capsule and mix the contents with a small amount of soft food like applesauce. Make sure you eat all of it to get the full dose.
• Take Mycobutin at the same time each day to keep a steady level in your body.
• If you miss a dose, take it as soon as you remember, unless it is almost time for your next dose. If it is near the time of the next dose, skip the missed dose and continue your regular schedule. Do not take two doses at once.

Some mild or common side effects of Mycobutin seen in clinical trials include:

• Discoloration of urine, stools, sweat, tears, saliva, or skin.
• Discoloration of dentures or contact lenses.
• Nausea, vomiting, or diarrhea.
• Gas, bloating, or an unpleasant taste in the mouth.
• Headache.
• Rash.

Some individuals may experience serious side effects while using Mycobutin. These side effects may require immediate medical attention. If you experience any of the following, contact your healthcare provider or seek emergency medical help:

• Signs of serious allergic reaction, such as difficulty breathing, chest tightness, swelling of the face, lips, tongue, or throat, hives, or severe skin rash.
• Severe skin reactions, such as widespread rash, blistering, peeling skin, or symptoms of conditions like Stevens-Johnson Syndrome (SJS), acute generalized exanthematous pustulosis (AGEP), and Toxic Epidermal Necrolysis (TEN), or drug reaction with eosinophilia and systemic symptoms (DRESS).
• Signs of infection from low white blood cell counts, such as fever, chills, sore throat, cough, mouth sores, or trouble breathing.
• Eye pain, redness, blurred vision, or other vision changes that could suggest uveitis.
• Chest pain, shortness of breath, or pressure in the chest.
• Yellowing of the skin and eyes, itchy skin, and dark urine (symptoms of jaundice).
• Severe or persistent diarrhea, especially if it is watery or bloody, could indicate a serious bowel infection such as C. difficile.

These are not all of the possible side effects of Mycobutin. You should always seek medical advice from your healthcare provider for any questions or concerns about your medical condition or treatment. Read all patient information, medication guides, or drug information sheets that come with this medication. You can also report adverse effects to the Food and Drug Administration at www.fda.gov/medwatch or 1-800-FDA-1088.

Before starting Mycobutin, it is crucial to discuss any existing health conditions with your healthcare provider. You should be sure that your healthcare provider is aware of all your medical conditions, including:

• A history of active or previous tuberculosis, or close contact with someone with tuberculosis.
• Liver disease or abnormal liver tests.
• Kidney disease, especially severe kidney problems.
• A history of uveitis (inflammation inside the eye) or other serious eye conditions.
• Muscle disorders such as myositis, or unexplained muscle pain or weakness.
• Low blood cell counts or previous problems with anemia, neutropenia, or low platelets.
• Other serious infections or a very weak immune system.

Mycobutin should not be used in the following situations:

• Known hypersensitivity or serious allergic reaction to rifabutin, any other rifamycin (such as rifampin or rifapentine), or any component of the capsule.
• Use for MAC prophylaxis in a patient with active tuberculosis that is not being treated with a full TB regimen.
• Use together with certain HIV medicines, including delavirdine, or with some long-acting cabotegravir/rilpivirine injection regimens, where co-administration is listed as contraindicated in product labeling.

Mycobutin starts acting against bacteria soon after you begin taking it, but its benefit in MAC is mainly preventive. For patients with advanced HIV infection, it is taken regularly over many months to reduce the chance of MAC spreading throughout the body.

When Mycobutin is taken with other prescription drugs, over-the-counter medications, vitamins, and supplements, it may change how they work or increase the frequency or severity of side effects. Make sure that you tell your healthcare professional about anything that you are taking to avoid any negative drug interactions, including:

• HIV protease inhibitors such as indinavir, ritonavir, lopinavir, saquinavir, fosamprenavir, atazanavir, or darunavir.
• Other HIV medicines, including some integrase inhibitors and non-nucleoside reverse transcriptase inhibitors (such as bictegravir, rilpivirine, elvitegravir/cobicistat, or doravirine).
• Certain antibiotics, such as clarithromycin or erythromycin.
• Antifungal medicines such as fluconazole, itraconazole, posaconazole, or voriconazole.
• Some hepatitis C medicines (such as boceprevir, simeprevir, or telaprevir).
• Hormonal birth control/contraceptives containing ethinyl estradiol or other estrogen/progestin combinations.
• Warfarin and similar blood thinners.
• Sofosbuvir.
• Zidovudine.
• Azithromycin.

Mycobutin is available as 150 mg oral capsules.

For adults, the usual dose for prevention of MAC in advanced HIV infection is 300 mg once daily, or 150 mg twice daily, as directed by your healthcare provider.

Dosing in children must be determined individually by a doctor, as safety and effectiveness data are more limited.

Store at room temperature and keep out of reach of children.

Mycobutin is marketed by Pharmacia & Upjohn (a division of Pfizer) in several regions, according to the official prescribing information and product references.

Yes. Rifabutin is the generic name for Mycobutin, and generic rifabutin 150 mg capsules are approved and available from multiple manufacturers.

Do not stop taking Mycobutin without talking to your healthcare provider. Stopping too early can increase your risk of developing MAC or other infections, especially if your immune system is very weak.

Talk to your doctor if you are already pregnant or if you have any plans to become pregnant. They will know or recommend what is best for you.

It is not known for sure whether rifabutin passes into human breast milk in amounts that could harm a nursing baby. Because the medicine is used in people with serious infections and interacts with many other drugs, your doctor may advise against breastfeeding or may suggest a different treatment.