Rifabutin
Rifabutin is an antibiotic taken by mouth to help prevent a serious bacterial infection called disseminated Mycobacterium avium complex (MAC) disease in people with advanced HIV infection.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 7 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Rifabutin (Mycobutin), a rifamycin antibiotic on the market since the early 1990s and available as a generic, helps prevent disseminated MAC (a bacterial infection that spreads through the body) in people with advanced HIV, usually as a backup to azithromycin or clarithromycin. Most people tolerate it well; the usual complaints are nausea, indigestion and taste changes, and urine often turns orange-brown, which is harmless. The big concern is tuberculosis, which rifabutin does not prevent and, used alone, can make resistant to both rifabutin and rifampin, so active TB must be ruled out first. It also clashes with many HIV medicines, so any regimen change needs a fresh interaction check.
Clinical pearls
- Eye pain, redness or vision changes can signal uveitis (eye inflammation), more likely if clarithromycin or fluconazole is also taken.
- HIV protease inhibitors such as ritonavir or darunavir raise rifabutin levels, so the rifabutin dose is usually lowered.
- Severe or lasting diarrhea, even two months after stopping, can mean C. diff, a serious antibiotic-linked bowel infection, so call promptly.
- Hives, swelling, wheezing or blistering skin need urgent care, and a past serious reaction to rifampin means avoiding rifabutin.
Patient information guide A plain-language walkthrough of Rifabutin, written from its FDA label.
What Rifabutin is used for
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Rifabutin is used for one preventive purpose.
- Rifabutin capsules (oral) prevent disseminated Mycobacterium avium complex (MAC) disease in people with advanced HIV infection.
How Rifabutin works
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Rifabutin is a rifamycin antibiotic. In lab studies of certain bacteria, it blocked an enzyme (DNA-dependent RNA polymerase) bacteria need to make RNA, and it did not block that enzyme in mammalian cells.
Whether it blocks this enzyme in the MAC bacteria is not known. Bacteria resistant to rifampin were also not affected by rifabutin in lab testing.
Rifabutin dosage
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Rifabutin capsules are taken by mouth, usually once a day. If you tend to get nausea, vomiting or other stomach upset, your prescriber may have you take it in two smaller doses with food.
- The capsule contents can be mixed with foods such as applesauce.
- People with severe kidney disease may need a lower dose if toxicity is suspected.
- Dose changes may also be needed with certain other drugs.
Follow your prescriber's directions and the label. Ask your pharmacist what to do if you miss a dose.
Dosing details from the FDA-approved label
From the Rifabutin prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- General recommended dosing (adults)
- 300 mg once daily
- Capsule doses may be administered mixed with foods such as applesauce
- Patients with propensity to nausea, vomiting, or other gastrointestinal upset
- 150 mg twice daily taken with food
- Taken with food
- Severe renal impairment (creatinine clearance less than 30 mL/min)
- Consider reducing the dose of rifabutin by 50%, if toxicity is suspected
- No dosage adjustment required for mild to moderate renal impairment
- Hepatic impairment
- Mild hepatic impairment does not require a dose modification
- Pharmacokinetics in moderate and severe hepatic impairment is not known
Read the label’s full dosing text
DOSAGE AND ADMINISTRATION It is recommended that rifabutin capsules be administered at a dose of 300 mg once daily. For those patients with propensity to nausea, vomiting, or other gastrointestinal upset, administration of rifabutin at doses of 150 mg twice daily taken with food may be useful. Doses of Rifabutin capsules may be administered mixed with foods such as applesauce. For patients with severe renal impairment (creatinine clearance less than 30 mL/min), consider reducing the dose of rifabutin by 50%, if toxicity is suspected. No dosage adjustment is required for patients with mild to moderate renal impairment. Reduction of the dose of rifabutin may also be needed for patients receiving concomitant treatment with certain other drugs (see PRECAUTIONS-Drug Interactions ). Mild hepatic impairment does not require a dose modification. The pharmacokinetics of rifabutin in patients with moderate and severe hepatic impairment is not known.
Read the full Dosage and Administration section on DailyMed →
Rifabutin side effects
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Rifabutin was generally well tolerated in clinical trials, but some people stopped it because of side effects.
Common side effects
- Rash
- Discolored urine (very common)
- Low white blood cell count (leucopenia)
- Nausea, or nausea with vomiting
- Abdominal pain
- Indigestion, belching or gas
- Changes in taste
- Diarrhea
- Muscle aches and fever
When to get medical help
- Signs of an allergic reaction: low blood pressure, hives, swelling, wheezing, fever, chills, aches, or trouble breathing. Get help right away.
- A skin rash that spreads or gets worse, or blistering or peeling skin. These can be severe skin reactions. Call your doctor right away.
- Eye pain, redness or vision changes, which can signal uveitis (eye inflammation).
- Diarrhea that is severe or persistent, even up to two months or more after treatment.
- Symptoms that could mean active tuberculosis. Tell your doctor right away so you can be evaluated.
Rifabutin warnings and precautions
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- Tuberculosis: do not use for MAC prevention if you have active tuberculosis. Rifabutin alone can lead to drug-resistant tuberculosis and does not prevent it.
- Allergic reactions: including anaphylaxis, have been reported with rifamycins. Rifabutin should be stopped if they occur.
- Uveitis: eye inflammation is more of a concern with clarithromycin, other macrolides, or fluconazole. Eye pain or vision changes need an eye specialist's evaluation.
- C. difficile diarrhea: can range from mild to fatal and can appear months after antibiotics.
- Severe skin reactions: such as Stevens-Johnson syndrome and DRESS. Rifabutin should be stopped if lesions progress.
Rifabutin interactions
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Rifabutin interacts with many medicines, so your prescriber and pharmacist should review everything you take.
- Cabotegravir/rilpivirine injection, delavirdine and voriconazole: contraindicated.
- HIV protease inhibitors: raise rifabutin levels, often requiring at least a 50% rifabutin dose reduction.
- Clarithromycin and fluconazole: raise rifabutin levels and the risk of side effects and uveitis.
- Itraconazole, posaconazole, clarithromycin, saquinavir: rifabutin can lower their levels.
- Bictegravir, elvitegravir, oral rilpivirine, doravirine and sofosbuvir: rifabutin may lower levels, so use is not recommended or doses may need adjusting.
Interactions listed in the FDA-approved label
From the Rifabutin prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Delavirdine: Rifabutin AUC increased by 230% and Cmax by 128%; delavirdine AUC decreased by 80%, Cmax by 75%, Cmin by 17%. CONTRAINDICATED
- Voriconazole: Rifabutin AUC increased by 331% and Cmax by 195%; voriconazole AUC and Cmax each increased by ~100% compared to voriconazole 200 mg twice a day alone. CONTRAINDICATED
- Amprenavir: Rifabutin AUC increased by 193% and Cmax by 119%. Reduce rifabutin dose by at least 50%. Monitor closely for adverse reactions.
- Atazanavir/Ritonavir: Rifabutin AUC increased 48% and Cmax 149%; 25-O-desacetyl-rifabutin AUC increased 990% and Cmax 677%. Reduce rifabutin dose to 150 mg every other day or 3 times a week. Increased monitoring for adverse reactions is warranted.
- Bictegravir (Biktarvy): Bictegravir AUC decreased 38%, Cmin 56%, Cmax 20%; decrease in tenofovir alafenamide expected. Co-administration with Biktarvy is not recommended.
- Elvitegravir/Cobicistat: 25-O-desacetyl-rifabutin AUC increased 6.3-fold and Cmax 4.8-fold; elvitegravir Ctrough decreased 67%. Co-administration is not recommended due to expected decrease in elvitegravir exposure.
- Sofosbuvir: Sofosbuvir Cmax decreased 36 and AUC 24. Co-administration of rifabutin with sofosbuvir (alone or in combination) is not recommended.
- Fluconazole: Rifabutin AUC increased by 82% and Cmax by 88%. Monitor for rifabutin associated adverse events. Reduce rifabutin dose or suspend use if toxicity is suspected.
- Itraconazole: Itraconazole AUC decreased by 70% and Cmax by 75%; one case of uveitis was associated with increased rifabutin levels. If co-administration cannot be avoided, monitor for rifabutin adverse events and lack of itraconazole efficacy.
- Zidovudine: Zidovudine AUC decreased by 32% and Cmax by 48%; levels remained within therapeutic range. Dosage adjustments are not necessary.
Read the label’s full interactions text
Drug Interactions Effect of Rifabutin on the Pharmacokinetics of Other Drugs: Rifabutin induces CYP3A enzymes and therefore may reduce the plasma concentrations of drugs metabolized by those enzymes. This effect may reduce the efficacy of standard doses of such drugs, which include itraconazole, clarithromycin, and saquinavir. Effect of Other Drugs on Rifabutin Pharmacokinetics: Some drugs that inhibit CYP3A may significantly increase the plasma concentration of rifabutin. Therefore, carefully monitor for rifabutin associated adverse events in those patients also receiving CYP3A inhibitors, which include fluconazole and clarithromycin. In some cases, the dosage of rifabutin may need to be reduced when it is coadministered with CYP3A inhibitors. Table 2 summarizes the results and magnitude of the pertinent drug interactions assessed with rifabutin. The clinical relevance of these interactions and subsequent dose modifications should be judged in light of the population studied, severity of the disease, patient's drug profile, and the likely impact on the risk/benefit ratio. Table 2 Rifabutin Interaction Studies Coadministered drug Dosing regimen of coadministered drug Dosing regimen of rifabutin Study population (n) Effect on rifabutin Effect on coadministered drug Recommendation ANTIRETROVIRALS Amprenavir 1200 mg twice a day for 10 days 300 mg once a day for 10 days Healthy male subjects (6) ↑ AUC by 193%, ↑ C max by 119% ↔ Reduce rifabutin dose by at least 50%. Monitor closely for adverse reactions. Atazanavir/Ritonavir 300/100 mg once daily 150 mg twice weekly Healthy adult subjects 48% ↑ in AUC, 149% ↑ C max of rifabutin. 990% ↑ in AUC, 677% ↑ C max of 25-O-desacetyl-rifabutin. No significant change in pharmacokinetics. A reduction in the dose of rifabutin (to 150 mg every other day or 3 times a week) is recommended. Increased monitoring for adverse reactions is warranted.
Excerpted — the section continues on the label. Read the full Drug Interactions section on DailyMed →
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Rifabutin
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- Do not use with a history of significant allergy to rifabutin or other rifamycins.
- Tell your doctor if you may have active tuberculosis.
- Severe kidney disease may call for a dose reduction; mild to moderate kidney disease does not.
- Mild liver impairment needs no change; effects in moderate or severe impairment are unknown.
- Levels vary more in people over 70.
- Not studied in people under 18.
Rifabutin overdose
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No information is available on accidental overdose in humans. Overdose care may involve emptying the stomach within a few hours, followed by activated charcoal. Dialysis and forced urine output are not expected to help. Seek emergency help or call poison control.
How your body processes Rifabutin
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Rifabutin is absorbed from the gut, with peak levels about 2 to 4 hours after a dose. High-fat meals slow absorption but do not change how much is absorbed. It spreads widely into tissues, including the lungs.
Its half-life is long, averaging about 45 hours. The body breaks it down into metabolites, one as active as the parent drug. Most is cleared in urine (mostly as metabolites), and about 30% in feces. Kidney impairment raises drug levels.
How to store Rifabutin
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dispense in a tight container as defined in the USP. Store at 25°C (77°F); excursions permitted to 15°–30°C (59°–86°F) .
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Supplements & herbs that interact with Rifabutin
180 supplements and herbal products have documented interactions with Rifabutin in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 3
- Moderate · 136
- Minor · 41
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Nutrient depletion considerations
Rifabutin has been associated with lower levels of 7 nutrients in the clinical literature. This does not mean a deficiency will occur — it means these may be worth discussing with your pharmacist or healthcare provider, especially with long-term use.
- Higher significance · 6
- Moderate · 1
Educational information from a licensed clinical database (Natural Medicines) — not medical advice. Do not start or stop medications or supplements without professional guidance.
Rifabutin: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Rifabutin — the kind of thing our pharmacy team would talk through with you at the counter.
What is rifabutin for?
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How should I take it?
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My urine changed color. Should I worry?
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What side effects should I call about?
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Can I take it with my other medicines?
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Is Rifabutin available over the counter?
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When was Rifabutin first available?
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Who makes Rifabutin?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Rifabutin on HelloPharmacist
Rifabutin forms and strengths (how it comes)
Rifabutin is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Capsule
How this form is used
- Rifabutin capsules are used to prevent disseminated MAC disease in people with advanced HIV infection.
- Rifabutin capsules are generally taken once daily by mouth.
- Rifabutin capsules may be taken as two smaller doses with food if stomach upset is a problem.
- Rifabutin capsule contents may be mixed with food such as applesauce.
Rifabutin on the U.S. market: products, makers and brands
How Rifabutin appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
6 companies list 7 Rifabutin product records with the FDA, mostly as capsule; the earliest marketing or approval year on record is 1992. Brand names on the directory include Mycobutin; the rest are generics.
Also listed with the FDA, not a patient dose form: Powder (1) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
How widely Rifabutin is used (Medicaid data)
A general measure of how commonly Rifabutin is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Rifabutin is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Rifabutin prescribed? Of the 1,601 medications we measure, Rifabutin ranks #976 by Medicaid prescriptions — more than 39% of them.
Utilization by Rifabutin product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
rifabutin 150 MG Oral Capsule
Summed across the 2 of 13 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 198200
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Rifabutin, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 2 of 13 listed Rifabutin NDCs with Medicaid activity.
Compare Rifabutin products
A representative set of FDA-listed product records for Rifabutin — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Capsule | ||||
| 150 mg | Oral | A2A Integrated Pharmaceuticals | ANDA | View NDC → |
| 150 mg | Oral | ANI Pharmaceuticals, Inc. | ANDA | View NDC → |
| 150 mg | Oral | i3 Pharmaceuticals, LLC | ANDA | View NDC → |
| 150 mg | Oral | Marlex Pharmaceuticals, Inc. | ANDA | View NDC → |
| 150 mg | Oral | Mylan Pharmaceuticals Inc. | NDA AUTHORIZED GENERIC | View NDC → |
| 150 mg | Oral | Remedyrepack Inc. | NDA AUTHORIZED GENERIC | View NDC → |
| 150 mg | Oral | Remedyrepack Inc. | ANDA | View NDC → |
Showing 7 of 7 products — FDA National Drug Code Directory. See every product, package size and price: browse all 7 Rifabutin NDCs →
Rifabutin side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Rifabutin — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Rifabutin in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Rifabutin FDA approval history
How Rifabutin went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
Rifabutin recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Rifabutin recalls since July 2021.
✅No Rifabutin recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 55672 1 dose form · 1 strength
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Dose form (SCDF) Oral Capsule RxCUI 373780In current FDA listingsClinical drug / strength (SCD) 150 MGRxCUI 198200
Look up RxCUI 55672 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Rifabutin supply and shortage status
Whether Rifabutin is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
Rifabutin brand names
Rifabutin is sold under one brand name in the FDA directory — Mycobutin. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Rifabutin: manufacturers and labelers
6 companies list Rifabutin products with the FDA. By number of product records, the largest are Remedyrepack Inc., A2A Integrated Pharmaceuticals, ANI Pharmaceuticals, Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Rifabutin drug class (RxNorm)
Rifabutin belongs to the Rifamycin Antimycobacterial class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Rifabutin page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Remedyrepack Inc. is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →