pharmacopeia
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/api/v1/drug/rifabutin

Mechanism of action

Sourced from openFDA

Rifabutin inhibits DNA-dependent RNA polymerase in susceptible strains of Escherichia coli and Bacillus subtilis but not in mammalian cells. In resistant strains of E.

Nucleic Acid Synthesis

Indications

Sourced from openFDA
  • Rifabutin capsules are indicated for the prevention of disseminated Mycobacterium avium complex (MAC) disease in patients with advanced HIV infection.ICD-10: B20

Contraindications

Sourced from openFDA
  • Rifabutin capsules are contraindicated in patients who have had clinically significant hypersensitivity to rifabutin or to any other rifamycins. Rifabutin capsules are contraindicated in patients being treated with cabotegravir/rilpivirine prolonged-release injectable suspension ( see PRECAUTIONS-Drug Interactions, Table 2 ).contraindicated

Dosage & administration

Sourced from openFDA

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 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.

Warnings & precautions

Sourced from openFDA

Tuberculosis Rifabutin capsules must not be administered for MAC prophylaxis to patients with active tuberculosis. Patients who develop complaints consistent with active tuberculosis while on prophylaxis with rifabutin should be evaluated immediately, so that those with active disease may be given an effective combination regimen of anti-tuberculosis medications. Administration of rifabutin as a single agent to patients with active tuberculosis is likely to lead to the development of tuberculosis that is resistant both to rifabutin and to rifampin. There is no evidence that rifabutin is an effective prophylaxis against M. tuberculosis . Patients requiring prophylaxis against both M. tuberculosis and Mycobacterium avium complex may be given isoniazid and rifabutin concurrently. Tuberculosis in HIV-positive patients is common and may present with atypical or extrapulmonary findings. Patients are likely to have a nonreactive purified protein derivative (PPD) despite active disease. In addition to chest X-ray and sputum culture, the following studies may be useful in the diagnosis of tuberculosis in the HIV-positive patient: blood culture, urine culture, or biopsy of a suspicious lymph node. MAC Treatment with Clarithromycin When rifabutin is used concomitantly with clarithromycin for MAC treatment, a decreased dose of rifabutin is recommended due to the increase in plasma concentrations of rifabutin (see PRECAUTIONS-Drug Interactions, Table 2 ). Hypersensitivity and Related Reactions Hypersensitivity reactions may occur in patients receiving rifamycins.

Adverse reactions

Sourced from openFDA

Adverse Reactions from Clinical Trials Rifabutin capsules were generally well tolerated in the controlled clinical trials. Discontinuation of therapy due to an adverse event was required in 16% of patients receiving rifabutin, compared to 8% of patients receiving placebo in these trials. Primary reasons for discontinuation of rifabutin were rash (4% of treated patients), gastrointestinal intolerance (3%), and neutropenia (2%). The following table enumerates adverse experiences that occurred at a frequency of 1% or greater, among the patients treated with rifabutin in studies 023 and 027. Table: 3 Clinical Adverse Experiences Reported in ≥1% of Patients Treated With Rifabutin Adverse event RIFABUTIN (n = 566) % Placebo (n = 580) % Body as a whole Abdominal pain 4 3 Asthenia 1 1 Chest pain 1 1 Fever 2 1 Headache 3 5 Pain 1 2 Blood and lymphatic system Leucopenia 10 7 Anemia 1 2 Digestive System Anorexia 2 2 Diarrhea 3 3 Dyspepsia 3 1 Eructation 3 1 Flatulence 2 1 Nausea 6 5 Nausea and vomiting 3 2 Vomiting 1 1 Musculoskeletal system Myalgia 2 1 Nervous system Insomnia 1 1 Skin and appendages Rash 11 8 Special senses Taste perversion 3 1 Urogenital system Discolored urine 30 6 CLINICAL ADVERSE EVENTS REPORTED IN <1% OF PATIENTS WHO RECEIVED RIFABUTIN Considering data from the 023 and 027 pivotal trials, and from other clinical studies, rifabutin appears to be a likely cause of the following adverse events which occurred in less than 1% of treated patients: flu-like syndrome, hepatitis, hemolysis, arthralgia, myositis, chest pressure or pain with dyspnea, skin discoloration, th…

Use in specific populations

Sourced from openFDA

Pregnancy Rifabutin should be used in pregnant women only if the potential benefit justifies the potential risk to the fetus. There are no adequate and well-controlled studies in pregnant or breastfeeding women. Reproduction studies have been carried out in rats and rabbits given rifabutin using dose levels up to 200 mg/kg (about 6 to 13 times the recommended human daily dose based on body surface area comparisons). No teratogenicity was observed in either species. In rats, given 200 mg/kg/day, (about 6 times the recommended human daily dose based on body surface area comparisons), there was a decrease in fetal viability. In rats, at 40 mg/kg/day (approximately equivalent to the recommended human daily dose based on body surface area comparisons), rifabutin caused an increase in fetal skeletal variants. In rabbits, at 80 mg/kg/day (about 5 times the recommended human daily dose based on body surface area comparisons), rifabutin caused maternotoxicity and increase in fetal skeletal anomalies. Because animal reproduction studies are not always predictive of human response, rifabutin should be used in pregnant women only if the potential benefit justifies the potential risk to the fetus.

Pharmacokinetics

Sourced from openFDA
Metabolism
Absorption: Following a single oral dose of 300 mg to nine healthy adult volunteers, rifabutin was readily absorbed from the gastrointestinal tract with mean (±SD) peak plasma levels (C max ) of 375 (±267) ng/mL (range: 141 to 1033 ng/mL) attained in 3.3 (±0.9) hours (T max range: 2 to 4 hours). Absolute bioavailability assessed in five HIV-positive patients, who received both oral and intravenous doses, averaged 20%.

Overdosage

Sourced from openFDA

No information is available on accidental overdosage in humans. Treatment While there is no experience in the treatment of overdose with rifabutin capsules, clinical experience with rifamycins suggests that gastric lavage to evacuate gastric contents (within a few hours of overdose), followed by instillation of an activated charcoal slurry into the stomach, may help absorb any remaining drug from the gastrointestinal tract. Rifabutin is 85% protein bound and distributed extensively into tissues (Vss:8 to 9 L/kg). It is not primarily excreted via the urinary route (less than 10% as unchanged drug); therefore, neither hemodialysis nor forced diuresis is expected to enhance the systemic elimination of unchanged rifabutin from the body in a patient with an overdose of rifabutin.

Approval history

Sourced from openFDA
  • Dec 23, 1992NDANDA050689Pfizer
  • Nov 1, 2019NDANDA213004Talicia Holdings
  • Dec 17, 2021ANDAANDA215041Novitium Pharma
  • Mar 19, 2026ANDAANDA212430I3 Pharms

FAERS reports

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Reference statistics only. FAERS reports are voluntarily submitted and are not incidence rates, safety signals, or causal evidence. Counts reflect reporting volume — how often a reaction was reported, not how often it occurs. For decision-grade use, consult openFDA and the FAERS Public Dashboard directly.
2,836 total reports matchedLatest report Share = reports listing the reaction ÷ total matched reports. Rows can sum to >100% because a single report often lists multiple reactions.
  1. 1Drug Ineffective28610%
  2. 2Drug Interaction2538.9%
  3. 3Off Label Use2097.4%
  4. 4Nausea1726.1%
  5. 5Drug Resistance1605.6%
  6. 6Pyrexia1595.6%
  7. 7Mycobacterium Avium Complex Infection1465.1%
  8. 8Drug Intolerance1254.4%
  9. 9Neutropenia1164.1%
  10. 10Immune Reconstitution Inflammatory Syndrome1134.0%
  11. 11Product Use In Unapproved Indication1103.9%
  12. 12Treatment Failure1023.6%
  13. 13Vomiting1023.6%
  14. 14Diarrhoea1013.6%
  15. 15Fatigue923.2%

Literature

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Recent PubMed references pinned to Rifabutin as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

Clinical trials

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The 10 most recently updated of 95 ClinicalTrials.gov registrations naming Rifabutin as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

Frequently asked questions

How does Rifabutin work?
Rifabutin inhibits DNA-dependent RNA polymerase in susceptible strains of Escherichia coli and Bacillus subtilis but not in mammalian cells. In resistant strains of E.
What is Rifabutin used for?
According to FDA labeling, Rifabutin carries indications including: Rifabutin capsules are indicated for the prevention of disseminated Mycobacterium avium complex (MAC) disease in patients with advanced HIV infection.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
What class of drug is Rifabutin?
Rifabutin is classified as Antibiotics, Rifamycin Antimycobacterial, Nucleic Acid Synthesis Inhibitors, Cellular Growth Phase Reduction, Decreased Protein Synthesis, Decreased Transcription to RNA.
What are the brand names for Rifabutin?
Rifabutin is marketed under brand names including Mycobutin, Talicia.
What are the contraindications for Rifabutin?
Rifabutin labeling lists contraindications including: Rifabutin capsules are contraindicated in patients who have had clinically significant hypersensitivity to rifabutin or to any other rifamycins. Rifabutin capsules are contraindicated in patients being treated with cabotegravir/rilpivirine prolonged-release injectable suspension ( see PRECAUTIONS-Drug Interactions, Table 2 ).. Always consult the full prescribing information and a clinician.
Note. Data for rifabutin is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.

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