Reviewed on 9/12/2023

What Is Rifampin and How Does It Work?

Rifampin is a prescription medication used for treatment of both tuberculosis and the meningococcal carrier state. Bacteriologic cultures should be obtained before the start of therapy to confirm the susceptibility of the organism to rifampin and they should be repeated throughout therapy to monitor the response to treatment.

  • Rifampin is available under the following different brand names: Rifadin and Rimactane.

What Are Dosage of Rifampin?

Dosage of Rifampin:

Adult and Pediatric Dosages:


  • 150 mg
  • 300 mg

Injectable Powder

  • 600 mg

Dosage Considerations – Should be Given as Follows:


Adult Dosage:

  • 10 mg/kg/day orally or 10 mg/kg orally twice-weekly (directly observed therapy [DOT]); not to exceed 600 mg/day

Dosing considerations:

  • It may be given in conjunction with isoniazid or with isoniazid or with isoniazid and pyrazinamide
  • Rifampin dosage not to exceed 600 mg/day

Pediatric Dosage:

  • 10-20 mg/kg/day intravenously/orally or 10-20 mg/kg orally twice-weekly (DOT); not to exceed 600 mg/day

Neisseria meningitidis Carrier

Adult Dosage

  • 600 mg every 12 hours for 2 days

Pediatric Dosage


  • Infants 1 month and younger: 10 mg/kg/day orally divided every 12 hours for 2 days
  • Infants older than 1 month: 20 mg/kg/day orally divided every 12 hours for 2 days, not to exceed 600 mg/day

Haemophilus Influenzae Type B Infection

Adult Dosage


  • 600 mg/day orally/intravenously for 4 days

Pediatric Dosage


  • Infants 1 month and younger: 10 mg/kg/day orally for 4 days; not to exceed 600 mg/day

What Are Side Effects Associated with Using Rifampin?

Side effects of rifampin include:

  • heartburn
  • abdominal pain
  • loss of appetite
  • nausea
  • vomiting
  • yellowing skin and eyes (jaundice)
  • gas (flatulence)
  • cramps
  • diarrhea
  • elevated liver function test (LFT) results
  • hepatitis
  • deficiency of platelets in the blood
  • discoloration of the skin
  • brain bleed
  • fatalities
  • abnormal clotting of the blood
  • destruction of red blood cells
  • low red blood cell count
  • headache
  • fever
  • drowsiness
  • fatigue
  • loss of full control of body movements
  • dizziness
  • inability to concentrate
  • mental confusion
  • behavioral changes
  • muscular weakness
  • pain in extremities
  • generalized numbness
  • visual disturbances
  • menstrual disturbances
  • elevated BUN
  • elevated serum uric acid
  • flushing
  • itching
  • rash
  • severe itching
  • hives
  • acute formation of blisters
  • erythema multiforme, including Stevens-Johnson Syndrome
  • toxic epidermal necrolysis
  • inflammation in blood vessels
  • eosinophilia
  • sore mouth
  • sore tongue
  • pink eye
  • acute allergic reaction (anaphylaxis)
  • swelling
  • flu syndrome
  • shortness of breath
  • wheezing
  • decrease in blood pressure
  • shock

Rare side effects of rifampin include:

  • blood in urine
  • inflammation in the kidney
  • lack of blood flow to the kidneys
  • kidney insufficiency
  • acute kidney failure
  • psychoses
  • the disease of muscle tissue
  • adrenal insufficiency, Addison's Disease
  • lowered white blood cell count

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Rifampin?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Rifampin has severe interactions with at least 33 different drugs.
  • Rifampin has serious interactions with at least 159 different drugs.
  • Rifampin has moderate interactions with at least 237 different drugs.
  • Rifampin has mild interactions with at least 67 different drugs.

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns, or for more information about this medicine.

What Are Warnings and Precautions for Rifampin?


This medication contains rifampin. Do not take Rifadin or Rimactane if you are allergic to rifampin or any ingredients contained in this drug.

Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately


  • Hypersensitivity to rifamycins
  • Concomitant administration of live bacterial vaccines
  • Contraindicated in patients receiving ritonavir-boosted saquinavir, because of increased risk of severe hepatocellular toxicity
  • Contraindicated in patients receiving atazanavir, darunavir, fosamprenavir, saquinavir, or tipranavir, because rifampin may cause substantial decreases in plasma concentrations of these antiviral drugs, which may result in loss of antiviral efficacy or development of viral resistance

Effects of Drug Abuse

  • No information available

Short-Term Effects

  • See "What Are Side Effects Associated with Using Rifampin?"

Long-Term Effects

  • Prolonged use may result in bacterial or fungal superinfection
  • See "What Are Side Effects Associated with Using Rifampin?"


  • May decrease the effectiveness of oral contraceptive pills (OCPs)
  • Do not administer parenteral preparation intramuscularly or subcutaneously
  • Patients on regimens of over 600 mg once or twice weekly may experience adverse reactions, including flulike syndrome
  • History of diabetes mellitus (rifampin may make diabetes management more difficult)
  • Regimens of over 600 mg once or twice weekly may cause leukemia, anemia, or thrombocytopenia
  • Discontinue therapy if a patient develops any signs of hepatocellular damage, including hyperbilirubinemia
  • Prolonged use may result in bacterial or fungal superinfection
  • Use with caution in patients with liver impairment and porphyria
  • Not for use in meningococcal disease; may be suitable for short-term use in asymptomatic carriers
  • Use with caution in patients with a history of alcoholism and patients receiving additional medications that may cause hepatotoxicity
  • Rifampin is not recommended for intermittent therapy; caution patient against intentional or accidental interruption of daily dosage regimen; rare renal hypersensitivity reactions have been reported when therapy was resumed in such cases
  • Rifampin has enzyme-inducing properties that can enhance the metabolism of endogenous substrates, including adrenal hormones, thyroid hormones, and vitamin D

Pregnancy and Lactation

  • Use rifampin during pregnancy with caution if benefits outweigh risks
  • Animal studies show risk and human studies are not available, or neither animal nor human studies were done
  • Effects of rifampin during pregnancy are unknown
  • It is reported to cross the placental barrier and appear in cord blood; increased congenital malformations, primarily spina bifida and cleft palate reported in offspring of rodents given oral doses of 150-250 mg/kg/day during pregnancy; case reports of postnatal hemorrhage in mother and infant when administered during last few weeks of pregnancy
  • Rifampin enters breast milk; consult with your physician if breastfeeding
Medscape. Rifampin.
RxList. Rifampin Monograph.

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