What is the recommended dose and frequency of Rifampin (Rifampicin)?

From the Guidelines

Rifampin should be dosed at 10 mg/kg daily, not exceeding 600 mg per day, for both adults and children, as recommended by the most recent and highest quality study 1. The recommended dosage of rifampin varies based on weight, with adults weighing more than 50 kg typically receiving 600 mg once daily, and those weighing less than 50 kg receiving 10 mg/kg daily.

• For children, the recommended dose is 10-20 mg/kg daily, not exceeding 600 mg per day, as stated in the study 1.
• Rifampin is usually taken on an empty stomach, at least 1 hour before or 2 hours after meals, to ensure optimal absorption.
• The duration of treatment depends on the specific condition being treated, with tuberculosis typically requiring a multi-drug regimen lasting 6-9 months, latent tuberculosis infection requiring 4 months of monotherapy or 3 months in combination with isoniazid, and MRSA decolonization requiring a shorter course of 5-10 days.
• It is essential to note that rifampin induces cytochrome P450 enzymes, potentially decreasing the effectiveness of many medications, including oral contraceptives, warfarin, and antiretrovirals, so drug interactions should be carefully monitored, as mentioned in the study 1.
• Patients should also be informed that rifampin will cause orange-red discoloration of body fluids, including urine, tears, and sweat. The studies 1, 1, and 1 provide evidence for the recommended dosages and treatment durations, with the most recent study 1 being the highest quality and most relevant to current clinical practice.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Rifampin can be administered by the oral route (see INDICATIONS AND USAGE ). See CLINICAL PHARMACOLOGY for dosing information in patients with renal failure Tuberculosis Adults 10 mg/kg, in a single daily administration, not to exceed 600 mg/day, oral Pediatric Patients 10 to 20 mg/kg, not to exceed 600 mg/day, oral It is recommended that oral rifampin be administered once daily, either 1 hour before or 2 hours after a meal with a full glass of water. Meningococcal Carriers Adults: For adults, it is recommended that 600 mg rifampin be administered twice daily for two days Pediatric Patients: Pediatric patients 1 month of age or older: 10 mg/kg (not to exceed 600 mg per dose) every 12 hours for two days.

The recommended dose and frequency of rifampin are as follows:

• For tuberculosis:
  • Adults: 10 mg/kg, once daily, not to exceed 600 mg/day
  • Pediatric patients: 10 to 20 mg/kg, once daily, not to exceed 600 mg/day
• For meningococcal carriers:
  • Adults: 600 mg, twice daily, for two days
  • Pediatric patients:
    • 1 month of age or older: 10 mg/kg (not to exceed 600 mg per dose), every 12 hours, for two days
    • under 1 month of age: 5 mg/kg, every 12 hours, for two days 2

From the Research

Rifampin Dose and Frequency

• The standard treatment for latent tuberculosis infection (LTBI) includes daily rifampin for 4 months 3.
• Rifampin-based regimens for LTBI have been successful in preventing progression to TB disease, with once-weekly isoniazid and rifapentine for 12 weeks being a recommended option 4.
• Studies have compared the effects of rifampicin monotherapy or rifamycin-combination therapy versus isoniazid monotherapy for preventing active TB in HIV-negative people at risk of developing active TB 5.
• A population-based study found that 4 months of rifampin had lower frequencies of severe hepatic adverse events and higher treatment completion rates compared to 9 months of isoniazid 6.
• A systematic review and meta-analysis found that the 3-month isoniazid-rifapentine regimen is as safe and effective as other recommended LTBI regimens and achieves significantly higher treatment completion rates 7.

Treatment Completion and Safety

• Treatment completion rates were higher for rifampin regimens compared to isoniazid regimens, with a relative risk of 1.19 (95% CI 1.01 to 1.30) 5.
• Rifampicin caused less hepatotoxicity compared to isoniazid, with a relative risk of 0.12 (95% CI 0.05 to 0.30) 5.
• The 3-month isoniazid-rifapentine regimen was associated with similar risk to other LTBI regimens for adverse events, discontinuing treatment because of adverse events, and death 7.

Comparison of Regimens

• Rifampicin monotherapy for 3-4 months was compared to isoniazid monotherapy for 6-9 months, with rifampicin having higher treatment completion rates and less hepatotoxicity 5.
• The 3-month isoniazid-rifapentine regimen was compared to other LTBI regimens, including 9-month isoniazid treatment, and found to be equally effective and have higher treatment completion rates 7.