-2%
Rifampicin is a bactericidal antibiotic that inhibits bacterial RNA synthesis. It acts by binding specifically to the β-subunit of DNA-dependent RNA polymerase in susceptible microorganisms, thereby preventing RNA transcription and suppressing bacterial protein synthesis.
Rifcin is indicated for the treatment of all forms of tuberculosis (TB) and for the eradication of the meningococcal carrier state. During treatment of tuberculosis or meningococcal carriage, a small population of naturally resistant bacteria may rapidly multiply and become dominant. Therefore, bacteriological cultures and susceptibility testing should be performed before initiating therapy and repeated periodically throughout treatment to assess clinical response and detect emerging resistance.
If cultures remain positive or resistance to rifampicin is confirmed, and the patient shows inadequate clinical improvement, the treatment regimen should be revised accordingly.
Use this medicine only under the supervision of a registered physician.
Rifampicin may be administered orally or by intravenous infusion. The IV dose is equivalent to the recommended oral dose.
Tuberculosis
Adults
- 10 mg/kg once daily.
- Maximum daily dose: 600 mg.
Children
- 10–20 mg/kg once daily.
- Maximum daily dose: 600 mg.
For optimal absorption, oral rifampicin should be taken on an empty stomach, either 1 hour before or 2 hours after meals, with a full glass of water.
Recommended Treatment Regimen
For newly diagnosed tuberculosis, rifampicin should be used as part of a multidrug regimen. Initial therapy generally consists of:
- Rifampicin
- Isoniazid
- Pyrazinamide
This intensive phase usually continues for 2 months.
Depending on the likelihood of isoniazid resistance, a fourth drug, such as ethambutol or streptomycin, may be included until susceptibility test results become available.
Following the intensive phase, treatment should continue with rifampicin and isoniazid for at least 4 additional months. A longer duration may be required in patients with persistent positive sputum cultures, drug-resistant organisms, or HIV infection.
Rifampicin is a potent inducer of hepatic CYP450 enzymes and may significantly alter the metabolism of many medications.
It may:
- Reduce the effectiveness of drugs metabolized by CYP450 enzymes, including quinidine, phenytoin, and theophylline.
- Decrease plasma concentrations of atovaquone and enalaprilat.
- Lower serum levels of ketoconazole are seen when used concurrently.
- Reduce rifampicin absorption when administered with antacids.
- Increase the risk of liver toxicity when combined with hepatotoxic agents such as isoniazid or halothane.
Rifcin should not be used in patients who:
- Have a known hypersensitivity to rifampicin, rifamycins, or any formulation component.
- Are receiving ritonavir-boosted saquinavir due to a significantly increased risk of severe hepatocellular toxicity.
- Are taking atazanavir, darunavir, fosamprenavir, saquinavir, or tipranavir, as rifampicin markedly reduces the plasma concentrations of these antiviral agents, potentially leading to treatment failure and antiviral resistance.
Common Adverse Effects
- Flushing of the face
- Itching, with or without skin rash
- Flu-like symptoms including fever, chills, headache, dizziness, malaise, bone pain, and shortness of breath
- Nausea
- Vomiting
- Loss of appetite
- Diarrhea
- Epigastric discomfort
- Orange-red discoloration of urine, saliva, sweat, sputum, tears, and feces
Less Common or Serious Reactions
- Pseudomembranous colitis
- Eosinophilia
- Leukopenia
- Hemolytic anemia
- Renal impairment or renal failure
- Menstrual irregularities
- Edema
- Myopathy and muscle weakness
- Thrombophlebitis following prolonged IV infusion
- Local injection site irritation
- Visual disturbances
- Severe allergic reactions, including anaphylaxis and shock (rare)
Pregnancy
Administration during the final weeks of pregnancy may increase the risk of postpartum hemorrhage in both mother and newborn. Vitamin K supplementation may be considered when clinically appropriate.
Breastfeeding
Because animal studies have demonstrated a potential risk of tumor formation, healthcare providers should carefully weigh the benefits of continued breastfeeding against the mother’s need for rifampicin therapy.
Rifampicin has been associated with serious liver toxicity, including fatal hepatitis. Patients with pre-existing liver disease or those receiving other hepatotoxic medications require careful monitoring.
Before starting therapy, baseline liver function tests, including ALT (SGPT) and AST (SGOT), should be obtained and repeated every 2–4 weeks during treatment. Rifampicin should be discontinued if significant hepatocellular injury develops.
Transient elevations in bilirubin may occur early in therapy due to competition between rifampicin and bilirubin for hepatic excretion. Mild isolated increases in bilirubin or liver enzymes do not necessarily require discontinuation but should be reassessed with repeat laboratory testing and correlated with the patient’s clinical status.
Rifampicin also induces several hepatic enzymes, including delta-aminolevulinic acid synthetase, and has occasionally been associated with exacerbation of porphyria.
Symptoms of overdose may include:
- Nausea and vomiting
- Severe abdominal pain
- Pruritus
- Headache
- Drowsiness progressing to lethargy
- Orange-red or brown discoloration of the skin and body fluids
- Elevated liver enzymes and bilirubin
- Hepatomegaly with tenderness
- Jaundice
- Facial or periorbital edema (particularly in children)
- Hypotension
- Sinus tachycardia
- Ventricular arrhythmias
- Seizures
- Cardiac arrest in severe or fatal cases
Prompt medical management and supportive care are essential.
Reconstitute the vial containing 600 mg of lyophilized rifampicin powder with 10 mL of sterile water for injection. Gently swirl until completely dissolved to obtain a solution containing 60 mg/mL.
Withdraw the calculated dose and further dilute it in:
- 500 mL infusion fluid for administration over approximately 3 hours, or
- 100 mL infusion fluid for administration over approximately 30 minutes.
Dilutions prepared in 5% dextrose injection (D5W) remain stable for up to 8 hours at room temperature. Solutions prepared in normal saline should be used within 6 hours. Other infusion fluids are not recommended due to compatibility concerns.
Store between 15°C and 30°C in a dry place. Protect from excessive heat and direct light.
