Rifampicin

Mechanism :

Rifampin inhibits DNA-dependent RNA polymerase activity in susceptible cells. Specifically, it interacts with bacterial RNA polymerase but does not inhibit the mammalian enzyme. Rifampin at therapeutic levels has demonstrated bactericidal activity against both intracellular and extracellular Mycobacterium tuberculosis organisms.

Indication :

• Tuberculosis
• Staphylococcal infections
• Meningococcal Infection prophylaxis
• H influenza prophylaxis (off-label)
• Cholestasis - pruritus

Contraindications :

Rifampin is contraindicated in patients with a history of hypersensitivity to any of the rifamycin’s.

Dosing :

Adverse Effect :

Anorexia, nausea, vomiting, abdominal discomfort, diarrhea, pseudo-membranous colitis, flushing, urticaria, rash, red man syndrome, orange discoloration of urine and body fluids, discoloration of the contact lenses, thrombocytopenia with or without purpura, leukopenia, eosinophilia. Immunological reactions: flu-like symptoms, with chills, fever, dizziness, bone pain, shortness of breath and wheezing, acute hemolytic anemia, acute renal failure and thrombocytopenic purpura, alterations of liver function. Miscellaneous: edema, muscular weakness, and menstrual disturbances.

Interaction :

Anticonvulsants, Antiarrhythmics, Oral Anticoagulants, Antifungals, Itraconazole, Ketoconazole, Barbiturates, Beta-Blockers, Calcium Channel Blockers Diltiazem, Nifedipine, Verapamil, Chloramphenicol, Clarithromycin, Corticosteroids, Cyclosporine, Cardiac Glycoside Preparations, Clofibrate, Oral or other Systemic Hormone Contraceptives, Dapsone, Diazepam, Doxycycline, Fluoroquinolones, Haloperidol, Oral Hypoglycemic Agents (Sulfonylureas), Levothyroxine, Methadone, Narcotic Analgesics, Nortriptyline, Progestins, Quinine, Tacrolimus, Theophylline Tricyclic Antidepressants (e.g., Amitriptyline, Nortriptyline), and Zidovudine: Rifampin has been reported to accelerate the metabolism.
Oral or other Systemic Hormonal Contraceptives: Should be advised to change to nonhormonal methods of birth control during rifampin therapy.
Anticoagulant Drugs of the Coumarin Type: It is recommended that the prothrombin time be performed daily or as frequently as necessary to establish and maintain the required dose of anticoagulant.
Ketoconazole: Concurrent use of ketoconazole and rifampin has resulted in decreased serum concentrations of both drugs.
Enalapril: Concurrent use of rifampin and enalapril has resulted in decreased concentrations of enalaprilat, the active metabolite of enalapril.
Concomitant antacid administration may reduce the absorption of rifampin.
Probenecid and Cotrimoxazole: have been reported to increase the blood level of rifampin
Halothane or Isoniazid: The potential for hepatotoxicity is increased. The concomitant use of rifampin and halothane should be avoided. Patients receiving both rifampin and isoniazid should be monitored close for hepatotoxicity.
Sulfapyridine: Plasma concentrations of sulfapyridine may be reduced following the concomitant administration of sulfasalazine and rifampin.

Renal Dose :

Hepatic Dose :