Rifampin (oral)

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Rifampin
FDA Package Insert (Rifadin®)
Description
Clinical Pharmacology
Microbiology
Indications and Usage
Contraindications
Warnings and Precautions
Adverse Reactions
Overdosage
Dosage and Administration
How Supplied
Labels and Packages

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Chetan Lokhande, M.B.B.S [2]

Overview

Rifampin was introduced in 1967,[1] as a major addition to the cocktail-drug treatment of tuberculosis and inactive meningitis, along with pyrazinamide, isoniazid, ethambutol and streptomycin ("PIERS"). It requires a prescription in North America. It must be administered regularly daily for several months without break; otherwise, the risk of drug-resistant tuberculosis is greatly increased.[1] In fact, this is the primary reason it is used in tandem with the three aforementioned drugs, particularly isoniazid.[2] This is also the primary motivation behind directly observed therapy for tuberculosis.

Category

Antimycobacterial

US Brand Names

RIFADIN®

FDA Package Insert

Description | Clinical Pharmacology | Microbiology | Indications and Usage | Contraindications | Warnings and Precautions | Adverse Reactions | Overdosage | Clinical Studies | Dosage and Administration | Compatibility, Reconstitution, and Stability | How Supplied | Labels and Packages

Mechanisms of Action

Rifampin inhibits bacterial DNA-dependent RNA synthesis by inhibiting bacterial DNA-dependent RNA polymerase.[3]

Crystal structure data and biochemical data indicate that rifampicin binds to RNA polymerase at a site adjacent to the RNA polymerase active center and blocks RNA synthesis by physically preventing extension of RNA products beyond a length of 2-3 nucleotides ("steric-occlusion" mechanism).[4][5]

Resistance to rifampin arises from mutations that alter residues of the rifampin binding site on RNA polymerase, resulting in decreased affinity for rifampin.[5] Resistant mutations map to the rpoB gene, encoding RNA polymerase beta subunit.

References

  1. 1.0 1.1 Long, James W. (1991). Essential Guide to Prescription Drugs 1992. New York: HarperCollins Publishers. pp. 925–929. ISBN 0-06-273090-8.
  2. Erlich, Henry, W Ford Doolittle, Volker Neuhoff, and et al. . Molecular Biology of Rifomycin. New York, NY: MSS Information Corporation, 1973. pp. 44-45, 66-75, 124-130.
  3. Calvori, C.; Frontali, L.; Leoni, L.; Tecce, G. (1965). "Effect of rifamycin on protein synthesis". Nature. 207 (995): 417–8. doi:10.1038/207417a0. PMID 4957347.
  4. Campbell, E.A., Korzheva, N., Mustaev, A., Murakami, K., Nair, S., Goldfarb, A., Darst, S.A. (2001). "Structural mechanism for rifampicin inhibition of bacterial RNA polymerase". Cell. 104 (6): 901–12. doi:10.1016/S0092-8674(01)00286-0. PMID 11290327.
  5. 5.0 5.1 Feklistov, A., Mekler, V., Jiang, Q., Westblade, L.F., Irschik, H., Jansen, R., Mustaev, A., Darst, S.A., Ebright, R.H. (2008). "Rifamycins do not function by allosteric modulation of binding of Mg2+ to the RNA polymerase active center". Proc Natl Acad Sci USA. 105 (39): 14820–5. doi:10.1073/pnas.0802822105. PMC 2567451. PMID 18787125.