What Is Rifampicin?
Rifampicin, also known as rifampin, is an antibiotic with the chemical formula C43H58N4O12 and a molecular weight of 822.94. It appears as a reddish-brown to orange-red crystal or crystalline powder. Rifampicin is insoluble in water, acetonitrile, methanol, and ethanol, but is soluble in chloroform.
It is known for its broad-spectrum antibacterial activity against both Gram-positive and Gram-negative bacteria. Rifampicin is primarily used to treat infections such as tuberculosis and leprosy. It is often used in combination with other antituberculosis drugs to prevent the development of drug resistance.
Rifampicin is produced by semi-synthesis from rifamycin, a compound produced by the actinomycete Streptomyces mediterranei.
Uses of Rifampicin
Rifampicin is used as an antibiotic to treat various bacterial infections, including pulmonary tuberculosis, non-tuberculous mycobacteriosis, and leprosy. It works by inhibiting bacterial RNA synthesis, targeting RNA polymerase.
Common side effects of rifampicin include renal failure, interstitial nephritis, shock, anaphylaxis, nausea, stomach pain, vomiting, anorexia, and diarrhea.
Properties of Rifampicin
Rifampicin is a yellow-orange crystalline powder with poor solubility in water but solubility in alcohol and acetone. It is sensitive to heat and light, requiring careful storage. Rifampicin exhibits potent activity against Mycobacterium tuberculosis and other bacteria.
- Mode of Action: Rifampicin inhibits bacterial RNA transcription by acting on RNA polymerase, thereby stopping bacterial growth.
- Antimicrobial Resistance: To minimize the emergence of resistant strains, rifampicin is usually combined with other antituberculosis drugs.
- Pharmacokinetics: Rifampicin is rapidly absorbed from the gastrointestinal tract after oral administration, with peak blood levels reached within 2-4 hours. It is metabolized in the liver and excreted primarily in urine.
- Side Effects: Common side effects include liver damage, jaundice, rash, fever, and gastrointestinal symptoms. Serious side effects are rare but can include allergic reactions and liver damage.
Structure of Rifampicin
Rifampicin has a complex structure featuring a naphthoquinone skeleton, an ansamycin ring, and a piperazine acid-bonded structure. The ansamycin ring contributes to its lipophilicity and facilitates passage through bacterial cell membranes, while the piperazine acid moiety is the active site that targets bacterial RNA polymerase.
Other Information on Rifampicin
Manufacturing Process of Rifampicin
Rifampicin was originally isolated from the actinomycete Streptomyces mediterranei. Current production methods include both biological and chemical semi-synthetic processes. The most common method involves culturing Streptomyces mediterranei and extracting and purifying rifampicin from the culture medium.