The rifamycins are bactericidal antibiotics; they inhibit bacterial DNA-dependent RNA polymerase, suppressing RNA synthesis. The following drugs are rifamycins:
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Rifabutin, Rifampin, and Rifapentine
Pharmacokinetics
Oral absorption is good, producing wide distribution in body tissues and fluids, including cerebrospinal fluid.
Indications
is active against
Most gram-positive and some gram-negative bacteria
Mycobacterium species
mycobacteria, such as Mycobacterium fortuitum, M. chelonae, or M. abscessus, are naturally resistant)
Staphylococcal infections, including osteomyelitis, prosthetic valve endocarditis, and infections involving foreign bodies such as a prosthetic joint (with other antistaphylococcal antibiotics)
Pneumococcal meningitis> 4 mcg/mL]) or when expected clinical or microbiologic response is delayed
meningococcal meningitis or Haemophilus influenzae type b meningitis.
Mycobacterium avium
Contraindications
Use During Pregnancy and Breastfeeding
does not consider rifampin a contraindication to breastfeeding; a decision to stop breastfeeding or to stop the drug should be made depending on the importance of the drug to the mother.
Adverse Effects
Adverse effects of rifamycins include
Hepatitis (most serious)
Gastrointestinal disturbances
Central nervous system effects
Myelosuppression
Dosing Considerations
Rifaximin
Traveler’s diarrhea, which is caused primarily by enterotoxigenic and enteroaggregative Escherichia coli
E. coliShigella species, Salmonella species, Campylobacter species). The dose for traveler's diarrhea is 200 mg orally every 8 hours for 3 days in adults and children > 12 years.
Portosystemic (hepatic) encephalopathy: The dosage is 550 mg orally 2 times a day.
Irritable bowel syndrome (IBS): The dosage is 550 mg orally 3 times a day.
More Information
The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
Centers for Disease Control and Prevention (CDC): Treatment for TB Disease and Pregnancy
