Aemcolo (rifamycin sodium)
Last reviewed · Source: First Databank (FDB) drug data
Overview
Rifamycin sodium is a rifamycin antibiotic.
Rifamycin is an antibacterial drug that belongs to the ansamycin class. Rifamycin inhibits bacterial synthesis and growth through inhibition of the beta-subunit of the bacterial DNA-dependent RNA polymerase, which blocks a step in DNA transcription.
Rifamycin is active in vitro and in clinical infections (i.e., travelers' diarrhea) against most isolates of enterotoxigenic Escherichia coli and enteroaggregative E. coli.
Resistance to rifamycin is associated with mutations in the RNA polymerase beta-subunit. Among E. coli strains, the spontaneous mutation frequency rate of rifamycin ranged from 10-6 to 10-10 at 4-16 times the rifamycin minimum inhibitory concentration (MIC); the mutation frequency was independent of rifamycin concentration. Increases in MICs were observed both in vitro and while on treatment following exposure to rifamycin.
Cross-resistance between rifamycin and other ansamycins has been observed.
Following oral administration, total systemic exposure to rifamycin is minimal based on the recommended human dosage. Under fasting conditions, bioavailability of rifamycin is<0.1% based on total urinary excretion data. In healthy adults receiving the recommended rifamycin dosage (388 mg twice daily for 3 days), maximum plasma concentrations are observed 6 hours after the final dose.
Although a food-effect study indicated that food decreased systemic exposure of rifamycin, this effect is not expected to be clinically relevant. In vitro, metabolism of rifamycin via CYP isoenzymes are not observed. Rifamycin is 80% bound to plasma proteins; binding is primarily to albumin.
After a single 388 mg dose of rifamycin, approximately 86% of the dose is excreted in the feces. The elimination half-life of rifamycin in plasma is unknown.
Generic name: rifamycin sodium
Reference product & biosimilars
No reference, biosimilar or interchangeable associated with this drug.
Today’s intelligence on Aemcolo
Indications
The following indications are listed for Aemcolo:
- Traveler's Diarrhea Due To Noninvasive Strain Of Escherichia Coli
Also known as: Traveler's Diarrhea Due To Noninvasive E. Coli.
Dosing
Dosage of rifamycin sodium is expressed in terms of rifamycin.
Administer orally without regard to food. Do not administer with alcohol. Administer each dose of rifamycin with 6-8 ouncesof liquid.
Swallow rifamycin tablets whole; do not crush, break, or chew.
Store the tablets at 20-25oC (excursions permitted to 15-30oC).
No dosing information is available for this tab.
No dosing information is available for this tab.
Drug interactions
No clinical drug interaction studies have been conducted with rifamycin. Based on the minimal systemic absorption of rifamycin with recommended doses, clinically relevant interactions are not expected.
Rifamycin is not a substrate of cytochrome P-450 (CYP) isoenzymes 1A2, 2B6, 2C9, 2C19, 2D6, 2E1, and 3A4/5. In vitro studies indicate that rifamycin is an inducer of CYP3A4 and 2B6, but not 1A2; however, clinically relevant induction of these enzymes is unlikely. In vitro studies indicate that rifamycin is an inhibitor of CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4/5; clinically relevant inhibition of these enzymes is not likely.
Rifamycin is a substrate of P-glycoprotein (P-gp), and inhibits both P-gp and breast cancer resistance protein (BCRP) in the GI tract. In vitro, studies indicate that rifamycin inhibits renal organic anion transport (OAT) 3, multidrug and toxin extrusion (MATE) 1, and MATE2-K; clinically relevant inhibition of these transporters is not likely.
There are no contraindication interactions for this drug.
There are no severe interactions for this drug.
There are no moderate interactions for this drug.
Contraindications
*Known hypersensitivity to rifamycin, any of the other rifamycin class antimicrobial agents (e.g., rifaximin), or any of the components.
There are no contraindication contraindications for this drug.
There are no severe contraindications for this drug.
There are no moderate contraindications for this drug.
Adverse reactions
Most common adverse reactions (incidence >2%) are headache and constipation.
There are no severe adverse reactions for this drug.
There are no less severe adverse reactions for this drug.
Precautions
No enhanced messaging available.
Safety and efficacy of rifamycin have not been established in pediatric patients <18 years of age.
Data are not available regarding the use of rifamycin in pregnant women. Due to minimal systemic absorption, fetal exposure is not expected with maternal use.
In animal reproductive studies, treatment with rifamycin in rats during organogenesis resulted in maternal toxicity, decreased fetal weight, and teratogenicity at dosages approximately 1000-25,000 times the maximum plasma concentration and systemic exposure (based on AUC), respectively. In rabbits, treatment with rifamycin resulted in maternal toxicity, decreased fetal weight, and slight delays in fetal ossification at dosages approximately 10 times the maximum human plasma concentration.
It is not known whether rifamycin is distributed into human milk, affects human milk production, or affects the breast-fed infant.
Because systemic absorption of rifamycin in humans is negligible following oral administration, the level of exposure to a breastfed infant through breastmilk is expected to be limited.
Benefits of breastfeeding and the importance of rifamycin to the woman should be considered along with the potential adverse effects on the breast-fed child from the drug or from the underlying maternal condition.
The manufacturer makes no specific dosage recommendations for geriatric patients.
Experience in patients 65 yearsof age and older with travelers' diarrhea is insufficient to determine whether they respond differently than younger subjects. Other reported clinical experience has not identified differences in response.
ICD codes
No ICD codes are available for this drug.
Formulary status
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Last reviewed · Source: First Databank (FDB) drug data
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