Aemcolo (rifamycin sodium)

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 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.

Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

Antibiotics/Fecal Microbiota

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: Fecal microbiota is a suspension of live bacteria, which may be compromised by concurrent use of antibiotics.(1)

CLINICAL EFFECTS: Antibiotics may decrease the effectiveness of fecal microbiota.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Antibiotics should not be used concurrently with fecal microbiota. Antibacterial treatment should be completed for 24 to 72 hours before initiating treatment with fecal microbiota. Do not use antibiotics for up to 8 weeks after fecal microbiota.(1)

DISCUSSION: Antibiotics may compromise the effectiveness of fecal microbiota.

Antibiotics/Fecal Microbiota Spores

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: Fecal microbiota spores is a suspension of live bacterial spores, which may be compromised by concurrent use of antibiotics.(1)

CLINICAL EFFECTS: Antibiotics may decrease the effectiveness of fecal microbiota spores.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Antibiotics should not be used concurrently with fecal microbiota spores. Antibacterial treatment should be completed for 2 to 4 days before initiating treatment with fecal microbiota spores.(1)

DISCUSSION: Antibiotics may compromise the effectiveness of fecal microbiota spores.

Antimicrobials/Live Typhoid Vaccine

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: The antimicrobial may be active against the organism in the live-vaccine. Antimicrobial therapy may prevent the vaccine organism from replicating enough to trigger an immune response.(1)

CLINICAL EFFECTS: Vaccination may be ineffective.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Do not give oral typhoid vaccine until 72 hours after the last dose of antimicrobial. If possible, to optimize vaccine effectiveness, do not start antibacterial drugs for 72 hours after the last dose of oral typhoid vaccine. A longer interval should be considered for long-acting antimicrobials, such as azithromycin.(3)

DISCUSSION: Because antimicrobial therapy may prevent sufficient vaccine-organism replication to generate an immune response, the manufacturer of live-attenuated typhoid vaccine and the Centers for Disease Control (CDC) state that the vaccine should not be administered to patients receiving antimicrobial therapy.(1-3)

There are no severe interactions for this drug.

There are no moderate interactions for this drug.

*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.

• Clostridioides difficile infection

There are no moderate contraindications for this drug.

Most common adverse reactions (incidence >2%) are headache and constipation.

Rare or Very Rare

• Clostridioides difficile infection

More Frequent

• Constipation
• Headache disorder

Less Frequent

• Acute abdominal pain
• Dyspepsia
• Fever

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.