rifaximin: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
rifaximin: clinical details
Prescribing considerations
- Licensed for secondary prevention of overt hepatic encephalopathy in adults, not as an acute rescue treatment.
- Review precipitating causes if cognition worsens despite treatment.
- Exercise caution in severe hepatic impairment, particularly with advanced disease scores.
- Renal impairment has not been clinically studied; use caution.
- Consider antimicrobial stewardship and avoid unnecessary concurrent antibacterials.
Contraindications and cautions
- Hypersensitivity to rifaximin, another rifamycin derivative or an excipient
- Intestinal obstruction
- Do not restart after rifaximin-associated Stevens–Johnson syndrome or toxic epidermal necrolysis
Monitoring
- Monitor clinical recurrence, cognition, adherence and adverse effects.
- Assess promptly for severe diarrhoea or suspected Clostridioides difficile infection.
- Monitor closely for serious skin reactions, especially early after initiation.
- Monitor INR when rifaximin is added to or withdrawn from warfarin therapy.
- Use closer clinical observation in severe hepatic impairment.
Clinical pharmacology
Rifaximin irreversibly inhibits bacterial DNA-dependent RNA polymerase. Gastrointestinal absorption is normally below one percent, and most administered material is excreted in faeces; systemic exposure rises with worsening hepatic impairment. Its low absorption limits usefulness against invasive infections.
Formulation and product differences
- The selected product is a pink, oval, film-coated tablet marked “RX”.
- It is essentially sodium-free and requires no special storage conditions.
rifaximin preparations and strengths
Tablet
Route: Oral
Strengths: 200 mg, 550 mg
rifaximin interactions
Tell the prescriber or pharmacist about all medicines, including these important examples:
Warfarin and other oral anticoagulants
Rifaximin has been associated with increases or decreases in INR; closer monitoring may be required when it is started or stopped.
Ciclosporin
Ciclosporin can markedly increase systemic exposure to rifaximin, so concurrent use requires caution.
Other rifamycin antibiotics
Concurrent use is not recommended because evidence is lacking and substantial disruption of gut flora is possible.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.