Xifaxan


rifiximin

Xifaxan

Pharmacologic class: Rifampin-related antibiotic

Therapeutic class: Anti-infective

Pregnancy risk category C

Action

Binds to beta-subunit of bacterial DNA-dependent RNA polymerase, inhibiting bacterial RNA synthesis

Availability

Tablets: 200 mg, 550 mg

Indications and dosages

➣ Travelers' diarrhea caused by noninvasive strains of Escherichia coli

Adults and children age 12 and older: 200 mg P.O. three times daily for 3 days

➣ Reduction of risk of overt hepatic encephalopathy recurrence

Adults: 550 mg P.O. b.i.d.

Off-label uses

• Hepatic encephalopathy

Contraindications

• Hypersensitivity to drug, its components, or rifamycin anti-infectives

Precautions

Use cautiously in:

• elderly patients

• pregnant or breastfeeding patients

• children (safety and efficacy not established in those younger than age 12).

Administration

• Administer with or without food.

• Don't give to patients with diarrhea complicated by fever or blood in stool or to patients with suspected Campylobacter jejuni, Shigella, or Salmonella infection.

Adverse reactions

CNS: headache

GI: nausea, vomiting, constipation, flatulence, abdominal pain, rectal tenesmus, defecation urgency, pseudomembranous colitis

Other: pyrexia, overgrowth of susceptible organisms

Interactions

None

Patient monitoring

• Monitor for fever, blood in stools, and worsening of diarrhea.

• Monitor patient's fluid and electrolyte status.

• Monitor for new infections; if needed, consider alternative therapy.

Patient teaching

• Tell patient drug can be taken with or without food.

See Advise patient to stop drug and notify prescriber if diarrhea symptoms worsen or last beyond 48 hours.

• As appropriate, review all other significant or life-threatening adverse reactions.

rifaximin

(ri-fax-i-min) rifaximin,

Xifaxan

(trade name)

Classification

Therapeutic: anti infectives
Pharmacologic: rifamycins
Pregnancy Category: C

Indications

Travelers' diarrhea due to noninvasive strains of Escherichia coli.Reduction in risk of overt hepatic encephalopathy recurrence.

Action

Inhibits bacterial RNA synthesis by binding to bacterial DNA-dependent RNA polymerase.

Therapeutic effects

Decreased severity of travelers' diarrhea.Decreased episodes of overt hepatic encephalopathy.Escherichia coli (enterotoxigenic and enteroaggregative strains).

Pharmacokinetics

Absorption: Poorly absorbed (<0.4%), action is primarily in GI tract.Distribution: 80–90% concentrated in gut.Metabolism and Excretion: Almost exclusively excreted unchanged in feces.Half-life: 6 hr.

Time/action profile

ROUTEONSETPEAKDURATION
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Contraindications/Precautions

Contraindicated in: Hypersensitivity to rifaximin or other rifamycins;Diarrhea with fever or bloody stools;Diarrhea caused by other infections agents; Lactation: Potential for adverse effects in the infant. Switch to formula for duration of treatment.Use Cautiously in: Obstetric: Use only if benefit to mother outweighs risk to fetus; Pediatric: Safety not established in children <18 yr (hepatic encephalopathy) or <12 yr (travelers' diarrhea).

Adverse Reactions/Side Effects

Central nervous system

  • dizziness (most frequent)

Cardiovascular

  • peripheral edema (most frequent)

Gastrointestinal

  • pseudomembranous colitis (life-threatening)

Interactions

Drug-Drug interaction

Although rifaximin induces the CYP 3A4 enzyme system, since it is not absorbed, drug interactions are unlikely.

Route/Dosage

Travelers' Diarrhea

Oral (Adults and Children ≥12 yr) 200 mg 3 times daily for 3 days.

Hepatic Encephalopathy

Oral (Adults) 550 mg twice daily.

Availability

Tablets: 200 mg, 550 mg

Nursing implications

Nursing assessment

  • Traveler's Diarrhea: Assess frequency and consistency of stools and bowel sounds prior to and during therapy.
  • Assess fluid and electrolyte balance and skin turgor for dehydration.
  • Hepatic Encephalopathy: Assess mental status periodically during therapy.
  • Monitor bowel function. Diarrhea, abdominal cramping, fever, and bloody stools should be reported to health care professional promptly as a sign of pseudomembranous colitis. May begin up to several weeks following cessation of therapy.
  • Lab Test Considerations: May cause lymphocytosis, monocytosis, and neutropenia.

Potential Nursing Diagnoses

Diarrhea (Indications)
Risk for deficient fluid volume (Indications)

Implementation

  • Do not confuse rifaximin with rifampin.
  • Oral: Administer with or without food.

Patient/Family Teaching

  • Instruct patient to take rifaximin as directed and to complete therapy, even if feeling better. Caution patient to stop taking rifaximin if diarrhea symptoms get worse, persist more than 24–48 hr, or are accompanied by fever or blood in the stool. Consult health care professional if these occur. Advise patient not to treat diarrhea without consulting health care professional. May occur up to several weeks after discontinuation of medication.
  • May cause dizziness. Caution patient to avoid driving and other activities requiring alertness until response to medication is known.
  • Advise female patients to notify health care professional if pregnant or if pregnancy is suspected, or if breast feeding.

Evaluation/Desired Outcomes

  • Decreased severity of travelers' diarrhea.
  • Reduction in risk of overt hepatic encephalopathy recurrence.