Rifaximin

INTRODUCTION

Indications

Travelers' diarrhea due to noninvasive strains of Escherichia coli.

Action

Inhibits bacterial RNA synthesis by binding to bacterial DNA-dependent RNA polymerase. Therapeutic Effects: Decreased severity of travelers' diarrhea. Spectrum: E. coli (enterotoxigenic and enteroaggregative strains).

Adverse Reactions/Side Effects

CNS: dizziness. GI: PSEUDOMEMBRANOUS COLITIS.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Monitor signs of pseudomembranous colitis, including diarrhea, abdominal pain, fever, pus or mucus in stools, and other severe or prolonged GI problems (nausea, vomiting, heartburn). Notify physician or nursing staff immediately of these signs.

• Assess dizziness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician and nursing staff, and caution the patient and family/caregivers to guard against falls and trauma.

Interventions

• Always wash hands thoroughly and disinfect equipment (whirlpools, electrotherapeutic devices, treatment tables, and so forth) to help prevent the spread of infection. Use universal precautions or isolation procedures as indicated for specific patients.

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.

Contraindications/Precautions

Contraindicated in: Hypersensitivity to rifaximin or other rifamycins; Diarrhea with fever or bloody stools; Diarrhea caused by other infections agents; Lactation.

Use Cautiously in: Pregnancy (use only benefits outweigh risk to fetus); Children <12 yr (safety not established).

Interactions

Drug-Drug: Although rifaximin induces the CYP3A4 enzyme system, since it is not absorbed, drug interactions are unlikely.

Route/Dosage

PO (Adults and Children ≥12 yr): 200 mg tid for 3 days.

Availability

Tablets: 200 mg.