Names and pronunciation
(rif-ax′i-min) Xifaxan, Zaxine
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Drug reference
(rif-ax′i-min) Xifaxan, Zaxine
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Func. class.: Antiinfective—miscel- laneous
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Chem. class.: Analog of rifAMPin
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Do not confuse: rifAXIMin/rifAMPin
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ACTION: Binds to bacterial-DNA– dependent RNA polymerase, thereby inhibiting bacterial RNA synthesis
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USES: Traveler’s diarrhea in those ≥12 yr caused by E. coli, hepatic encepha lopathy, irritable bowel syndrome Unlabeled uses: Crohn’s disease, CDAD, traveler’s diarrhea prophylaxis
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CONTRAINDICATIONS: Hyper sensitivity to product, rifamycins; diar rhea with fever, systemic infections Precautions: Pregnancy, breastfeeding, children, geriatric patients, CDAD
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SIDE EFFECTS CNS: Abnormal dreams, dizziness, insomnia, headache, fatigue, depression CV: Hypotension, chest pain, peripheral edema, ascites GI: Abdominal pain, constipation, defecation urgency, flatulence, nau- sea, rectal tenesmus, vomiting, ascites, CDAD GU: Proteinuria, polyuria, increased uri- nary frequency MISC: Pyrexia, motion sickness, tinnitus, rash, photosensitivity, exfoliative dermatitis MS: Arthralgia, muscle pain, myalgia RESP: Dyspnea, cough, pharyngitis
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INTERACTIONS Increase: effect of—afatinib Increase: levels—P-glycoprotein inhibitors Drug/Lab Test Increase: LFTs, potassium Decrease: blood glucose, sodium
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DOSAGE AND ROUTES Hepatic encephalopathy • Adult: PO 550 mg bid Traveler’s diarrhea • Adult/child ≥12 yr: PO 200 mg tid × 3 days without regard to meals Irritable bowel syndrome • Adult: PO 550 mg tid × 14 days, may give another 2 courses if recurrence Crohn’s disease (unlabeled) • Adult: PO 200 mg tid × 16 wk CDAD (unlabeled) • Adult: PO 400 mg tid × 20 days after 10 days of vancomycin PO for second/ R third recurrence
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Available forms: Tabs 200, 550 mg
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Administer: • Without regard to food
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Assess: • Hepatic encephalopathy: lethargy, con- fusion, coma, difficulty thinking, person- ality changes, poor concentration, sweet breath odor, inverted sleep/wake cycles • GI symptoms: amount, character of diarrhea; abdominal pain, nausea, vomit- ing, blood in stool; do not use in those with blood in stool, increased tempera- ture with diarrhea • Overgrowth of infection, CDAD • Pregnancy/breastfeeding: do not use in 1st trimester; use only if benefits out- weigh fetal risk; do not breastfeed, excre- tion unknown
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Evaluate: • Therapeutic response: absence of in- fection
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CLINICAL CONSIDERATIONS
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Patient and caregiver information: • To discontinue rifAXIMin, notify pre- scriber if diarrhea persists >24-48 hr, if diarrhea worsens, or if blood in stools and fever present • To avoid hazardous activities if dizzi- ness occurs • To notify prescriber if pregnancy is planned, suspected • That headache, rash, insomnia, abnor- mal dreams, tinnitus may occur • To take without regard to food • To take as directed, consume all of the product prescribed
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PHARMACOKINETICS Low systemic absorption, distribution to GI tract, half-life 1.8-4.5 hr, excreted in feces, peak 1-4 hr
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• Adult/child ≥12 yr: PO 200 mg tid × 3 days without regard to meals Irritable bowel syndrome
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