UMEM Educational Pearls

Category: Pharmacology & Therapeutics


Keywords: ondansetron, zofran, prolonged QT, torsades, drug interactions, ciprofloxacin, antifungal, azoles (PubMed Search)

Posted: 2/2/2012 by Ellen Lemkin, MD, PharmD
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There are many profound interactions with ondansetron that can potentially prolong the QT, leading to Torsades in susceptible patients
The highlights include:
  • Antifungal agents (the -azoles)
  • Class III antiarrhythmics
  • Fluoroquinolones
  • Low potency antipsychotic
It is actually CONTRAINDICATED in patients on ciprofloxacin
Use CAUTION in patients with electrolyte abnormalities, bradycardia, and CHF.
There are several other medication contraindications, including apomorphine, thioridazine, posaconazole, pimozide, sparfloxacin and cisapride.