Ondansetron: a review of pharmacokinetics and clinical experience in postoperative nausea and vomiting

Introduction: Postoperative nausea and vomiting (PONV) is associated with poor patient satisfaction and delayed recovery after general anesthesia. Multiple neurotransmitters are involved in the mediation of PONV but despite the introduction of new antiemetics, no completely effective drug exists for its prevention or treatment. Areas covered: This review provides a detailed description of ondansetron's chemistry, pharmacokinetics, pharmacodynamics, toxicity and a brief review of clinical trials involving ondansetron and the management of PONV. We searched reviews, meta-analysis and randomized controlled trials (Medline, Embase and article reference lists). Expert opinion: According to current literature, administering ondansetron 4 mg i.v. near the end of surgery provides sufficient protection against PONV in low- and moderate-risk patients, comparable to traditional antiemetics such as antihistamines and droperidol. High-risk patients require a multimodal approach since one quarter of them will not respond to monotherapy. In the future, transdermal formulation or formulations for nasal or buccal delivery will be available. The development of non-racemic mixture consisting of R-ondansetron would enhance the safety profile and probably the efficacy too.