The Committee recommended the addition of a square box to the listing of ondansetron on the EML and EMLc, noting that the original recommendation to list ondansetron in 2009 had included a square box.
Ondansetron was first included on the EML and EMLc following a review of antiemetic medicines considered by the 2009 Expert Committee (1). Listing was recommended with a square box symbol, designating ondansetron as representative of the pharmacological class of 5-HT3 receptor antagonists. However, the square box was inadvertently omitted when the lists were published.
Alternative 5-HT3 receptor antagonists within the pharmacological class are shown below:
A 2016 systematic review of 299 studies (58 412 patients) identified during the application review process investigated the comparative safety and effectiveness of 5-HT3 receptor antagonists in patients undergoing chemotherapy. The review concluded that most 5-HT3 receptor antagonists used alone, or in combination with corticosteroids, were effective at decreasing the occurrence of nausea and/or vomiting, and were similarly safe when compared to each other (2).
Cost / cost effectiveness
The square box indicating therapeutic equivalence between alternative 5-HT3 receptor antagonists will allow tendering among available options or competition in pooled procurement mechanisms at country/local level or benchmarking for lowering prices.
The 5-HT3 receptor antagonists have wide market availability and are available in generic forms.
Comments on the application were received from the WHO Department of Management of NCDs, Disability, Violence and Injury Prevention. The technical unit advised that it supported the addition of a square box to the listings of
ondansetron as representative of the pharmacological class of 5-HT3 receptor antagonists, stating that this class of medicines are essential medicines for the optimal management of common treatment-related adverse events associated with emetogenic chemotherapy.
1. The selection and use of essential medicines. Report of the WHO Expert Committee, 2009 (including the 16th WHO Model List of Essential Medicines and the 2nd WHO Model List of Essential Medicines for Children) (WHO Technical Report Series, No. 958). Geneva: World Health Organization; 2009. Available from https://apps.who.int/iris/bitstream/handle/10665/44287/WHO_TRS_958_eng.pdf, accessed 30 October 2019.
2. Tricco AC, Blondal E, Veroniki AA, Soobiah C, Vafaei A, Ivory J et al. Comparative safety and effectiveness of serotonin receptor antagonists in patients undergoing chemotherapy: a systematic review and network meta-analysis. BMC Med. 2016;14(1):216.