TITLE: PROPHYLACTIC EMETOGENIC RECEPTOR ANTAGONISM: IS MORE BETTER?

AUTHORS: David N. Thrush, MD, John Locket, MD, Nader Said, MD
AFFILIATION: University of South Florida, Tampa, FL.

Anti-emetics may antagonize more than one receptor, e.g., dopaminergic, histaminic, muscarinic, and serotonergic. We compared two anti-emetic regimens with varied receptor antagonism in ambulatory surgery patients. After IRB approval, thirty-one patients randomly were assigned to receive either MEDDS (metaclopramide 10mg, ephedrine 5mg, droperidol 0.625mg, diphenhydramine 12.5mg and scopolamine 0.05mg), or MD (metaclopramide 10mg and droperidol 0.625mg) preoperatively. The incidences of nausea and vomiting in the PACU and during the first 24h after PACU discharge were recorded. Aldrete sedation score was recorded at PACU admission and 30min later. Intergroup data were compared with Student's t (interval data), chi-square (incidence data) or Mann- Whitney tests (score data). There were no intergroup differences in age (45"13 years, pooled), weight (84"20kg, pooled), anesthesia time (39"32min, pooled), gender distribution, opera- tive procedures, use of pharmaceuticals, incidence of nausea and vomiting, or sedation scores. Pooled incidence of PONV was 7% (PACU) and 20% (24h post-PACU). One patient in each group was nauseated, but no patient vomited, in the PACU. Within 24h after PACU discharge, of the patients who received MEDDS, two were nauseated, and of the patients who received MD, three patients were nauseated and one vomited. We conclude prophylactic antagonism of more emetic receptors with MEDDS was no more effective preventing PONV than MD.