Epinepinene atDosesUsedinDentistry Deteriorates Platelet Retention Rate

Epinephrine promotes platelet aggregation through a2receptor-mediated mechanisms. Inthis study, thechange intheplatelet retention rate (PRR) wasinvestigated before andafter submucosal epinephrine injection with orwithout lidocaine inoral surgical patients during isoflurane-nitrous oxide anesthesia. Thirty-nine consenting patients participated inthis study. Subjects wereallocated inoneoffive groups depending onthesolution injected, thediclofenac supplement, andthepatients' age. PRRwasmeasured immediately before and5minafter epinephrine injection using amodified formofSaltzman's method. Injection ofepinephrine with lidocaine deteriorated PRR,although epinephrine without lidocaine produced no PRR change. Epinephrine atdoses used inroutine dental practices mayactivate theplatelet aggregating function. Dentists should keep inmindthat epinephrine elicits both hemodynamic andplatelet-activat ing effects. Thelatter maybeofclinical importance insomesituations.