Review of Fatalities and Adverse Reactions After Administration of -2 Adrenergic Agonist Reversal Agents in the Horse

Elective reversal of -2 adrenergic receptor agonist sedation with either tolazoline or yohimbine is not without serious risk of idiosyncratic and potentially fatal consequences in the horse; as evidenced by clinical reports of drug reaction and possible death resulting from administration of tolazoline or yohimbine to reverse the effects of -2 agonist sedation for veterinary procedures in the horse. Authors’ addresses: Equine Reproduction Laboratory, Colorado State University, Fort Collins, Colorado 80523 (Scofield); Weatherford Equine Medical Center, Weatherford, Texas 76088 (Franklin); and Western College of Veterinary Medicine, Pomona, California 91766 (Alexander and Bertone); e-mail: [email protected]. © 2010 AAEP.