[Ban of the use of metomidate (Hypnodil) in swine. Background, consequences and alternatives].

Since the beginning of 1997 the use of the hypnotic drug metomidate (Hypnodil) in swine is not longer allowed. This ban caused a substantial therapeutic deficit for anesthesia in swine. The ban is based on provisions of the European Council Directive 2377/90 for fixing maximum residue limits (MRL) of veterinary drugs in animal-derived food and due to the fact that the pharmaceutical industry has not submitted any application for determining an MRL for metomidate. According to the regulations of the German drug law only those substances can be used as alternatives which are authorized for use in swine or another food-producing animal species. Registrations for use in swine exist for the barbiturates thiamylal and narcobarbital, for ketamine and for the neuroleptics azaperone, acepromazine and propionylpromazine. In the exceptional case of therapeutic emergency levomethadone or xylazine can be used. The administration of propofol, thiopentone, opioids (except levomethadone) or benzodiazepines (except brotizolam) to swine is not allowed since these drugs are authorized only for use in humans or companion animals. At present the most appropriate alternative for anesthesia in swine is thiamylal after premedication of azaperone and ketamine inducing general anesthesia with sufficient tolerance at low risks. In current studies general anesthesia with tolerance could further be produced by combinations of levomethadone, ketamine and azaperone or xylazine. Combined use of levomethadone with benzodiazepines appeared to be not suitable in swine.