PHARMACOKINETICS AND EFFECTS OF XYLAZINE (ROMPUN(R)) IN DOGS

Six beagle dogs were treated with xylazine hydrochloride (1 mg/kg i.m. ). The plasma xylazine concentration was measured by HPLC. Additionall y, clinical effects were registered (cardiac rate, respiratory activit y, electrocardiogram, body temperature, motoric activity, attention, a nalgesia). Maximum plasma concentrations were measured after 15 minute s (476 ng/ml). The plasma half-life was 24 minutes. Sedation was regis tered over one hour (xylazine concentration of more than 150 ng/ml). W ithin the first 30 minutes after treatment (xylazine concentration of more than 300 ng/ml), a low-grade analgesia was observed. In contrast, cardiac and respiratoric depression and also significantly diminished body temperature were registered over 2 to 3 hours.