Pharmacokinetics, efficacy and convulsive dose of articaine hydrochloride in goat kids.

ABSTRACT

OBJECTIVE: To investigate the pharmacokinetics, efficacy and convulsive dose of articaine hydrochloride in goat kids. STUDY DESIGN: Experimental prospective study. ANIMALS A total of 18 (n = 6 animals per experiment) male Saanen goat kids (2-4 weeks old). METHODS: The study consisted of three experiments. The first determined the pharmacokinetics of articaine following intravenous administration of articaine hydrochloride (8 mg kg-1). The second experiment investigated the anaesthetic efficacy and pharmacokinetics following cornual nerve block using 1.5% articaine hydrochloride. Anaesthesia of horn buds was evaluated using the response to pinprick test. Non-compartmental analysis was used. The final experiment determined the convulsive dose of articaine and its corresponding plasma concentration following intravenous infusion of articaine hydrochloride (4 mg kg-1 minute-1). Data are shown as mean ± standard deviation. RESULTS: The mean terminal half-life (t1/2λz), mean volume of distribution at steady state (Vdss) and mean plasma clearance (CL) of articaine following intravenous administration were 0.66 hour, 3.81 L kg-1 and 5.33 L hour-1 kg-1, respectively. After cornual nerve block, the mean maximum plasma concentration of articaine was 587 ng mL-1 at 0.22 hour and its mean t1/2λz was 1.26 hours. Anaesthesia of horn buds was observed within 4 minutes following cornual nerve block. The mean dose required to produce convulsions was 16.24 mg kg-1 and mean convulsive plasma concentrations of articaine and articainic acid were 9905 and 1517 ng mL-1, respectively. CONCLUSIONS: Intravenous administration of 8 mg kg-1 of articaine hydrochloride did not cause any adverse effects. Pharmacokinetic data suggest that articaine was rapidly eliminated and cleared. Cornual nerve block using 1.5% articaine hydrochloride alleviated the response to the acute nociceptive stimulus during disbudding. CLINICAL RELEVANCE Articaine hydrochloride appears to be a safe and effective local anaesthetic for disbudding in goat kids.