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 (t_1/2λz), mean volume of distribution at steady state (Vd_ss) 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 t_1/2λz 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.

Keywords: articaine hydrochloride; convulsive dose; disbudding; efficacy; goat kids; pharmacokinetics.