Pharmacodynamic Properties

Articaine is a local anaesthetic of the amide type. Preclinical pharmacodynamic studies show that the mechanism of action of articaine is similar to that of other commonly used anaesthetics (lidocaine, procaine, prilocaine). Inhibition of the generation and the conduction of the action potential but no change in resting potential is shown.

Articaine blocks sodium channels and, with lower sensitivity, potassium channels at neutral pH. Inhibition of muscle activation after nerve stimulation and depression of cardiac electrophysiologic measurements demonstrate that articaine has the same pharmacologic activities as other local anaesthetics. When injected close to sensitive nerve filaments, articaine has the reversible effect of blocking the conduction of painful sensations.

Pharmacokinetic Properties

Distribution

Approximately 60 to 80% of articaine hydrochloride is bound to human serum albumin and γ-globulins at 37°C in vitro.

Metabolism

Articaine is rapidly metabolized by plasma carboxyesterase to its primary metabolite, articainic acid which is inactive. Articainic acid concentration reaches its peak about 30 to 60 minutes following the peak in articaine concentration. In vitro studies show that the human liver microsome P450 isoenzyme system metabolises approximately 5% to 10% of the available articaine with nearly quantitative conversion to articainic acid.

Excretion

The elimination half-life of articaine is about 1.8 hours and that of articainic acid is about 1.5 hours. Articaine is excreted primarily through urine with 53-57% of the administered dose eliminated in the first 24 hours following submucosal administration. Articainic acid is the primary metabolite in urine. A minor metabolite, articainic acid glucuronide, is also excreted in urine. Articaine constitutes only 2% of the total dose in excreted urine.

Special Populations

Effect of Age: No pharmacokinetic data is available in the following populations: elderly, children.

Race: No pharmacokinetic data is available for different racial groups.

Renal and Hepatic Insufficiency: No pharmacokinetic data is available for patients with hepatic or renal impairment.