Clinical pharmacology and the use of articaine for local and regional anaesthesia

Quicker onset and shorter elimination time favours (+/-) articaine as a short-acting local anaesthetic for regional anaesthesia in day-case settings, e.g. arthroscopy (shoulder, knee), hand and foot surgery, and dentistry, because patients treated with articaine will be 'drug free' more quickly than those who receive other local anaesthetics. Articaine diffuses better through soft tissue and bone than other local anaesthetics. The concentration of articaine in the alveolus of a tooth in the upper jaw after extraction was about 100 times higher than that in systemic circulation. Articaine is metabolised via hydrolysis into articainic acid, 75% of which in turn is excreted as such and 25% in the glucuronidated form by the kidneys. The half-lives of elimination (t1/2alpha and t1/2beta) of articaine are 0.6 and 2.5 hours, whereas the apparent half-life of the metabolite articainic acid is 2.5 hours. Intrinsic half-lives of articainic acid are: t1/2alpha 12 minutes, and t1/2beta 64 minutes (1 hour). In dentistry, articaine is the drug of choice in the vast majority of literature. In other regional anaesthesia techniques (intravenous regional anaesthesia, epidural, spinal and plexus blocks) there are not enough data to prove that (+/-) articaine is safer and more effective than the short-acting local anaesthetics lidocaine, (+/-) prilocaine or (+/-) mepivacaine.