Plasma levels of lidocaine and prilocaine after application of Oraqix, a new intrapocket anesthetic, in patients with advanced periodontitis.

BACKGROUND, AIMS: Oraqix, a new non-injection local anesthetic, lidocaine/prilocaine gel 5%, has been developed to provide pain relief in association with periodontal probing and scaling/root planing (SRP). The aim of this open study was to describe the plasma profiles of lidocaine and prilocaine following a single dose of Oraqix to patients with advanced periodontitis.

METHODS

10 patients with 18 to 28 teeth with pocket depths of at least 4 mm were included. Oraqix was applied in the pockets around all the teeth in the mouth by means of a blunt applicator. The total dose applied per patient was 0.9 to 3.5 g. Directly thereafter all the pockets were probed and 3 teeth subjected to SRP. The mouth was rinsed out with a glass of water 20-27 min after the application of the gel. Blood samples were collected before and up to 90 min after the start of application of Oraqix.

RESULTS

Peak plasma concentrations of lidocaine (99-266 ng/ml) and prilocaine (46-118 ng/ml) occurred 20-40 min after the start of application. These levels were low compared to those reported to cause initial signs of CNS toxicity (5000-6000 ng/ml). Side-effects were few and mild local effects of short duration.

DISCUSSION: In conclusion, there is a large safety margin with respect to systemic effects following the application of up to 3.5 g Oraqix in periodontal pockets.