Intra-articular administration of lidocaine plus adrenaline in dogs: Pharmacokinetic profile and evaluation of toxicity in vivo and in vitro

•Evaluation of the cardio-, neuro- and chondro-toxicity of intra-articular administration of lidocaine plus adrenaline in dogs.•The treatment was not found to cause adverse effects on the cardiovascular system.•The plasma concentrations of lidocaine did not reach neurotoxic concentrations.•Toxic effects of lidocaine on chondrocytes appeared to be reduced by adrenaline.

The aim of this study was to evaluate the safety of intra-articular (IA) lidocaine plus adrenaline for improving peri-operative analgesia in anaesthetized dogs undergoing arthroscopy of the elbow. A solution of lidocaine (L) 1.98% plus adrenaline 1:100.000 was administered via the IA route and its safety evaluated in terms of cardio-, neuro-, and chondro-toxicity.No bradycardia or hypotension was recorded from induction to the last observational time point. Signs of toxicity of the nervous system could have been masked by the general anaesthesia but lidocaine concentrations detected in the blood were lower than those thought to be capable of producing toxicity. The assessment of in vitro chondrotoxicity showed a dose- and time-dependent effect of lidocaine on the viability of articular cells. Adrenaline appeared to reduce the chondrotoxicity of 1% lidocaine, following an exposure of up to 30 min.