An extended release local anaesthetic: potential for future use in veterinary surgical patients?

One of the most effective means of preventing the transduction and transmission of acute and perioperative pain is through the use of local anaesthetics. However, local anaesthetics currently available have a relatively short duration of action. Although there are several tools available to treat perioperative pain in companion animals, overall, there is an unmet need for products that can be administered in the clinic, and provide pain relief for the crucial first few days following surgery in the home environment. Specifically, in relation to local anaesthetics, there is a clear unmet need for a long‐acting local anaesthetic that can be added to the multimodal analgesic protocol to provide pain relief to patients in the home environment or during extended hospitalization. Bupivacaine liposomal injectable suspension recently became available for use in humans, and has proven efficacious and safe. This paper will review the use of local anaesthetics, particularly bupivacaine, in dogs and cats, and introduce a new formulation of prolonged release bupivacaine that is in development for dogs and cats. Local anaesthetics are recommended as part of the multimodal approach to the control of preoperative pain. Indeed, they are arguably the only drug class that can completely prevent or stop postoperative pain. However, currently available local anaesthetics have a limited duration of action which is insufficient to bridge the time period from surgery to the home environment. This unmet need for longer acting local anaesthetics is being addressed with the development of slow‐release bupivacaine preparations providing 72 h of pain relief.