VN June 2021

Vetnuus | Junie 2021 14 Drug & Class Dose, Frequency, & Route Advantages Disadvantages Notes Gabapentin 3-20 mg/kg PO every 8-12 hours Minimal adverse effects One study has indicated efficacy for treatment of OA-associated pain in cats 18 Oral twice- to three-times-daily administration Can cause sedation Often a controlled drug Proven effective for calming prior to transport to the clinic, which may decrease pain, as pain causes anxiety and anxiety exacerbates pain Amantadine (NMDA- receptor antagonist) 3-5 mg/kg PO every 12 hours Minimal adverse effects Potential for significant pain relief due to monoamine oxidase inhibition Oral twice-daily administration Efficacy can be difficult to determine Dosing is based on one canine study and may be inadequate Neither pharmacokinetics nor pharmacodynamics have been studied in cats Ketamine (NMDA- receptor antagonist) 4-10 µg/kg/min IV following a loading dose of 0.5 mg/kg Minimal adverse effects Potential for significant pain relief due to monoamine oxidase inhibition Patient must be hospitalised for infusion Repeat infusions may be necessary Proven effective in other species, particularly in patients with pain of central sensitisation Most effective dose and infusion duration are unknown and are likely highly individual Amitriptyline (tricyclic anti­ depressant) 3-4 mg/kg PO every 12 hours Minimal adverse effects Oral twice-daily administration Cats typically do not like the taste Serotonin-reuptake inhibition may provide analgesia through the descending inhibitory limb of the pain pathway Tramadol (opioid) 1-2 mg/kg PO every 12 hours Two studies indicate efficacy for treatment of OA-associated pain in cats 19,20 Cats typically do not like the taste Oral twice- to three-times-daily administration Can cause sedation or dysphoria Controlled drug Adverse effects like dysphoria, sedation, and diarrhoea are common at the effective dose 19 Buprenor­ phine (opioid) 0.02-0.05 mg/kg oral transmucosal every 8-12 hours Opioid-level pain relief Potential adverse effects Oral twice- to three-times-daily administration Controlled drug Opioids are not ideal for treatment of chronic pain Oral transmucosal absorption is fairly low, potentially leading to the need for higher doses v Content from Around the Globe, FREE. Subscribe to Global Brief , the weekly global Clinician’s Brief newsletter. It's FREE for all members of WSAVA associations. GLOBAL CONTENT DELIVERED DIRECTLY TO YOU SUBSCRIBE TODAY AT CLINICIANSBRIEF.COM/GLOBAL