Gabapentin is often used in dogs and cats to prevent seizures and treat neuropathic pain.
MECHANISM OF ACTION
Although gabapentin is a structural analog of the neurotransmitter gamma-aminobutyric acid (GABA), it appears not to interact with GABA receptors.
- Its mechanism of action is not entirely clear but is likely related to inhibition of calcium and, possibly, sodium channels.1
- Gabapentin is excreted unchanged in humans but is metabolized to N-methyl-gabapentin in dogs.
- Results in faster elimination and ability for shorter dose intervals in dogs as compared with humans2
- The metabolism of gabapentin has not been studied in cats, but pharmacokinetics demonstrates faster elimination than in humans, with similar implications for dose intervals as in dogs.3
Gabapentin has been used as an adjunct treatment for seizures in dogs and cats and as treatment for neuropathic pain.4-9
- Gabapentin may be effective as an adjunct treatment for acute pain in humans (eg, pain following some surgeries, including spinal surgery and hysterectomy) and, to a lesser extent, in dogs and cats.10-16
- However, meta-analyses of human studies have failed to show strong benefits.17,18
- A single case report described the successful use of gabapentin in the management of neuropathic pain in a horse.19
- Most evidence showing efficacy of gabapentin in pain management in animals is anecdotal and not based on controlled studies.
The recommended dose is variable, ranging from 10-20 mg/kg q8-12h in dogs4,7-9,20 and 3-20 mg/kg q6-24h in cats.7,14-16,20
- A dose of 2.5 mg/kg q12h has been used in a horse to treat neuropathic pain.19
Gabapentin has anecdotally been used in cats as a sedative to facilitate veterinary visits and procedures (eg, physical examination).
- Doses of 50 mg/cat and 100 mg/cat have been shown to attenuate fear response in cats treated as part of a trap-neuter-return program.21
Sedation and ataxia are the most common adverse effects.8,9,20
- Usually observed when doses at the higher end of the dose range are administered or when combined with other drugs that cause sedation
- May decrease after a few days of administration9,20
Some liquid formulations of gabapentin contain xylitol, which is toxic in dogs; other formulations are xylitol free.
- The xylitol-containing formulation may result in hypoglycemia in dogs when administered at the higher end of the dose range.
- However, more severe toxicity (ie, liver failure) is unlikely unless extremely high doses (ie, >80 mg/kg) are used.20
- Kukkar A, Bali A, Singh N, Jaggi AS. Implications and mechanism of action of gabapentin in neuropathic pain. Arch Pharm Res. 2013;36(3):237-251.
- Radulovic LL, Türck D, von Hodenberg A, et al. Disposition of gabapentin (neurontin) in mice, rats, dogs, and monkeys. Drug Metab Dispos. 1995;23(4):441-448.
- Siao KT, Pypendop BH, Ilkiw JE. Pharmacokinetics of gabapentin in cats. Am J Vet Res. 2010;71(7):817-821.
- Moore SA. Managing neuropathic pain in dogs. Front Vet Sci. 2016;3:12.
- Plessas IN, Volk HA, Rusbridge C, Vanhaesebrouck AE, Jeffery ND. Comparison of gabapentin versus topiramate on clinically affected dogs with Chiari-like malformation and syringomyelia. Vet Rec. 2015;177(11):288.
- Inkpen H. Chronic progressive polyarthritis in a domestic shorthair cat. Can Vet J. 2015;56(6):621-623.
- Muñana KR. Management of refractory epilepsy. Top Companion Anim Med. 2013;28(2):67-71.
- Govendir M, Perkins M, Malik R. Improving seizure control in dogs with refractory epilepsy using gabapentin as an adjunctive agent. Aust Vet J. 2005;83(10):602-608.
- Platt SR, Adams V, Garosi LS, et al. Treatment with gabapentin of 11 dogs with refractory idiopathic epilepsy. Vet Rec. 2006;159(26):881-884.
- Aghighi SA, Tipold A, Piechotta M, Lewczuk P, Kästner SB. Assessment of the effects of adjunctive gabapentin on postoperative pain after intervertebral disc surgery in dogs. Vet Anaesth Analg. 2012;39(6):636-646.
- Wagner AE, Mich PM, Uhrig SR, Hellyer PW. Clinical evaluation of perioperative administration of gabapentin as an adjunct for postoperative analgesia in dogs undergoing amputation of a forelimb. J Am Vet Med Assoc. 2010;236(7):751-756.
- Chang CY, Challa CK, Shah J, Eloy JD. Gabapentin in acute postoperative pain management. Biomed Res Int. 2014. doi: 10.1155/2014/631756
- Backonja M, Glanzman RL. Gabapentin dosing for neuropathic pain: evidence from randomized, placebo-controlled clinical trials. Clin Ther. 2003;25(1):81-104.
- Vettorato E, Corletto F. Gabapentin as part of multi-modal analgesia in two cats suffering multiple injuries. Vet Anaesth Analg. 2011;38(5):518-520.
- Lorenz ND, Comerford EJ, Iff I. Long-term use of gabapentin for musculoskeletal disease and trauma in three cats. J Feline Med Surg. 2013;15(6):507-512.
- Steagall PV, Monteiro-Steagall BP. Multimodal analgesia for perioperative pain in three cats. J Feline Med Surg. 2013;15(8):737-743.
- Fabritius ML, Geisler A, Petersen PL, et al. Gabapentin for post-operative pain management – a systematic review with meta-analyses and trial sequential analyses. Acta Anaesthesiol Scand. 2016;60(9):1188-1208.
- Doleman B, Heinink TP, Read DJ, Faleiro RJ, Lund JN, Williams JP. A systematic review and meta-regression analysis of prophylactic gabapentin for postoperative pain. Anaesthesia. 2015;70(10):1186-1204.
- Davis JL, Posner LP, Elce Y. Gabapentin for the treatment of neuropathic pain in a pregnant horse. J Am Vet Med Assoc. 2007;231(5):755-758.
- KuKanich B. Outpatient oral analgesics in dogs and cats beyond nonsteroidal antiinflammatory drugs: an evidence-based approach. Vet Clin North Am Small Anim Pract. 2013;43(5):1109-1125.
- Pankratz KE, Ferris KK, Griffith EH, Sherman BL. Use of single-dose oral gabapentin to attenuate fear responses in cage-trap confined community cats: a double-blind, placebo-controlled field trial. J Feline Med Surg. 2017. doi: 10.1177/1098612X17719399
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