Felis ISSN 2398-2950

Analgesia: NSAID

Contributor(s): John Dodam, David Godfrey, Jo Murrell

Introduction

Non steroidal anti-inflammatory drugs (NSAIDs)

  • Traditional NSAIDs produce analgesia by their anti-cyclooxygenase action.
  • Reduction of inflammation also helps to reduce the pain associated with inflammation.
  • Can be used for treatment of acute or chronic pain.
  • Many of these drugs also have an antipyretic effect and some are licensed just for this property in cats.
  • Toxic effects of NSAIDs are caused partly by inhibition of the production of prostaglandins that protect homeostasis of the kidneys and gastrointestinal tract.
  • The cat is particularly susceptible to the toxic effects of some NSAIDs due to its deficiency of the hepatic glutathione-dependent enzyme system which is involved in metabolism of many of the NSAIDs. This leads to build-up of toxic levels of active compounds when cats are given doses and frequences safe in other species.
  • Toxicity may be exacerbated by using more than one NSAID concurrently or within 24 hours of dosing with a different NSAID or corticosteroid, or administering to a dehydrated, hypovolemic or hypotensive animal.
  • Toxic side-effects include:
    • Gastric irritation, progressing to vomiting, ulceration and hemorrhage.
    • Enteritis leading to diarrhea.
    • Blood dyscrasias.
    • Occasionally hepatotoxicity and/or nephrotoxicity.
    • Nephrotoxicity is more likely in dehydrated, hypovolemic or hypotensive animals, those undergoing anesthesia, or in animals being treated with other drugs which are potentially nephrotoxic. Use of NSAIDs should generally be avoided in these circumstances.
  • NSAIDs which have been reported to cause a high degree of toxicity and must not be used in the cat include:
    • Acetaminophen Paracetamol : this should be avoided in cats as they are deficient in glucuronyl transferase so toxic metabolites accumulate to cause severe hepatocellular necrosis and methaemoglobinemia.
    • Ibuprofen Ibuprofen poisoning.
    • Indomethacin.
    • Naproxen.
    • Phenylbutazone Phenylbutazone.
  • NSAIDs not licensed for use in cats and whose manufacturers do not recommend their use include:
    • Vedaprofen Vedaprofen.
    • Tepoxalin.
    • Firocoxib.
    • A dose for use of firocoxib acutely in cats has been published (McCann et al,2005) and there is a small amount of anecdotal evidence for the use of firocoxib (Previcox, Merial Animal Health) given orally at a dose of 1 mg/kg per day. This is 1/5 of the dog dose and so division of the available tablets is a major issue if attempting treatment in cats.
    • AspirinAcetyl salicylic acid has been established as a therapeutic agent in cats and is given at the dose of 10-25 mg/kg orally every 2-3 days. This may equate to 1/4 of a 300 mg tablet. One potential drawback to directing owners to use "off-the-shelf" aspirin is that they might substitute or accidentally use acetaminophen or ibuprofen products if they consider them to be equivalents for any reason and this possibility should be actively prevented by client education.
  • Licensed products are now available for short and long-term treatment of cats with NSAIDs. Off-licence use should be considered only when there is not a more appropriate treatment, the owner is fully informed and a consent form is signed and kept on file.
    • Tolfenamic acid Tolfenamic acid is only licensed to use as a single injection or for 3 days of oral tablets (licensed to treat febrile syndromes). 4 mg/kg daily orally with food for 3 days (Tolfedine injection 4%, Vetoquinol) (Tolfedine 6 mg tablets, Vetoquinol).
    • Ketoprofen Ketoprofen is licensed to use as a injection at 2 mg/kg SC once or orally for up to 5 days continuously 1 mg/kg. If a combination of injection and oral dosing is used then the maximum licensed duration of treatment is a total of 5 days (Ketofen 1%, Merial Animal Health Ltd).
    • Carprofen Carprofen despite being a good anti-inflammatory and potent analgesic agent this has much less inhibition on prostaglandin production than other NSAIDs. Therefore it is much safer to use in cats undergoing general anesthesia. It can be given at 4 mg/kg IV or SC as part of premedication or at induction of anesthesia to provide pre-emptive analgesia. It is only licensed for a single injection (Rimadyl Small Animal Injection, Pfizer Limited).
    • Meloxicam Meloxicam (Metacam 5 mg/ml solution for injection for dogs and cats) is licensed only for a single use SC injection at a dose of 0.3 mg/kg SC.
    • Meloxicam Meloxicam (Metacam 0.5 mg/ml oral suspension for cats, Boehringer Ingelheim), is licensed for indefinite use in cats that are benefiting from treatment. Initial treatment of a single dose of 0.1 mg/kg bodyweight orally or in food is continued at 0.05 mg/kg bodyweight per day, although lower doses or frequencies might be appropriate for some cats. The same precautions and contra-indications apply as for other NSAIDs and are detailed in the data sheet.
    • Robenacoxib (Onsior 6 mg tablets) Robenacoxib: COX1 sparing drug licensed for the management of pain associated with acute inflammation due to musculoskeletal disorders in cats. Licensed dose is 1 mg/kg daily administered for a maximum of 6 days. Tablets can be given with or without a small amount of food. Tablets can be crushed for administration with food, but they are not scored and therefore a whole tablet should be given to each cat.
    • Robenacoxib (Onsior 20 mg/ml solution): COX1 sparing drug licensed for the management of pain associated with soft tissue surgery in cats. Dose is 2 mg/kg bodyweight as a single injection, given approximately 45 minutes before induction of anesthesia. No current recommendation from the manufacturer regarding continued treament with tablet preparation after surgery in the UK. Injection followed by treatment with tablets (starting 24 hours later) for 11 days has Market Authorisation in Switzerland.

Further Reading

Publications

Refereed papers

  • Recent references from VetMed Resource and PubMed.
  • Giraudel J M, Toutain P L, King J N & Lees P (2009) Differential inhibition of cyclooxygenase isoenzymes in the cat by the NSAID robenacoxib. J Vet Pharmacol Ther 32, 31-40 PubMed.
  • Gunew M N, Menrath V H, Marshall R D (2008) Long term safety, efficacy and palatability of oral meloxicam at 0.01-0.03 mg/kg for treatment of osteoarthritic pain in cats. J Feline Med Surg 10, 235-241 PubMed.
  • McCann M E, Riches E L, Hora D F et al(2005) In vitro effects and in vivo efficacy of a novel cyclooxygenase-2 inhibitor in cats with lipopolysaccharide-induced pyrexia. Am J Vet Res 66, 1278-1284 PubMed.
  • Wallace J M (2003) Meloxicam. Comp Contin Educ Pract Vet 25, 64.
  • Matthews K A (2000 )Nonsteroidal anti-inflammatory analgesics. Indication and contraindications for pain management in dogs and cats. Vet Clin North Am Small Anim Pract 30, 783.
  • Johnson C (1999) Chemical restraint in the dog and cat. In Practice 21, 111-118.
  • Taylor P M (1985) Analgesia in the dog and cat. In Practice 7, 5-13.

Other sources of information

  • Plumb D C (2005) Veterinary Drug Handbook. Ames, Iowa, Iowa State University Press.
  • Tennant B (2005) BSAVA Small Animal Formulary. 5th edn, BSAVA, Quedgeley.
  • Hall L W and Taylor P M (1994) Eds Anaesthesia of the Cat. London: Bailliere Tindall. pp112-113, 116-118, 120-128. ISBN 0 7020 1665 9
  • Nolan A M (1989) Analgesia. In: Manual of Anaesthesia for Small Animal Practice. Ed A D R Hilbery. Cheltenham: British Small Animal Veterinary Association. pp33-38. ISBN 0 905214 09 9.


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