Pain management in cats—past, present and future. Part 2. Treatment of pain—clinical pharmacology

Abstract

Opioids have an unjustified reputation for causing mania in cats, but with refinements in dosing they are now used successfully in this species. The mu-opioid agonists are generally considered the best analgesics. Morphine (0.1-0.3 mg/kg) is effective in a clinical setting. Methadone (up to 0.5 mg/kg) has a similar profile to morphine. Pethidine (Demerol, meperidine; 2-5 mg/kg) is a useful analgesic with a faster onset but shorter duration of action than morphine. Oxymorphone and hydromorphone (0.05-0.1 mg/kg) are widely used in the USA. These opioids are more potent (up to 10 times), and longer acting than morphine in cats. Butorphanol (0.1-0.4 mg/kg) is a mu-opioid antagonist that produces its analgesic actions through kappa agonist activity. It rapidly reaches a ceiling effect, is short acting and is a weaker analgesic than pure mu opioids. Buprenorphine (0.01-0.02 mg/kg), a partial mu-agonist, is the most popular opioid used in small animal practice in the UK, other parts of Europe, Australia and South Africa. In clinical studies it has produced better analgesia than several other opioids and appears to be highly suitable for perioperative pain management in cats. NSAIDs are also used in cats for pain management, although cats metabolise these differently from other species. With appropriate dosing, carprofen (1-4 mg/kg) and meloxicam (0.3 mg/kg) have proved highly effective with few side effects. The use of ketoprofen (2 mg/kg), tolfenamic acid (4 mg/kg) and vedaprofen (0.5 mg/kg) has been reported in cats. Other less traditional analgesics such as ketamine, medetomidine and local anaesthetics are also used for clinical pain management. The transmucosal, transdermal and epidural routes offer novel methods for administration of analgesic drugs and have considerable potential for improving techniques in feline pain management.

Effect Of Three Anesthetic Protocols On The Haematological Indices In Cats During Ovariohysterectomy

“…The preoperative application of meloxicam reduces the systemic stress response, by decreasing the plasma cortisol and adrenaline (17,18). The peak of the analgesic effect of butorphanol is between the 30th and 60th min of intramuscular application (19), which corresponded to the lowest detected WBC, Ly, Gran in group ММ, in agreement with data from earlier research of ours regarding the blood hormonal levels in the same periods (9).…”

Comparison of peribulbar and retrobulbar regional anesthesia with bupivacaine in cats

“…23,34 The volumes for RBA and PBA in the present study were based on results for a study 26 in cat cadavers, where 1 and 4 mL resulted in appropriate intraconal distribution. However, although results of that study 26 indicated 4 mL was appropriate for PBA, a volume of 3 mL was used in the present study because of 2 concerns: ensuring we did not exceed a bupivacaine dose of 2 mg/kg to avoid systemic toxicosis, [35][36][37][38][39][40][41] and maintaining a bupivacaine concentration > 0.25% because lower concentrations of the anesthetic may lead to decreased efficacy. 4,42,43 Given that distribution of the injectate around the optic nerve was only 90° to 180° in 3 of 6 PBA-treated eyes, it is possible that a larger volume (4 mL) was indicated for PBA.…”

Adjuvant Immunotherapy of Feline Fibrosarcoma with Recombinant Feline Interferon‐ω

“…51,52 Nonsteroidal anti-inflammatory drugs also have been beneficial in the treatment of transitional-cell carcinoma in dogs. 53 These substances not only decrease the inflammatory reaction in the tumor tissue but also inhibit tumor growth.…”