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Veterinary : Pain Management
Pain Management in Cats
Pharmacokinetic data developed in other species
cannot be safely extrapolated to the cat. Feline deficiency of glucuronidation
pathways results in slow metabolism of several NSAIDs, which prolongs
the duration of effect and may lead to drug accumulation and toxicity.
Meloxicam, a COX2 selective NSAID, has demonstrated
clinical efficacy for chronic pain, musculoskeletal pain, and routine
soft tissue surgery with few side effects. Based on clinical experience,
Lascelles of NCSU College of Veterinary Medicine, now recommends
oral meloxicam doses for cats that are less than previously reported
in the literature (0.1 mg/kg PO on day 1 followed by 0.05 mg/kg PO
daily for 4-6 days, then 0.025 mg/kg daily for 10 days, then lowest
effective dose).1
Five days of oral treatment with meloxicam or
ketoprofen for cats with painful locomotor disorders provided similar
analgesia2, but meloxicam drops were more palatable than ketoprofen
tablets. Appropriately flavored preparations in a convenient dosage
form are easier for owners to administer and allow for accurate dosing.
According to Robertson and Taylor3, 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. 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. 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.
Amitriptyline (starting dose 2.5 mg/kg PO, once
daily) has been used to treat feline interstitial cystitis with few
side effects, and there are anecdotal reports of its use for cancer
and neuropathic pain management.
Some of the less conventional analgesics including
the tricyclic anti-depressants and gabapentin may prove to play a
useful role in chronic pain management, but controlled clinical trials
are needed to establish the best doses for maximum efficacy. Other
less traditional analgesics such as ketamine and local anesthetics
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.
1 www.vetmash.com/dr_duncan_lascelle04.pdf,
accessed Nov 2004
2J Small Anim Pract 2001 Dec;42(12):587-93
Click
here to access the PubMed abstract of this article.
3Journal of Feline Medicine and Surgery; 6(5), Oct 2004:
321-333
Meloxicam for Analgesia in Dogs
A clinical trial was conducted to evaluate the
safety and efficacy of meloxicam in dogs with chronic osteoarthritis.
A scoring system assessed specific lameness, general stiffness, painful
rise, exercise intolerance, and behavior, and demonstrated significant
reductions in clinical signs of osteoarthritis following 4 weeks
of drug therapy. Side effects were minimal in extent and duration.
The findings of this investigation suggest that the efficacy, tolerance,
and formulation of meloxicam oral suspension make it well suited
for the treatment of chronic osteoarthritis in the dog.
Can Vet J 2000 Apr;41(4):296-300
Ketoprofen
is a potent anti-inflammatory and analgesic which can be used for
the management of surgical pain or chronic pain. The drug should
not be given to animals with GI ulceration, impaired renal or hepatic
function, or coagulation disorders. Ketoprofen should not be used
preoperatively when noncompressible bleeding may be a problem. Occasional
vomiting has been reported. When an NSAID or other drug that is potentially
irritating to the GI tract is needed, topical preparations offer
an excellent alternative. Pharmaceutical Research, Vol. 13, No.
1, 1996 reports (in humans) “a topical formulation
of ketoprofen has been developed for the temporary relief
of minor aches and pains of muscle and joints and to minimize gastrointestinal
side effects after oral administration.”
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