Page 315 - Withrow and MacEwen's Small Animal Clinical Oncology, 6th Edition

CHAPTER 16 Supportive Care for the Cancer Patient 293

TABLE 16.5 Suggested Dosages of Analgesics to Alleviate Chronic Cancer Pain in Cats a
Drug Dosage (mg/kg) Notes
VetBooks.ir Paracetamol (acetaminophen) Contraindicated Contraindicated – small doses rapidly cause death in cats.

3–5 mg/kg PO q24hrs
This drug has not been evaluated for toxicity but is well tolerated in dogs and
Amantadine
humans, with occasional side effects of agitation and GI irritation. May be a
useful addition to NSAIDs in the treatment of chronic cancer pain conditions.
Amantadine powder can be purchased and formulated into appropriately
sized capsules. The kinetics have recently been evaluated in cats.
Amitriptyline 0.5–2 mg/kg PO q24hrs This drug appears to be well tolerated for up to 12 months of daily adminis-
tration. May be a useful addition to NSAIDs for treatment of chronic pain
conditions.
Aspirin 10 mg/kg PO q48hrs Can cause significant gastrointestinal ulceration.
Buprenorphine 0.01–0.02 mg/kg sublingual q8–12hrs The sublingual route is not resented by cats and may be a good way to provide
postoperative analgesia at home. Feedback from owners indicates that after
2–3 days dosing at this dosage, anorexia develops. Smaller doses (5–10 mcg/
kg) may be more appropriate for long-term administration, especially in
combination with other drugs.
Butorphanol 0.2–1 mg/kg PO q6hrs One study suggests that using oral butorphanol after surgery may be beneficial.
Generally considered to be a poor analgesic in cats except for visceral pain,
but the author has found it to be useful as part of a multimodal approach to
cancer pain therapy.
Carprofen Not enough data to enable recommen- —
dations for long-term administration
Etodolac Not recommended —
Firocoxib — Use has not been reported in clinical cases; however, firocoxib has a half-life of
8–12 hours in the cat, and at 3 mg/kg provided antipyretic effects in a
pyrexia model.
Flunixin meglumine 1 mg/kg PO daily for 7 days Daily dosing for 7 days results in an increased rate of metabolism of the drug;
however, a rise in liver enzymes suggests that liver toxicity may be a problem
with prolonged dosing.
Gabapentin 10 mg/kg q12hrs Appears to be particularly effective in chronic pain in cats when an increase in
sensitivity has occurred or when the pain appears to be excessive compared
to the lesion present.
Ketoprofen 1 mg/kg PO q24hrs Probably well tolerated as pulse therapy for chronic pain, with approximately 5
days of “rest” between treatments. Has also been used by some long term
at a dosage of 1 mg/kg every 3 days.
Another approach has been to use 0.5 mg/kg daily for 5 days (weekdays), and
then no drug over the weekend, with this regimen repeated.
Meloxicam 0.1 mg/kg PO on day 1; then 0.05 mg/ The liquid formulation makes it very easy to gradually and accurately reduce the
kg PO daily for 4 days; then 0.05 dosage. However, a decreasing regimen (as suggested here) has not been
mg/kg every other day thereafter evaluated for efficacy in cats, although it has been found to be successful in
(approved in the EU at 0.05 mg/kg dogs. The lowest dosage that has been demonstrated to be effective (in osteo-
daily indefinitely for musculoskeletal arthritis pain) is 0.035 mg/kg/day.
pain) Meloxicam should be dosed accurately using syringes.
Piroxicam 1 mg/cat PO daily for a maximum of 7 Daily dosing for 7 days results in a slight increase in the half-life.
days. If longer term medication is
considered, suggest every other day
dosing
Prednisolone 0.5–1 mg/kg PO q24hrs Can be very effective. NOT to be combined with concurrent NSAID
administration.

Prednisone 0.5–1 mg/kg PO q24hrs Can be very effective. NOT to be combined with concurrent NSAID adminis-
tration. In animals with diminished liver function, prednisolone may be more
appropriate.
Continued