Page 657 - Small Animal Internal Medicine, 6th Edition

CHAPTER 37 The Exocrine Pancreas 629

because their pain is difficult to assess. Morphine agonists have often been cited with regard to dogs and humans,
or partial agonists are often used, particularly buprenorphine but more recent studies have suggested minimal clinically
VetBooks.ir or butorphanol. Butorphanol also has antiemetic properties. relevant effects, except when high and repeated doses of
morphine are used. These drugs are regularly used now in
These partial opiate agonists are effective for mild to moder-
ate pain, but full opioid agonists are preferred in more severe
tanyl patches take time to achieve effect (on average, 24 hours
pain. Morphine, methadone, meperidine, and fentanyl (IV or humans with pancreatitis, with no obvious problems. Fen-
patches) can be used (Table 37.4). Concerns that the effects in dogs and 7 hours in cats), so concurrent use of an opiate
of opiates on the sphincter of Oddi might exacerbate disease for the first few hours after application is recommended.

TABLE 37.4
Analgesics Used for Acute Pancreatitis

INDICATIONS AND DOSAGE AND ROUTE
ANALGESIC CAUTIONS DOGS CATS COMMENTS
Buprenorphine Most generally useful IV, SC, IM, 0.01- IV, SC, IM same Concerns about effects
analgesic in hospitalized 0.02 mg/kg as for dogs on sphincter of Oddi
patient Oral transmucosal Oral transmucosal largely unfounded
May be dosed transmucosally dose 0.12 mg/kg dose 0.01-
at home in both dogs and 0.03 mg/kg*
cats but dog dose much
higher
Butorphanol Author has limited experience 0.05-0.6 mg/kg IM, Same as for dogs At analgesic doses in
with its use; other opiates SC, IV, q6-8h; humans, increases
preferred in acute 0.1-0.2 mg/kg/h pulmonary artery
pancreatitis because of as CRI pressure and cardiac
butorphanol’s limited Oral—0.5-1 mg/kg work, unlike other
analgesic effect and q6-12h analgesics in the table,
potentially negative so other opiates
cardiovascular effects (see preferred
notes); however, additional
antiemetic effect may be
beneficial
Meperidine Meperidine by injection only, 5 mg/kg SC, IM, 3-5 mg/kg SC, Painful on injection
(Demerol) hence hospitalized animals q2h IM, q2h Derived from atropine;
Not for IV administration therefore, in contrast to
(causes histamine release other opioids, is
and results in profound spasmolytic agent on
hypotension) smooth muscle; might
be useful for the gut
Morphine Vomiting common 0.1-0.5 mg/kg SC, 0.1-0.2 mg/kg Stimulation of sphincter of
Useful for severe acute pain, IM, IV, 0.1 mg/ SC, IM, IV Oddi reported in
can be given by slow IV kg/h by constant humans but of dubious
injection to effect rate infusion relevance for dogs and
cats
Methadone Little nausea or vomiting, so 0.2-0.4 mg/kg SC, 0.2 mg/kg SC, Can produce dysphoria
more useful than morphine IM, q4-6h or as IM, q4-6h or as May get increased
required required duration of action with
repeated doses
Hydromorphone 0.05 mg/kg IV q4h; 0.1 mg/kg IM Can produce dysphoria
0.1-0.4 mg/kg IM q7h
Fentanyl patch Very useful, but take great 2-4 µg/kg/h patch 25 µg/h patch 24-hour onset and
care if sending home with with half 72-hour duration in
patch exposed dogs; 7-hour onset and
72-hour duration in
cats
Continued