Page 674 - Small Animal Internal Medicine, 6th Edition

646 PART IV Hepatobiliary and Exocrine Pancreatic Disorders

VetBooks.ir Drugs Used for Hepatobiliary and Pancreatic Disorders—cont’d INDICATIONS AND COMMENTS

DOSAGE
DRUG NAME (TRADE NAME)
Antioxidants
S-adenosylmethionine (SAM-e) Dogs—20 mg/kg (or more) Indicated for any liver disease, but particularly hepatic
(Denosyl) PO q24h lipidosis in cats and toxic hepatitis and diseases
Cats—20 mg/kg or causing biliary stasis in dogs and cats
200-400 mg total daily Tablets must be given whole on empty stomach for
effective absorption
Sylmarin (silymarin, silibin) 50-200 mg/kg PO q24h, for Antioxidant derived from milk thistle
dogs Likely safe, but efficacy unknown as very limited
studies on which to base dose advice for dogs;
studies were in toxic hepatitis
Vitamin E (tocopherol) 400 IU/day for medium-sized Indications as for SAM-e but including any chronic
dogs (titrate accordingly for hepatitis in dogs
other sizes); 5-25 IU/kg PO
daily, dogs and cats
Zinc (see copper-chelating
agents) and ursodeoxycholic
acid (see choleretic); also has
antioxidant activities
Antidotes
N-acetylcysteine Cats and dogs—140 mg/kg Antidote for acetaminophen toxicity that binds toxic
IV or PO as loading dose; metabolite and increases glucuronidation process
then continued at 70 mg/kg Can cause nausea and vomiting when given orally
q6h for total of seven Foul taste makes oral dosing difficult without
treatments or for up to 5 nasogastric tube
days
Cimetidine Dogs—5-10 mg/kg IV, IM, Slows oxidative hepatic drug metabolism by binding to
PO, q6-8h microsomal cytochrome P-450, so useful additional
Cats—2.5-5 mg/kg IV, IM, antidote for acetaminophen toxicity in dogs and cats
PO, q8-12h
Antioxidants (e.g., See sections on antioxidants
S-adenosylmethionine) and and vitamins
vitamins E and C also
supportive for oxidant toxins
such as acetaminophen
Antiulcer Treatment
Ranitidine (Zantac) 2 mg/kg PO or slowly IV Acid secretory inhibitor of choice in liver disease
q12h, dogs and cats May not be necessary if gastric pH is high
Cimetidine should be avoided because of action on
cytochrome P-450 enzymes, except as antidote (see
earlier)
Sucralfate (Carafate) Dogs—1 g/30 kg PO q6h Gastric ulceration associated with liver or pancreatic
Cats—250 mg/cat PO q8-12h disease
Copper-Chelating Agents
Penicillamine Dogs only—10-15 mg/kg PO Copper chelator of choice for copper storage disease;
q12h takes months to remove copper from liver
Give on an empty stomach; vomiting common
Immune-mediated, renal, and skin disease possible