| Enalapril
for Cardiomyopathy and CHF
“Enalapril maleate is an angiotensin-converting
enzyme (ACE) inhibitor labeled to treat mild to
severe heart failure in dogs.” Research
has shown that enalapril in combination with diuretics
- with or without digitalis glycosides - “produces
statistically significant clinical improvement
in dogs with advanced heart failure due to mitral
regurgitation or dilated cardiomyopathy”
and has demonstrated “beneficial hemodynamic
and clinical effects of adding enalapril to conventional
therapy for dogs with CHF... Dogs treated with
enalapril and conventional CHF therapy survived
two times as long as did those receiving standard
therapy alone.”
Enalapril has also “been effective in treating
cardiomyopathy and CHF in cats and ferrets, and
its effects on blood pressure in horses and camels
have been studied.” Because enalapril is
a prodrug and can not be converted to its active
form enalaprilat in patients with severe liver
dysfunction, captopril or lisinopril might be
a better choice in those patients. Renal function
should be checked before starting enalapril therapy
and at least every two months thereafter. The
most common side effects are gastrointestinal,
but there have been reports of enalapril-induced
cough in dogs and a bird. Hypotension is a major
concern if overdose occurs. NSAIDs, including
aspirin, may reduce enalapril’s effect.
The injectable form (enalaprilat) should not be
given orally because it is very poorly absorbed.
“The recommended dose for enalapril in dogs
is 0.5 mg/kg orally every 12 to 24 hours. The
dose for cats is 0.25 to 0.5 mg/kg orally every
12 to 24 hours.”
Compendium, Dec. 1999
Amlodipine to Treat Feline
Systemic Hypertension
Amlodipine, a calcium channel blocker,
has an antihypertensive effect in cats with coexistent
systemic hypertension and renal insufficiency.
Its use may improve the prognosis for cats with
systemic hypertension by decreasing the risk of
ocular injury or neurologic complications induced
by high blood pressure (BP). In a retrospective
study, medical records from 69 cats with systemic
hypertension and hypertensive retinopathy were
reviewed. 68.1% of the cats were referred because
of vision loss; retinal detachment, hemorrhage,
edema, and degeneration were common findings.
Amlodipine decreased BP in 31 of 32 cats and improved
ocular signs in 18 of 26 cats. Primary hypertension
in cats may be more common than currently recognized.
In a study at the Department of Small Animal Clinical
Sciences, College of Veterinary Medicine, University
of Florida, amlodipine was shown to be a safe
and effective once-daily antihypertensive agent
when administered to cats at a dosage of 0.18
+/- 0.03 mg/kg daily as monotherapy. Researchers
at the Department of Medical Sciences, University
of Wisconsin-Madison, administered amlodipine
at an oral daily dosage of 0.625 mg per cat (range
= 0.08 to 0.23 mg/kg body weight). Average indirect
systolic blood pressure measurements in those
12 cases decreased significantly from 198 to 155
mmHg during amlodipine treatment. Significant
changes in body weight and serum creatinine and
potassium concentrations were not detected.
Relationship between ocular
lesions and hypertension
Retinal lesions, caused predominantly by choroidal
injury, are common in cats with hypertension.
Hypertension should be considered in older cats
with acute onset of blindness; retinal edema,
hemorrhage, or detachment; cardiac disease; or
neurologic abnormalities. Cats with hypertension-induced
ocular disease should be evaluated for renal failure,
hyperthyroidism, diabetes mellitus, and cardiac
abnormalities. Blood pressure measurements and
funduscopic evaluations should be performed routinely
in cats at risk for hypertension (preexisting
renal disease, hyperthyroidism, and age > 10
years).
Am J Vet Res 2002 Jun;63(6):833-9
Click here to access the PubMed abstract of this article.
J Am Vet Med Assoc 2000 Sep 1;217(5):695-702
Click here to access the PubMed abstract of this article.
J Vet Intern Med 1998 May-Jun;12(3):157-62
Click here to access the PubMed abstract of this article.
J Am Anim Hosp Assoc 1997 May-Jun;33(3):226-34
Click here to access the PubMed abstract of this article. |
