Page 422 - Feline Cardiology

Generic Name Indications/Drug Dosage and Comments Available sizes
(Brand Name) Type Possible Routes
of Admin.

Dilacor—see

Diltiazem Calcium-channel 10 mg/kg PO Hypertrophic cardiomyopathy. Convenience of 60, 90,
sustained release blocker, non- PO q 24h once- daily dosage now appears outweighed 120,180,
(Cardizem CD, dihydropyridine (Dilacor, by erratic bioavailability in the cat and 240, 360,
Dilacor XL [both type compounded); reversible but severe adverse effects including 420 mg ER
H] ) or anorexia, vomiting, lethargy, weight loss, and Cap
30 mg/cat PO evidence of hepatopathy in a substantial HM
q 24h proportion of treated cats in 2 independent
(Cardizem CD) studies, and lack of demonstrable efficacy.
Diltiazem HCl Calcium-channel 1.75–2.4 mg/ Hypertrophic cardiomyopathy. Shown to 30,60,
(Cardizem [H]) blocker, non- kg PO improve clinical signs in the original feline 90,120 mg
dihydropyridine q 8h HCM study (ref. Bright); appropriate for HCM Tab
type if antitachycardia effects (which are less HM
pronounced with calcium channel blockers)
are not necessary and three-times daily
medication administration is acceptable. May
be less effective than atenolol for reducing
severity of left ventricular outflow tract
obstruction in cats with HOCM. Often
replaced by atenolol (q 12–24h dosing).

Diltiazem IV Calcium-channel 0.125– Severe (HR > 300/min), persistent atrial 5 mg/ml
(Cardizem [H]) blocker, non- 0.35 mg/kg tachycardias. Risk of acute bradycardia and Inj
dihydropyridine slow hypotension warrants judicious uptitration: HM
type IV bolus administer low dose and monitor for effect,
(1–2 minutes); then repeat if needed. Adjunct measures (e.g.,
PRN reduction of anxiety and other sources of
sympathetic stimulation) are essential.
Contraindicated in sinus tachycardia (find and
manage underlying cause) and all
bradycardias.
Disal—see
Furosemide
Continued

447 Drug Formulary