Using Diltiazem, Generic of Tiazac & Cardizem How Blocking Calcium Channels Can Help Your Pet's Heart Condition

BY | September 23 PUBLISHED BY
Heart Failure Heart Disease
Indications for Diltiazem

A calcium channel blocker, diltiazem works by preventing calcium from building up in blood vessels, which makes it easier for blood to flow, thereby lowering blood pressure. Useful in the treatment of cardiac arrhythmias, hypertrophic cardiomyopathy, or just lowering high blood pressure (although other drugs are more effective at lowering blood pressure), diltiazem is one of the most prescribed drugs for the treatment of heart disease. Although originally designed for use in people, it can legally be prescribed as an ‘extra-label’ drug for pets by your vet.


Pets with severe hypotension, sick sinus syndrome, 2nd or 3rd degree AV block, acute myocardial infarction, or pulmonary congestion should not take diltiazem. Elderly pets, pets taking beta blockers, or pets with liver or kidney failure should take diltiazem with caution. Due to the potential teratogenic qualities of diltiazem, it should only be given to pregnant pets if the benefits outweigh the risks to the baby. Pets taking diltiazem with cyclosporine, digoxin, or quinidine should be monitored closely, as the levels of diltiazem may be affected. Cimetidine and ranitidine might cause an increase in the plasma levels of diltiazem. Diltiazem might increase the bioavailability of propranolol.


Dog -- 0.125 - 0.35 mg/kg IV or 0.5 - 1.5 mg/kg orally, every 8 hours
Cat -- 0.125 - 0.35 mg/kg IV or 7.5 mg orally every 8-12 hours

Side Effects

The most common side effect of diltiazem is bradycardia, but other side effects, such as vomiting, diarrhea, depression, and loss of appetite, are possible. Hypotension, heart block, arrhythmias, central nervous system effects, and elevated liver enzymes are also possible, but rare.

Brand/Generic Equivalents

Cardizem, Tiazac

Related Medication Guides

You May Also Like