Diltiazem belongs to a general class of drugs known as calcium channel blockers, inhibiting the entry of calcium into heart muscle cells by partially blocking some of the calcium channels. This reduces the strength of contraction in heart muscle cells. In blood vessels, calcium channel blockers prevent calcium entry, leading to widening of the arteries, which lowers blood pressure and reduces the resistance to ejection of blood from the heart. Diltiazem also affects electrical activity in the heart by slowing the heartbeat and delaying electrical conduction across the tissues between the upper chambers (atria) and lower chambers (ventricle). This drug is not approved for use in animals by the Food and Drug Administration but it is prescribed legally by veterinarians as an extra-label drug.
Who's Diltiazem For?
- Primarily used for treatment (and sometimes prevention) of cardiac arrhythmias, including atrial fibrullation, atrial flutter and supraventricular tachycardia
- Used in managing the heart muscle disease hypertrophic cardiomyopathy in some cats
- Diltiazem can lower high blood pressure. However, other calcium channel blockers are more effective for this purpose
Side Effects and Warnings
- Diltiazem should not be used in animals with known hypersensitivity or allergy to the drug
- Diltiazem may interact with other medications including digoxin, propranolol, cimetidine and cyclosporin. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with diltiazem
- This drug may relax blood vessels or depress the heart rate, or contraction, to such a degree that some animals become weak due to low blood pressure
- Side effects include vomiting, diarrhea, loss of appetite and a slow heart rate. Any symptoms should be reported to your veterinarian
- Take care when giving diltiazem to animals with heart failure. High doses can depress heart muscle function. Side effects are more likely when Diltiazem is administered with other potent cardiovascular drugs, such as diuretic or other vasodilators (drugs that act to relax blood vessels)
- Consult your veterinarian regarding any allergies your pet may have, and any other side effects of this medication
Use as directed by your veterinarian