Introduction

Name

• Diltiazem.

Class of drug

• Class IV antidysrhythmic agent.
• Calcium channel blocker.

Uses

Indications

• To control supraventricular tachycardias.
• Sustained and paroxysmal ventricular tachycardias Ventricular premature contraction particularly in cases of hypertrophic cardiomyopathy Heart: hypertrophic cardiomyopathy (HCM).
• To slow heart rate in dogs with atrial fibrillation Heart: atrial fibrillation as an adjunct to digoxin.

• Management of hypertension Hypertension.
• To limit CNS damage following trauma.

• Preferred to verapamil by many because it has effective antiarrhythmic properties with minimal negative inotropy.
• Calcium channel blockers are preferred to propranolol for the management of feline hypertrophic cardiomyopathy by some authors because they improve myocardial relaxation, increases ventricular filling and dilate coronary vasculature.

Administration

Pharmacokinetics

Precautions

Interactions

with other drugs

• If administered concurrently with propranolol Propranolol there may be additive negative inotropic and chronotropic effects.

• Diltiazem's activity may be adversely affected Vitamin D Calcium carbonate Calcium chloride.

• Plasma concentrations increased by diltiazem Digoxin Digitoxin.
• Monitoring of digoxin serum levels is recommended.

• Cimetidine Cimetidine inhibits the metabolism of diltiazem thereby increasing plasma concentrations.

• Diltiazem enhances the effect, which may lead to toxicity Theophylline.

• Diltiazem may displace warfarin Warfarin.

• Diltiazem may increase intracellular levels by inhibiting the drug's outflow from the cell Vincristine.

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.

Other sources of information

• Based on Small Animal Formulary. Tennant, Bryn (1999) 3rd edn. Cheltenham: BSAVA.