• anti-arrhythmia agent;
  • anti-hypertensive agent;
  • calcium channel antagonist receptor;
  • calcium channel blocker receptor;
  • exogenous calcium antagonists;
  • vasodilator agent


Objective: Calcium channel blockers (CCB) are frequently prescribed for veterinary patients and the incidence of toxicosis secondary to these agents is increasing. The purpose of this review is to discuss toxicity of these agents and review therapeutic options.

Etiology: Calcium plays a vital role in maintaining cellular functions within the cardiovascular system. Toxicosis secondary to these drugs can have deleterious effects on vascular tone, cardiac contractility, as well as electrical conduction in the heart.

Diagnosis: The intitial diagnosis is often made based on history of ingestion, physical examination and electrocardiography. Definitive diagnosis of CCB overdose can be made via quantification of serum concentrations of the drug ingested.

Therapy: Initial therapy should consist of inducing emesis and administration of activated charcoal. Other potential therapies include intravenous calcium, parasympatholytics, sympathomimetics, glucagon, insulin and dextrose, placement of a temporary pacemaker, or calcium channel agonists.

Prognosis: There is little data on the outcome of CCB toxicosis. Aggressive management of these cases is necessary to try and minimize morbidity and mortality.