Poisoning with anti-hypertensive drugs: calcium antagonists

Calcium antagonists are used increasingly to treat hypertension and other conditions, so the possibility of accidental or deliberate self-poisoning is substantially increased. These drugs account for a high proportion of deaths in cases of poisoning associated with cardiovascular drugs. Most of our present knowledge is with the older calcium antagonists, namely verapamil, nifedipine and diltiazem; newer sustained-release preparations of these drugs may produce serious toxicity in patients who initially appear well. This review discusses the cases reported in the literature, the presenting symptoms and the management of patients with calcium antagonist poisoning.