Disopyramide (Norpace)-induced hypoglycemia.

Disopyramide (Norpace) is a recently released antiarrhythmic agent with quinidine-like actions, but structurally unique. We describe a patient in whom impressive hypoglycemia developed following treatment with this agent. Blood glucose levels returned to normal after cessation of therapy, but dropped again following rechallenge with the drug. The pathogenesis of the hypoglycemia was investigated by assessment of serum insulin, plasma glucagon and serum alanine levels during disopyramide rechallenge. Clinicians should be aware of fasting hypoglycemia as an unusual but potentially serious complication of disopyramide therapy.