CALCIUM-CHANNEL BLOCKING DRUG OVERDOSE - AN AUSTRALIAN SERIES

1 A descriptive case study of calcium channel-blocking drug (CCB) over doses in the Hunter Region of NSW was performed to analyse the in-hosp ital morbidity and mortality of CCB drug overdoses in an Australian po pulation. 2 The patients were admitted to major hospitals within the H unter Region and treated initially with gastrointestinal decontaminati on, including the use of oral activated charcoal. Further management w as required in most cases and included intravenous calcium, atropine a nd inotropic support. 3 Of the 15 CCB overdoses, four patients died. N oncardiogenic pulmonary oedema occurred in two other cases. Cardiac co nduction defects occurred in 11 cases. 4 Atropine was found to be effe ctive only after intravenous calcium had been administered. 5 Overdose with slow-release verapamil required prolonged treatment with intrave nous calcium salts. 6 Overdose with verapamil or diltiazem in doses gr eater than 300 mg carries a significant risk of death and potentially life threatening arrhythmias occur with lower doses. 7 Recommended ini tial management includes early, effective gastrointestinal decontamina tion, High dose intravenous calcium salts should be given to reverse h ypotension and bradycardia. Atropine and inotropic support are frequen tly required.