Plasma Concentrations of Diltiazem and Desacetyldiltiazem in an Overdose Situation

Abstract

OBJECTIVE: To describe the elimination of diltiazem and desacetyldiltiazem in an overdose situation. CASE SUMMARY: An 18-year-old woman ingested controlled delivery diltiazem 14.94 g in a suicide attempt. After arriving at the hospital unresponsive and hypotensive, her condition progressed to complete heart block, cardiogenic shock, asystole, and acute renal failure. Supportive care consisted of vasopressors, intravenous calcium, intravenous glucagon, charcoal hemoperfusion, temporary transvenous pacing, and an intraaortic balloon pump. After 12 days in the hospital, the patient recovered fully. DISCUSSION: We report a large, documented overdose of diltiazem and detail the pharmacokinetic profiles of both diltiazem and its active metabolite, desacetyldiltiazem. Nonlinear elimination of diltiazem appears to occur at higher concentrations. Although the patient improved clinically following charcoal hemoperfusion, no dramatic effects on diltiazem elimination were apparent. CONCLUSIONS: Survival following massive diltiazem overdose can be achieved with supportive care. Charcoal hemoperfusion had a limited effect on improving the clearance of diltiazem as evidenced by serial plasma concentrations.