Vasopressor Use, Critical Care Management, and Outcomes in Dihydropyridine Calcium Channel Blocker Toxicity

Abstract

Introduction: Although dihydropyridine calcium channel blockers (DHP CCBs) are considered to have less direct myocardial toxicity than non-dihydropyridines, DHPs remain a common cause of morbidity and mortality. We sought to examine various indices of critical illness and describe the clinical course of a population of DHP CCB-poisoned patients with special attention to vasopressor dosing and ischemic complications.

Methods: This is a retrospective chart review of DHP CCB exposures admitted to a single center. The study site was a single tertiary referral center with an in-house medical toxicology consultation/admitting service. Inclusion criteria included age ≥ 14 years and DHP ingestion noted on departmental patient log. Patients were excluded if DHP exposure was not documented in the medical record. The study period ranged from July 1, 2010 through December 31, 2022. Data on clinical presentation, management, and outcomes were reported.

Results: Sixty-eight cases of DHP exposure were analyzed; 87% were intentional ingestions. Amlodipine represented 88% of cases. 85% included cases involved co-ingestions. Vasopressors were administered in 42 cases (62%), with a median of three agents (IQR 1-4). Norepinephrine was most common (N = 41; 98%), followed by epinephrine (N = 23; 55%); median maximal rates were 45.0 (IQR 13.5-70.0) and 25.0 (IQR 12.0-30.0) mcg/min, respectively. 15% (N = 10) received high dose insulin-euglycemic therapy (HIE); all had > 2 vasopressors administered before administration of HIE. Twelve (18%) patients had ischemic complications; five (7%) experienced ischemic complications not evident before vasopressor administration. There were five deaths (7%).

Conclusions: Multiple vasopressor use was common in this population of patients with DHP CCB toxicity. Despite the high doses of vasopressors used, temporally related ischemic complications were uncommon.

Keywords: 1,4-dihydropyridine; Calcium channel blockers; Cardiotoxicity; Drug overdose; Vasoconstrictor agents.