Calcium channel blocker (CCB) overdose can lead to severe shock/hypotension. A small study was conducted to compare the hemodynamic effects of high-dose insulin (HDI) for two classes of CCB (dihydropyridines vs. non-dihydropyridines) that work differently to manage hypertension.   

Study design:

• Retrospective study from a single poison center (2019 – 2021)

Study sample:

• Amlodipine poisoning cases: 18
• Non-dihydropyridine (non-DHP) poisoning cases: 15

Result

Median number of maximum concomitant vasopressors (p=0.04)

• Amlodipine: 3 (IQR: 2-5; range 0-6)
• Non-DHP: 2 (IQR: 1-3; range 0-5)

Median difference in max concomitant vasopressors: 1 (95% CI: 0 – 2)

Median max epinephrine dosing

• Amlodipine: 0.31 mcg/kg/min
• Non-DHP: 0.09 mcg/kg/min

Use of rescue methylene blue (p=0.009)

• Amlodipine: 7/18 (39%)
• Non-DHP: 0

Conclusion:

• Amlodipine poisoning on HDI required more vasopressors and higher doses of epinephrine compared to non-DHP (verapamil or diltiazem)
• This may be due to vasodilatory effect of amlodipine compared to non-DHPs

References

Cole JB, Lee SC, Prekker ME, Kunzler NM, Considine KA, Driver BE, Puskarich MA, Olives TD. Vasodilation in patients with calcium channel blocker poisoning treated with high-dose insulin: a comparison of amlodipine versus non-dihydropyridines. Clin Toxicol (Phila). 2022 Nov;60(11):1205-1213. doi: 10.1080/15563650.2022.2131565. Epub 2022 Oct 25. PMID: 36282196.