A Case of Life-threatening Amlodipine and Atenolol Overdose

Effective Management of Severe Amlodipine/Atenolol Overdose with Intravenous Calcium, Hyperinsulinemic Euglycemia Therapy, and Continuous Veno-Venous Hemodialysis: A Case Report

BACKGROUND Amlodipine, a calcium channel blocker, and atenolol, a beta blocker, are commonly used as a fixed drug combination (FDC) to treat hypertension. Intentional or non-intentional overdose of amlodipine-atenolol results in hypotension and myocardial depression with a high risk of mortality. This report describes a 64-year-old man with an overdose of amlodipine-atenolol, presenting as an emergency with hypotension, bradycardia, and severe metabolic acidosis. He was successfully treated with intravenous calcium chloride infusion, hyperinsulinemia euglycemia therapy (HIE), and continuous veno-venous hemodialysis (CVVHD). CASE REPORT A 64-year-old man was diagnosed with essential hypertension 1 week prior to the admission. He had been prescribed 1 FDC tablet of amlodipine and atenolol (5+50 mg) per day; however, he took 1 table of the FDC per day for 3 days and then took 3-4 tablets each day during the next 4 days. He was brought to the hospital with hypotension, bradycardia, and severe metabolic acidosis and was diagnosed with amlodipine-atenolol overdose. He was treated with intravenous calcium chloride infusion, HIE, and CVVHD. His hemodynamics started to improve after administering these therapies for 6 h. Inotropes were gradually tapered off and stopped. He was extubated on day 5 and recovered completely. CONCLUSIONS This report shows the serious effects amlodipine-atenolol overdose and the challenges of emergency patient management. An overdose of FDC of amlodipine and atenolol can cause cardiovascular collapse and severe metabolic acidosis. Timely and aggressive management with intravenous calcium infusion, HIE, and CVVHD is essential.

Efficacy of methylene blue in a murine model of amlodipine overdose

INTRODUCTION

Amlodipine overdoses have significant cardiac toxicity and are difficult to treat. Methylene blue has potential as a treatment for overdoses.

METHODS

A randomized controlled study of methylene blue as a treatment for amlodipine toxicity was conducted in C57Bl/6 mice. A baseline echocardiography was followed by gavage administration of amlodipine (90 mg/kg). Five minutes after gavage, animals received either vehicle solution (controls) or methylene blue (20 mg/kg) by intra-peritoneal injection. Animals were continuously monitored, and cardiac parameters were acquired every 15 min up to two hours.

RESULTS

Only 50% of control animals survived to the two-hour endpoint compared to 83% that received methylene blue. Amlodipine delivery induced significant reduction in left ventricular ejection fraction (EF), fractional shortening (FS), stroke volume (SV), and cardiac output (CO) in the vehicle treated animals relative to animals in the treatment group (p < 0.05 vehicle versus Methylene blue for EF, FS, SV, CO, and HR).

DISCUSSION

The amlodipine dose induced cardiotoxicity that were effects were more pronounced in the untreated group. 50% vehicle controls quickly progressed into heart failure (within 90 min of exposure) and did not survive the two h observation endpoint. Distinctly, only one animal from the Methylene blue treatment group did not survive (83% survival) the study. Additionally, the surviving animals from the Methylene blue group displayed significantly higher ejection fraction, fractional shortening, stroke volume, and cardiac output compared to vehicle group, indicating that methylene blue preserved cardiac function.

CONCLUSION

In this mouse model of amlodipine overdose, methylene blue decreased cardiac toxicity.

Lipid emulsion attenuates extrinsic apoptosis induced by amlodipine toxicity in rat cardiomyoblasts

Amlodipine-induced toxicity has detrimental effects on cardiac cells. The aim of this study was to examine the effect of lipid emulsion on decreased H9c2 rat cardiomyoblast viability induced by amlodipine toxicity. The effects of amlodipine, lipid emulsion, LY 294002, and glibenclamide, either alone or in combination, on cell viability and count, apoptosis, and expression of cleaved caspase-3 and -8, and Bax were examined. LY 294002 and glibenclamide partially reversed lipid emulsion-mediated attenuation of decreased cell viability and count induced by amlodipine. Amlodipine increased caspase-3 and -8 expression, but it did not alter Bax expression. LY 294002 and glibenclamide reversed lipid emulsion-mediated inhibition of cleaved caspase-3 and -8 expression induced by amlodipine. Lipid emulsion inhibited early and late apoptosis induced by amlodipine. LY 294002 and glibenclamide inhibited lipid emulsion-mediated inhibition of late apoptosis induced by amlodipine, but they did not significantly alter lipid emulsion-mediated inhibition of early apoptosis induced by amlodipine. Lipid emulsion decreased amlodipine-induced TUNEL-positive cells. These results suggest that lipid emulsion inhibits late apoptosis induced by amlodipine at toxic dose via the activation of phosphoinositide-3 kinase and ATP-sensitive potassium channels in the extrinsic apoptotic pathway.