Prolonged severe hypotension following combined amlodipine and valsartan ingestion.
BACKGROUND
Compared to other calcium channel blockers (CCBs), overdose with dihydropyridine CCBs are considered relatively benign due to their vascular selectivity. Although not a sustained-release preparation, amlodipine's prolonged duration of effect is concerning following overdose. In addition, angiotensin II receptor blocker blunting of vasoconstrictive and sympathetic compensatory responses could exacerbate calcium channel blocker toxicity. We describe severe toxicity associated with an overdose of amlodipine and valsartan.


METHODS
A 75-year-old woman presented to the ED 45 minutes after a witnessed suicidal ingestion of a "handful" of amlodipine and valsartan tablets. Hypotension, which appeared two hours after ingestion, was refractory to crystalloids and colloids, calcium gluconate, epinephrine, norepinephrine, phenylephrine, and vasopressin infusions. High-dose insulin euglycemia (HIE) therapy, and treatment with glucagon and naloxone were successful in improving her hemodynamic status. In this combined overdose, right heart catheterization demonstrated both negative inotropic effects and decreased systemic vascular resistance.


CONCLUSIONS
Co-ingestion of amlodipine with valsartan produced profound toxicity. Early institution of HIE therapy may be beneficial to reverse these effects.
New York City Poison Control Center, New York, New York 10016, USA. smiths11@med.nyu.edu
Silas W
SW
Smith
Kathy L
KL
Ferguson
Robert S
RS
Hoffman
Lewis S
LS
Nelson
Howard A
HA
Greller
D000368:Aged; D017311:Amlodipine / Q000506:poisoning*; D000931:Antidotes / Q000627:therapeutic use; D000959:Antihypertensive Agents / Q000506:poisoning*; D001786:Blood Glucose / Q000032:analysis; D002121:Calcium Channel Blockers / Q000506:poisoning*; D006328:Cardiac Catheterization; D004347:Drug Interactions; D062787:Drug Overdose; D005260:Female; D005934:Glucagon / Q000627:therapeutic use; D006801:Humans; D007022:Hypotension / Q000139:chemically induced*; D007328:Insulin / Q000627:therapeutic use; D009270:Naloxone / Q000627:therapeutic use; D012720:Severity of Illness Index; D013406:Suicide, Attempted; D013777:Tetrazoles / Q000506:poisoning*; D013997:Time Factors; D014633:Valine / Q000031:analogs & derivatives* / Q000506:poisoning; D000068756:Valsartan
D000931:Antidotes; D000959:Antihypertensive Agents; D001786:Blood Glucose; D002121:Calcium Channel Blockers; D007328:Insulin; D013777:Tetrazoles; D017311:Amlodipine; D009270:Naloxone; D000068756:Valsartan; D005934:Glucagon; D014633:Valine