AMLODIPINE OVERDOSE

OBJECTIVE: To report a nonfatal intentional overdose of amlodipine. CA SE SUMMARY: A 42-year-old woman with a history of hypertension reporte d ingesting 50-100 mg amlodipine besylate and at least 40 ounces of be er in a suicide attempt. The patient's symptoms were mild; BP ranged f rom 79/50 to 113/76 mm Hg and HR from 92 to 129 beats/min (sinus tachy cardia). Laboratory studies revealed normoglycemia, mild metabolic aci dosis, mild hypocalcemia, blood ethanol concentration of 263 mmol/L, a nd a serum amlodipine concentration of 88 ng/mL (normal 3-11) 2.5 hour s after ingestion. Therapy included activated charcoal, whole bowel ir rigation, and intravenous NaCl 0.9%. After receiving 1.5 L of NaCl 0.9 %, the patient developed signs of mild pulmonary edema that resolved o ver several hours without intervention. A serum amlodipine concentrati on obtained 35 hours later was 79 ng/mL. The patient was discharged on day 2 in good condition. DISCUSSION: In this case, an amlodipine over dose was associated with sustained hypotension and sinus tachycardia, as well as transient pulmonary edema following relatively low-volume f luid replacement. A previously published report described an amlodipin e overdose that was fatal due to refractory hypotension and was compli cated by concomitant oxazepam overdose. CONCLUSIONS: Amlodipine overdo se produces prolonged hemodynamic effects and may lead to pulmonary ed ema. Due to a long elimination half-life and delayed onset of effects, patients with amlodipine overdose should receive aggressive decontami nation therapy and may require extended clinical monitoring and suppor tive care if they are hemodynamically unstable.