Introduction: Intravenous fat emulsion (IFE) and high dose insulin (HDI) have been reported in treatment of overdoses, although rarely in combination. We report a life-threatening overdose of diltiazem, metoprolol and amiodarone, successfully treated with IFE and HDI.
Case report: A 30-year-old woman presented to the ED for abdominal pain. Medical history included hypertrophic cardiomyopathy (HCM) with CHF and an AICD. Initial vital signs were BP 89/46 and HR 73. Over 3 h the BP and HR dropped to 64/41 and 70, respectively, and she became confused. ECG showed a paced rhythm. Normal saline (NS) was given (2 L IV) during a negative workup for her pain. She then admitted to taking all of her diltiazem, metoprolol, and amiodarone 6 h prior to arrival, and that she never had abdominal pain. She was given another 2 L NS, 27 mEq IV Ca2+, and an HDI bolus of 0.5 U/kg with an HDI infusion escalated over an hour to 10 U/kg/h. She remained hypotensive, confused, and anuric. The CVP was 20 and an Echo showed low EF. IFE (20%) was given as a 100 mL bolus and an infusion of 1.5 L over 1 h. Within 15 min of the bolus the BP was 110/60 and confusion improved. After 5 days she went from the ICU to psychiatry with no sequelae. Serum levels from the ED were diltiazem: 1,449 ng/mL (nl 130–190), metoprolol: 388 ng/mL (30–300), and amiodarone: 2.7 mg/L (0.5–2).
Discussion: Reports of combined IFE/ HDI use are rare, as are reports of IFE use in awake patients. Further, IFE use with these specific overdoses has not been reported. HDI may have been ineffective in the setting of HCM as the inotropic and vasodilatory mechanisms of HDI may have been counter-productive. IFE was associated with rapid improvement. A drug’s log P octanol/water partition coefficient may correlate with the effectiveness of IFE. The log P for diltiazem, metoprolol, and amiodarone are 2.7, 1.88, and 7.8, respectively. These are similar to log P for drugs reportedly treated effectively with IFE.
Conclusion : This is the initial report of the use of IFE for diltiazem, metoprolol, or amiodarone overdose and represents an addition to the rare reports of the combination of IFE/HDI therapy. This combination was successful for this patient in reversing severe drug-induced cardiogenic shock.