The effects of intravenous lipid emulsion on prolongation of survival in a rat model of calcium channel blocker toxicity.

CONTEXT: Intravenous lipid emulsion (ILE) has been shown to ameliorate the toxicity of lipid-soluble agents in animal studies and clinical cases.

OBJECTIVES

To investigate the therapeutic effects of ILE in a rat model of toxicity from calcium channel blockers (CCBs), including diltiazem and nicardipine.

METHODS

Two sets of experiments of CCB poisoning were conducted. In the first set, 14 male Sprague-Dawley rats were sedated and treated with ILE or normal saline (NS), followed by continuous intravenous infusion of diltiazem (20 mg/kg/h). In the second experiment, the study protocol was the same except the infusion of nicardipine (20 mg/kg/h). The total dose of infused drug and the duration of survival were measured. In addition, mean arterial pressure and heart rate were monitored.

RESULTS

Survival was prolonged in the ILE group (48.4 ± 11.3 vs. 25.0 ± 3.7 min; p = 0.002). Furthermore, the cumulative mean lethal dose of diltiazem was higher in the ILE group (16.1 ± 3.8 mg/kg) than in the NS group (8.3 ± 1.1 mg/kg) (p = 0.002). With nicardipine poisoning, survival was also prolonged in the ILE group (71.0 ± 8.3 min vs. 30.6 ± 6.1 min; p = 0.002). The cumulative mean lethal dose was higher in the ILE group than in the NS group (23.7 ± 2.8 mg/kg vs. 10.2 ± 2.0 mg/kg; p = 0.002).

CONCLUSIONS

ILE pretreatment prolonged survival and increased the lethal dose in a rat model of CCB poisoning using diltiazem and nicardipine.