Non-cardiogenic pulmonary edema and life-threatening shock due to calcium channel blocker overdose: A case report and clinical review

Calcium channel blockers (CCBs) overdose can be life-threatening when manifest as catastrophic shock and non-cardiogenic pulmonary edema. We describe a case of massive overdose of multiple medications, including sustained-release verapamil, which was resistant to conventional support. Initial treatment for CCB overdose is primarily supportive, and includes fluid resuscitation. The mechanism of non-cardiogenic pulmonary edema is not well known, and reported cases have been successfully treated with mechanical ventilation. Circulatory shock may fail to respond to atropine, glucagon, and calcium in severely poisoned patients, and vasopressors are usually required. Attempting to overcome calcium-channel antagonism with the supra-therapeutic doses of calcium salts is clinically indicated to reverse hypotension and bradycardia. There is evidence that hyperinsulinemia-euglycemia therapy is superior to other therapies for CCB poisoning, and the mechanism is thought to be the insulin-mediated active transport of glucose into the cells, which counters the CCB-induced intra-cellular carbohydrate-deficient state. Conventional decontamination measures are ineffective in accelerating clearance of CCB. Experience with intravenous lipid emulsion for lipophilic drug overdose, such as verapamil, is limited, but has been proposed as a rescue therapy and might improve cardiac inotropy through intravascular sequestration of the lipophilic CCB.