Combined Lithium and Electroconvulsive Therapy: Pharmacokinetic and Pharmacodynamic Interactions

The combined use of lithium and electroconvulsive therapy (ECT) is currently contraindicated, due to reports of associated neurotoxicity and poor outcome. Only limited data are available to explain any pharmacological basis for an adverse interaction between the two treatments. ECT does not alter lithium distribution or kinetics. Possible drug-drug interactions between lithium and ECT premedication have been subjected to little systematic study. Despite a body of preclinical work implicating the cholinergic system in the mechanism of action of both lithium and ECT, no interaction between lithium and pre-ECT anticholinergic medication has been reported. Potentiation of barbiturate anesthetics and neuromuscular blocking agents, including succinylcholine, by lithium has been noted in the anesthesiology literature, but reports of such interaction are lacking in the context of ECT administration. Thus, no demonstrable pharmacokinetic or drug-drug interaction factors preclude combined prescription of lithium and ECT.