IS MG++ -DEFICIENCY ASSOCIATED WITH AN ANTIPSYCHOTICS-INDUCED QTC-PROLONGATION?

Abstract

Author(s): Dipl.-Psych. Dr. phil. Dr. med. Helmut Niederhofer

Atypical antipsychotics have been reported to prolong the QTc interval. Mg++ deficiency may also be a cause for QTc prolongation. For that reason it can be assumed that atypical antipsychotics may cause Mg++ deficiency and that Mg++ supplementation might compensate the QTc prolongation, caused by atypical antipsychotics. We compared Mg ++ levels of 40 patients, 20 of which received atypical antipsychotics and 20 of which didn`t. Furthermore, we checked the effect of Mg++ supplementation on the prolonged QTc interval in patients, who received atypical antipsychotics. The data of this study show, that atypical antipsychotics decrease serum Mg++ level (p = 0.001) and are also associated with a QTc prolongation (p = 0.069) and that Mg++ supplementation abbreviates an atypical AP-induced QTc prolongation. In patients who show a QTc prolongation while receiving atypical antipsychotics, Mg++ serum levels should be checked and, if lowered, Mg++ should be supplemented before ceasing antipsychotic medication.