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

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.