Mixed fluoxetine/loxapine overdose and atrial flutter.

A 19-year-old man who attempted suicide by ingesting approximately 600 mg fluoxetine (Prozac) and 140 mg loxapine (Loxitane) had two episodes of atrial flutter shortly thereafter. Admission serum fluoxetine, norfluoxetine, and loxapine levels were 1,053 ng/mL, 702 ng/mL, and 40 ng/mL, respectively. This case of atrial flutter in association with an overdose of either of these drugs demonstrates the potential for cardiotoxicity with these agents in the overdose setting. Theoretical mechanisms of cardiotoxicity are presented.