Summary

The authors report the case of a 20-year-old man who presented with a de novo episode of hypomania subsequent to the initiation of quinacrine for treatment resistant giardiasis. The hypomanic episode commenced some 20 days after the successful completion of a week long course of quinacrine 100 mg three times daily. The hypomanic episode was treated with olanzapine 10 mg daily. Two months subsequent to this, the patient developed a moderate depressive episode which was treated with escitalopram and olanzapine. One month after the resolution of the depressive episode, he once again presented with a hypomanic episode. The recurring episodes of discrete mood disturbance all occurred within 5 months of the commencement of quinacrine in an individual with no personal history of affective disorders.