Massive eosinophilic reaction to desipramine in conjunction with pneumonia

The authors report on a female patient with bipolar affective disorder who presented with marked eosinophilia in conjunction with pneumonia five days after a medication change from amitriptyline to desipramine (for intolerable dry mouth). She improved with discontinuance of medications and supportive management, and her eosinophilia normalized. Reinstitution of desipramine was followed by prompt appearance of asymptomatic eosinophilia, which resolved with discontinuation of desipramine. A subsequent depression managed with amitriptyline was followed by no abnormal white blood count findings. Eosinophilia is occasionally encountered in imipramine or desipramine therapy and, although usually asymptomatic, appears to be manageable by switching to amitriptyline or nortriptyline.