Risk of abuse of diphenhydramine in children and adolescents with chronic illnesses.

Diphenhydramine is generally considered an innocuous drug with a minimal risk for abuse and untoward side effects. We describe children and adolescents with chronic hematologic and oncologic diseases who exhibited drug-seeking behavior or anticholinergic symptoms with the use of diphenhydramine. These cases illustrate that the assumption that this drugs is without significant adverse effects may be unwarranted, especially for children and adolescents with chronic diseases.