An 18-year-old male who abused several over-the-counter (OTC) drugs, mainly diphenhydramine, was admitted to the emergency department. He presented with tachycardia, delirium, tremor, and tonic convulsions. He was treated with diazepam, tracheal intubation, and activated charcoal. His symptoms appeared to be caused by diphenhydramine poisoning. In addition, we suspected that the combined use of diphenhydramine, alcohol, and an anticholinergic agent exacerbated the poisoning symptoms. His symptoms improved with time and he was discharged on day 6.
In recent years, the routes for obtaining drugs and information are becoming more diverse. While OTC drugs are often readily available, we need to be aware that certain types of medication can cause serious symptoms.