title: How much is too much? Oligosymptomatic presentation after 11.5 g of diphenhydramine.
abstract: We report the case of a 47-year-old male obese Caucasian patient presenting 2 hours after ingestion of 11.5 g of diphenhydramine. Despite this excessive overdose, he showed only a few hours of impaired consciousness and no further symptoms. A diphenhydramine plasma concentration of 15,352 nmol/L was measured 8 hours after the overdose ingestion. A heterogeneous CYP2D6 extensive metabolizer genotype excludes a pharmacokinetic explanation for this unusually oligosymptomatic presentation. However, the patient suffered from longstanding, refractory depression despite numerous treatment attempts with various drugs, pointing to the possibility of decreased pharmacodynamic responsiveness for therapeutic and toxic effects.
authors: Department of Internal Medicine, Stadtspital Triemli, Zurich, Switzerland. sonia.frick@triemli.stzh.ch
authors: Sonia
authors: S
authors: Frick
authors: Markus
authors: M
authors: Roos
authors: Karin
authors: K
authors: Fattinger
mesh_terms: D018926:Anti-Allergic Agents / Q000097:blood / Q000493:pharmacokinetics / Q000506:poisoning; D004155:Diphenhydramine / Q000097:blood / Q000493:pharmacokinetics / Q000506:poisoning*; D004305:Dose-Response Relationship, Drug; D062787:Drug Overdose; D006634:Histamine H1 Antagonists / Q000097:blood / Q000493:pharmacokinetics / Q000506:poisoning; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D018926:Anti-Allergic Agents; D006634:Histamine H1 Antagonists; D004155:Diphenhydramine