[Fatalities caused by anticholinergic antiparkinsonian drugs. Analysis of findings in a 11-year national material].

All autopsy samples received at the National Institute of Forensic Toxicology during the years 1986-1996 which contained anticholinergic antiparkinsonian drugs were reviewed. Of a total of 69 cases, orphenadrine was present in 57 (83%), biperiden in 8 (12%), procyclidine in 3 (4%), and trihexyphenidyl/benzhexol in 1 (1%) of the subjects. The measured concentrations were assessed in light of previously published data. Of 21 cases where causality between drug ingestion and death was classified as either highly probable (18/21) or possible (3/21), all subjects tested positive for orphenadrine. In the autopsy samples from these patients, orphenadrine concentrations in the 4.5-600 mumol/l range (mean 62.5 mumol/l, SD 126.5 mumol/l) were determined. Because of a low national autopsy rate, there is reason to believe that the actual numbers of drug-related deaths in this period may have been significantly higher. It is concluded that orphenadrine is responsible for a disproportionally high number of overdose deaths.