1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP): one designer drug and serendipity

Through an unlikely series of coincidences and fortunate accidents, the development of Parkinson's disease in several illicit drug users was traced to their use of a meperidine analog contaminated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The discovery of a chemical capable of producing animal models of the disease has revitalized research efforts and resulted in important new information. The serendipitous finding also prompted consideration of what changes seem advisable if designer drugs are to be dealt with more efficaciously.