To determine the prevalence, clinical signs and course of
drug-induced
Parkinsonism (DIP) in a general neurology practice, as well as to study the changing pattern of drugs implicated. Retrospective study of DIP patients seen between January 1981 and December 1993. Of the 306 cases of
parkinsonism seen, 56.8% were induced or aggravated by drugs. This side effects is more frequent in women and often occurs in old age. The drugs implicated most often were
cinnarizine,
sulpiride and
flupentixol. Forty-two patients took 2 drugs simultaneously, whereas 6 took 3. The number of DIP seen increased after 1986 and then remained stable through 1993. Between 1981 and 1988, the
drug most often implicated was
cinnarizine, though its relative impact decreased in later years. The most frequently seen form of presentation was rigidakinetic syndrome. Neither
drug nor age influenced clinical presentation.
Parkinsonism disappeared completely within a mean of 5 months in 142 (82%) patients. Twenty-eight (16%) developed
Parkinson's disease. Six of them were symptom-free for 12 to 72 months (mean 40 months), whereas 22 never experienced relief from
parkinsonism. Sixteen suffered
tardive dyskinesia, a complication that was not associated with the use of any particular
drug. More than half of the cases of
parkinsonism seen in a neurology practice are
drug induced or aggravated, generally by
psychotropic drugs. The frequency has held steady for the past 6 years. The drugs implicated change as knowledge of their inducement of
parkinsonism becomes known. The clinical picture is usually reversible.