DRUGS INDUCING OR AGGRAVATING PARKINSONISM - A REVIEW

Drug-induced parkinsonism (DIP) is frequent. The list of drugs able to induce parkinsonism is long and probably incomplete, because new drug s, with previously unknown antidopaminergic activity, are constantly b eing added. Not all the drugs have the same potency for inducing parki nsonism. We classify these drugs in three groups: (1) drugs with obvio us antidopaminergic activity which regularly induce parkinsonism; (2) drugs able to induce parkinsonism in particular individuals and (3) dr ugs which may aggravate Parkinson's disease treated with levodopa. The reports of isolated cases of parkinsonism induced by widely-used drug s (drugs in group 2) may be the result of either an idiosyncratic side effect or a misdiagnosis of parkinsonism. The antidopaminergic activi ty of the drugs of this group is weak and not sufficiently demonstrate d. Maybe, in these cases, the blockage of other neurotransmitters diff erent from dopamine plays a role in the induction of parkinsonism. Pro bably, the number of patients with DIP is higher than reported or dete cted, because many patients suffer from weak symptoms that quickly dis appear after drug withdrawal. One of the main points of interest is kn owing the list, because all these drugs, specially those of group 1, s hould be avoided or used with caution in the treatment of some common symptomatic problems in patients with Parkinson's disease, such as dep ression, arterial hypertension, diabetes mellitus and cardiac disorder s. The precautions should extend to other populations especially susce ptible to suffer from DIP, such as the elderly or patients with other neurodegenerative disorders, such as Alzheimer's disease.