Alternate day levodopa therapy in parkinsonism.

Chronic high dose levodopa therapy in Parkinson disease is associated with an apparent loss of efficacy and an increased prevalence of side effects which limit is effectiveness. The use of minimum dosage has therefore been recommended. We found that los-dose alternate-day levodopa provided adequate control of early but not late parkinsonism. Stable clinical responses occurred both on the day of drug administration and on the following day, although plasma dopa levels were negligible on the day when the drug was not given. Alternate-day therapy results in less cumulative dosage and may better preserve existing compensatory striatal activity, leading to more effective long-term treatment.