Abstract

Tardive dyskinesia can be suppressed by dopaminergic receptor blockers, but often at the cost of a reciprocal increase in Parkinsonism. Oxiperomide, a dopaminergic antagonist that has been shown to reduce levodopa-induced dyskinesias without producing an equal aggravation of Parkinsonism, was evaluated in a blind placebo-controlled trial in 10 patients with tardive dyskinesia. It decreased tardive dyskinesia significantly (p less than 0.01) without significantly provoking or increasing Parkinsonism. There was no relationship between either tardive dyskinesia or Parkinsonism and eye blinking rates. These results can be interpreted as additional evidence for the existence of more than one population of dopamine receptors involved in controlling extrapyramidal function. Although oxiperomide is only a palliative suppressing agent in tardive dyskinesia, as the symptoms returned when the drug was stopped, it is an interesting agent in the search for selective dopaminergic receptor blockers.