An evaluation of papaverine in tardive dyskinesia.

An evaluation of papaverine was carried out in nine hospitalized chronic patients with moderate to servere tardive dyskinesia. Changes in movements were assessed on the Simpson and AIMS scales by two trained rates blind to the study design. Results showed a modest 20-25 per cent improvement in oral dyskinesia, but only two of the nine patients showed clinically obvious improvements in their movement disorders. No drug-induced side effects were found. The mechanism of pharmacologic action of papaverine in movement disorders needs to be clarified, but dopamine receptor blockade may be primarily involved.