Centrally-acting dopamine antagonists (such as the antipsychotics, including
prochlorperazine used at an antiemetic dose) may antagonise the effects of
levodopa. However, note that
clozapine may be used to reduce the
symptoms of neuropsychia- tric complications of Parkinson's disease. Additive hypotensive effects possible, see
antihypertensives.
Concurrent use should be avoided, or monitored closely, to ensure
levodopa remains effective.