the compound carvedilol has the chemical formula : ñ - 1 -- 3 - ethyl ] amino ]- 2 - propanol . it exists in the form of optical isomers r - and s - carvedilol , and as mixtures of these isomers . it , or one of its optical isomers , is administered , preferably orally , several times per day in tablets of 3 - 25 mg for the treatment , prevention and clinical arrest of movement disorders associated with medications which block dopamine receptors , including many antipsychotic and antiemetic medications . such movement disorders include tardive dyskinesia , tardive dystonia , and tardive akathisia . the compound carvedilol is also administered to improve the treatment of mental disorders in which dopamine - blocking medications are used , such as manic episodes , major depressive episodes , and psychoses such as schizophrenia and schizoaffective disorder .