Atropine like effects

Atropine-like effects (dry mouth, constipation, urinary retention, and visual problems) are often pronounced with the use of thioridazine and phenothiazines with aliphatic side chains (eg, chlorpromazine). These effects also occur with clozapine and most of the atypical drugs but not with ziprasidone or aripiprazole. Postural hypotension caused by α blockade is a common manifestation of many of the older drugs, especially phenothiazines. In the elderly, measures must be taken to avoid falls resulting from postural fainting. The atypical drugs, especially clozapine and ziprasidone, also block α receptors and can cause orthostatic hypotension.