To the Editor.—
Duvoisin and Katz (206:1963-1965, 1968) indicated that the anticholinergic drugs, including scopolamine, atropine, and various antiparkinsonian agents, can cause a toxic confusional state, and that physostigmine, a compound which antagonizes anticholinergic effects, is effective in reversing this "central anticholinergic syndrome." Certain patients experience a worsening of psychotic symptoms on high doses of phenothiazines given in combination with antiparkinsonian agents or tricyclic antidepressants. All of these medications theoretically possess anticholinergic properties, so that additive anticholinergic activity might be expected to occur, producing what is essentially an atropine psychosis. This report describes three female schizophrenic patients who had episodes of clinical worsening after receiving a combination of psychotropic and antiparkinsonian agents, and whose symptoms reversed with physostigmine administration.The first patient received daily doses of benztropine mesylate, 12 mg; perphenazine, 72 mg; and imipramine, 150 mg; the second patient received benztropine mesylate, 6.0 mg; and thioridazine, 150 mg,