Agranulocytosis in the course of phenothiazine therapy: case reports.

Agranulocytosis developed in three patients subsequent to chlorpromazine therapy and in one patient following treatment with methotrimeprazine and trifluoperazine. Although three of these four patients developed agranulocytosis within the expected time lapse (6 weeks), one patient developed the condition 12 years after the initiation of therapy. In one patient there was a recurrence of the agranulocytosis following reinstitution of chlorpromazine therapy. The subsequent treatment of psychosis is safer if another neuroleptic is substituted for the one that caused the agranulocytosis.