High dosage haloperidol in chronic schizophrenia.

In a double blind chlorpromazine-controlled trial, high dosage haloperidol (100 mg daily) given for three months, appreciably improved the mental state of male chronic 'drug resistant' schizophrenic inpatients in the rehabilitation/long-stay unit of one psychiatric hospital. The results of a three-month follow-up suggested that the improvement could be maintained in some patients on lower doses of the drug. Serious extrapyramidal side effects were not seen at high doses. However, the majority of patients on haloperidol showed a deterioration in ward behaviour, possibly related to drowsiness, and developed raised serum alkaline phosphatase levels. These side effects disappeared in the follow-up period when either the drug was discontinued or the dose of haloperidol reduced.