Hospital use of antipsychotic agents in 1989 and 1993: stable dosing with decreased length of stay

Abstract

Objective: This study evaluated recent and current use of antipsychotics by psychiatric inpatients.

Method: Computer-based hospital pharmacy records identified prescriptions for antipsychotics in 1993. Medical records were reviewed to verify prescription and clinical data, and these were compared with similar data from 1989.

Results: In 1993, antipsychotics were prescribed for 299 (42%) of 709 hospitalized patients. Treatment usually started within 24 hours of admissions averaging 18 days. High-potency agents were used 2.4 times more frequently than low-potency drugs; 13% received clozapine. The mean chlorpromazine-equivalent daily dose, corrected for as-needed supplements, was 305 mg; peak doses were 32% higher. Doses of the most potent agents (fluphenazine and haloperidol) were only 22%-33% above the overall mean. Rarely were two neuroleptics given simultaneously, but cotreatment with an anticonvulsant (84% of patients, 92% of whom received valproate), a potent benzodiazepine (81%), lithium (70%), one CNS depressant (84%), or more (45%) was common. Doses averaged 20% higher for men, 42% lower at age > 50 years versus 20-30 years, and 53% greater for schizophrenia or schizoaffective disorder versus other conditions. Comparison with 1989 admissions (N = 50) averaging 73 days indicated few differences in use of neuroleptics or benzodiazepines but less frequent use of anticonvulsants and lithium.

Conclusions: High-potency antipsychotic agents and clozapine were used most often in 1993; doses of high-potency agents were only slightly higher than doses of low-potency agents, but combinations with mood stabilizers were more common in 1993, when length of stay was one-fourth that in 1989.