Comparative Doses and Costs of Antipsychotic Medication

TLDR

Clinicians benefit from a reference table that expresses neuroleptic doses in chlorpromazine equivalents. The study seeks to generate such a table by analyzing double‑blind controlled trials of flexible neuroleptic dosing in schizophrenia. Neuroleptics were converted to 100‑mg chlorpromazine equivalents, compared with expert‑derived tables, and used to compute cost comparisons. The analysis shows that absolute cost differences are modest, yet prescribing the largest available capsule or tablet for a given dose can produce significant savings.

Abstract

• It is clinically useful to have a table listing the equivalent doses of the various neuroleptics to a standard, such as chlorpromazine. This article derives such data by reviewing doubleblind controlled studies that used a flexible dosage schedule of neuroleptics in treating schizophrenic patients. Each neuroleptic is then converted to 100-mg chlorpromazine equivalents. This empirically derived dosage comparability table is compared with a similar table derived from the opinions of experts. Since these comparable doses produce equivalent amounts of antipsychotic activity, the cost to provide such medication was then calculated, and a table comparing the costs of the different neuroleptics was constructed. In absolute amounts, the cost differences between drugs are small. However, for any drug, large savings accrue when the largest possible capsule or tablet to achieve the desired dose is prescribed.