Dissimilar dosing with high-potency and low-potency neuroleptics

The authors studied high-potency versus low-potency neuroleptic dosing practices for 110 Boston-area psychiatric inpatients and compared the findings with the dosing practices reported in surveys of nearly 16,000 Veterans Administration patients. Mean chlorpromazine equivalent doses for the most common agents correlated strongly in both samples. Although frequencies of lower doses of both types of agents were similar, doses of potent drugs above the daily equivalent of 1 g of chlorpromazine accounted for more than 40% of prescriptions. The mean chlorpromazine-equivalent dose of popular potent agents (haloperidol or fluphenazine) was 3.54 times as high as that of popular low-potency agents (chlorpromazine or thioridazine). Potent agents are commonly used in mania and schizophrenia, often in relatively high doses, which may carry an excess of risk over unproven added benefit.