Low-dose treatment strategies.

Dose-comparison studies in chronic, continuously hospitalized patients show that megadoses of antipsychotic drugs are reasonably well tolerated. These findings, together with dose-comparison studies in acute patients, support the notion (and current practice) that the therapeutic index of antipsychotic drugs is wide. Recent work with outpatients indicates that fluphenazine decanoate 5 mg (versus 25 mg) every 2 weeks is effective for at least the first year. In addition, patients report feeling better when they take the lower dose. A dose-comparison study with haloperidol in newly admitted patients indicates that a 20 mg daily dose has neurotoxic effects. A similar dose-comparison study with oral fluphenazine indicates that a 5 mg daily dose is efficacious over a 3-week period. Thus, both inpatients and outpatients can be managed on doses that were formerly regarded as homeopathic. Patients taking low doses have fewer side effects (particularly less akinesia) and probably fewer dysphoric emotions than patients taking high doses, although they improve at a slower rate.