Why is antipsychotic dose important?

Antipsychotic dose comparison is important both in clinical practice and for research purposes. The aim is to determine the lowest dose range that is sufficient to produce a satisfactory clinical response, while avoiding unnecessary side effects. Near-maximal effective dose is the highest dose range just before efficacy plateaus. Minimum effective dose is the lowest dose that is significantly more effective than placebo.

What is the evidence for antipsychotic dose?

Moderate quality evidence suggests a small to medium-sized effect of fewer relapses in patients receiving standard dose antipsychotics compared to patients receiving very low dose antipsychotics (< 50% of daily defined dose), although very low dose antipsychotics resulted in fewer people dropping out of trials due to side effects. No differences were reported in relapses or side effects when low dose (50 to < 100% of daily defined dose) was compared to standard dose. High quality evidence suggests a medium-sized effect of lower olanzapine concentration-to-dose ratio in smokers than in non-smokers with schizophrenia. Moderate to high quality evidence suggests intermittent therapy is less effective than maintenance therapy for reducing the risk of relapse. Moderate to low quality evidence suggests there are different minimum and near-maximal effective doses for individual antipsychotic medications (please see the technical table for individual dose information).

March 2019

Last updated at: 3:32 am, 1st April 2019
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