Dose Equivalents for Antipsychotic Drugs: The DDD Method: Table 1.

Dose equivalents of antipsychotics are an important but difficult to define concept, because all methods have weaknesses and strongholds.

We calculated dose equivalents based on defined daily doses (DDDs) presented by the World Health Organisation's Collaborative Center for Drug Statistics Methodology. Doses equivalent to 1mg olanzapine, 1mg risperidone, 1mg haloperidol, and 100mg chlorpromazine were presented and compared with the results of 3 other methods to define dose equivalence (the "minimum effective dose method," the "classical mean dose method," and an international consensus statement).