The concept of antipsychotic dose equivalents is regarded as important and difficult to define. Previous methods and approaches highlighted the fact that a gold standard equivalency did not exist. Three reasons to pursue the development of a gold standard equivalency is to: 1) inform clinical decision-making when switches between antipsychotic agents is necessary; 2) assist in development of treatment guidelines; and 3) inform more accurate comparisons between antipsychotic medications.
The major strength of this method to define dose response is that DDDs are available for most drugs, including old antipsychotics, that they are based on a variety of sources, and that DDDs are an internationally accepted measure. Although the DDDs were not developed for dose equivalences, this summary can be a useful resource for pharmacovigilance studies.
The sections below are summarized from referenced article “Dose equivalents for antipsychotic drugs: the DDD method” published in Schizophrenia Bulletin (2016)
Defined Daily Doses (DDDs):
Limitations of use:
Leucht, S., Samara, M., Heres, S., & Davis, J. M. (2016). Dose equivalents for antipsychotic drugs: the DDD method. Schizophrenia bulletin, 42(suppl_1), S90-S94.