Table 5.

Antipsychotic dosing advice based on CYP2D6 phenotype according to DPWG (https://www.pharmgkb.org/gene/PA128/guidelineAnnotation/PA166104988) according to the recent large-scale study results (14).

	CYP2D6
	Poor metabolizer	Intermediate metabolizer	Normal metabolizer	Ultrarapid metabolizer
Aripiprazole	Reduce maximum dose by 33% (to 20 mg/day)	Reduce maximum dose by 33% (to 20 mg/day)	Recommended starting dose	Be alert for subtherapeutic drug levels (TDM) OR Select alternative drug
Risperidone	Reduce maximum dose by 33% (to 4 mg/day)	Reduce maximum dose by 33% (to 4 mg/day)	Recommended starting dose	Be alert for subtherapeutic drug levels (TDM) OR Select alternative drug
Haloperidol	Reduce the dose by 50% OR select alternative drug	Be alert to ADRs OR select alternative drug	Recommended starting dose	Be alert for subtherapeutic drug levels (TDM) OR Select alternative drug
Zuclopenthixol	Reduce the dose by 50% OR select alternative drug	Reduce the dose by 25% OR select alternative drug	Recommended starting dose	Be alert for subtherapeutic drug levels (TDM) OR Select alternative drug