The impact of the <i>CYP2D6</i> polymorphism on haloperidol pharmacokinetics and on the outcome of haloperidol treatment

Abstract

Treatment with haloperidol should be avoided in extremely slow and extremely rapid metabolizers of CYP2D6 substrates. Both genotyping and blood concentration measurement explained only a fraction of the adverse events; about 20 patients would have to be genotyped to achieve a significant benefit in 1 patient. It is interesting that genotyping was at least as good a predictor of adverse events as the measured drug concentrations.