HYDROXYLATION POLYMORPHISM OF DEBRISOQUINE HYDROXYLASE (CYP2D6) IN PATIENTS WITH SCHIZOPHRENIA IN NORWAY AND DENMARK

The isozyme debrisoquine hydroxylase (CYP2D6) is central for the elimi nation of neuroleptic drugs. The capacity to hydroxylate debrisoquine is currently examined by genotyping of the isozyme. Approximately 7% o f Europeans have a reduced capacity to hydroxylate debrisoquine, and t hey are defined as poor metabolizers. Two studies of small samples of well-defined patients with schizophrenia have shown that 6.5-6.6% were poor metabolizers, which is close to the rate in psychic normals. We found a total rate of 3.9% of poor metabolizers in a big sample (N = 5 09) of patients with schizophrenia. The rate in the Danish subsample ( N = 221) was 4.5%, and in the Norwegian sub-sample (N = 288) the rate was 3.5%. Our results indicate that the true rate of poor metabolizers among patient's with schizophrenia is still to be determined. (C) 199 8 John Wiley & Sons, Ltd.