EVIDENCE FOR THE POLYMORPHIC OXIDATION OF DEBRISOQUINE AND PROGUANIL IN A NEW-ZEALAND MAORI POPULATION

The genetic oxidation polymorphisms of debrisoquine and proguanil were studied in a New Zealand Maori population. A bimodal distribution was observed in the 0-4 h urinary debrisoquine/4-hydroxydebrisoquine meta bolic ratio. Of 101 Maori subjects phenotyped, five subjects (5%) were identified as poor metabolizers of debrisoquine, according to criteri a established in studies of Caucasian populations. The prevalence of t he debrisoquine poor metabolizer phenotype in the Maori appears to be similar to that reported for the Caucasian populations, but higher tha n that found in Asian (non-Caucasian) populations. The distribution of proguanil:cycloguanil (PG:CG) ratios obtained from 43 Maori subjects was highly skewed. Using a PG:CG ratio of 10 as the cut-off point, thr ee Maori subjects (7%) were classified as poor metabolizers of proguan il. The incidence of the poor metabolizer phenotype of proguanil oxida tion of 7% seems to be higher in Maori compared with Caucasian populat ions, but this is lower than the usual ranges (15-35%) reported in Asi an populations.