S-MEPHENYTOIN, SPARTEINE AND DEBRISOQUINE OXIDATION - GENETIC POLYMORPHISMS IN A TURKISH POPULATION

A mephenytoin test was carried out in 106 unrelated healthy Turkish vo lunteers. Racemic mephenytoin was coadministered with either debrisoqu ine or sparteine. The S/R mephenytoin ratio ranged from < 0.1 to 0.73 in 105 subjects, accordingly phenotyped as extensive metabolisers. One subject had an S/R mephenytoin ratio of 1.02, showing that he was a p oor metaboliser of mephenytoin (0.94%, confidence interval 0.25% and 1 3.65%). In 48 subjects, the metabolic ratios of debrisoquine and spart eine were correlated significantly (r(s) = 0.61, P < 0.001).