The identification of patients as 'fast acetylators' or 'slow acetylators' is used in clinical practice to help recognize those at risk from toxicity and in guiding the dosage of N-acetylated drugs. Caffeine has been proposed as a marker for drug acetylation on the basis of a ratio of urinary metabolites (5-acetylamino-6-formylamino-3-methyl uracil and 1-methylxanthine, AFMU:MX) determined by high-performance liquid chromatography. The caffeine test was studied in 26 subjects by reference to the use of sulphamidine as the test substance. The distribution of urinary AFMU:MX ratios allowed assignment of subjects to 'slow' and 'fast' acetylator status (AFMU:MX < 2.1 and > 2.3 respectively). The results showed accordance with those from the sulphadimidine test with the exception of one subject. The possible interference of concurrent administration of sulphadimidine (as an example of a drug known to undergo metabolism by N-acetylation) was also studied in 11 of the subjects. The interference was found to be small (apparent mean bias 11%) but of possible clinical significance.
|Number of pages||5|
|Journal||Journal of Clinical Pharmacy and Therapeutics|
|Publication status||Published - 1987|