262. A pharmacokinetic assessment of aspirin through timed analysis of plasma salicylate acid level: An analysis of difference in gender, dose and preparation of aspirin

Abstract

Introduction The benefit of aspirin in preventing preeclampsia is well established. Recent data, however, suggest variability in outcomes with its use. Two potential contributing factors are the dose and preparation of aspirin. Objective/hypothesis To determine the: pharmacokinetics of 100 mg coated (Coated100) vs 100 mg non-coated (NonCoated100) vs 150 mg non-coated (NonCoated150) aspirin. Pharmacokinetics of the above in male vs non-pregnant vs gestation-matched pregnant female subjects. Methods Three subjects from each group were given Coated100, NonCoated100 or NonCoated150 aspirin at different times. Blood samples were collected pre-ingestion, 1-h post, 2-h post, 4-h post, 6-h post, 12-h post and 24-h post-ingestion of aspirin. Samples were analysed for plasma salicylate acid (SA) utilising a validated liquid chromatography mass-spectrometry (LCMS) methodology. The differences in the area under the curves (AUC) were analysed using Kruskal-Wallis and Mann-Whitney-U (SPSS). Results The AUCs of Coated100, NonCoated100 and NonCoated150 were different across all three groups of subjects (p Discussion The pharmacokinetics of aspirin between male, non-pregnant and pregnant female differs, with lower AUCs in pregnant females. There is no difference in the dose-matched AUCs between coated and non-coated aspirin but a difference was noted in AUCs between preparation-matched 100 mg and 150 mg of Aspirin. The clinical significance of this in the high-risk pregnant women is yet to be examined, however, potentially supports the need for a higher dose of aspirin in pregnant women.