Pharmacokinetics of aspirin: evaluating shortcomings in the literature

Abstract

Introduction: Aspirin is known for its therapeutic benefits in preventing strokes and relieving pain. However, it is toxic to some individuals, and the biological mechanisms causing toxicity are unknown. Limited literature is available on the role of glycine conjugation as the principal pathway in aspirin detoxification. Previous studies have quantified this two-step enzyme reaction as a singular enzymatic process. Consequently, the individual contributions of these enzymes to the kinetics remain unclear.

Areas covered: This review summarized the available information on the pharmacokinetics and detoxification of aspirin by the glycine conjugation pathway. Literature searches were conducted using Google Scholar and the academic journal databases accessible through the North-West University Library. Furthermore, the factors affecting interindividual variation in aspirin metabolism and what is known regarding aspirin toxicity were discussed.

Expert opinion: The greatest drawback in understanding the pharmacokinetics of aspirin is the limited information available on the substrate preference of the xenobiotic ligase (ACSM) responsible for activating salicylate to salicyl-CoA. Furthermore, previous pharmacokinetic studies did not consider the contribution of other substrates from the diet or genetic variants, to the detoxification rate of glycine conjugation. Impaired glycine conjugation might contribute to adverse health effects seen in Reye's syndrome and cancer.

Keywords: Aspirin; glycine N-acyltransferase; glycine conjugation; medium chain/xenobiotic fatty acid: CoA ligase; pharmacokinetics; toxicity.