Identification of Omeprazole Metabolites in Human Urines and Investigation of Its Pharmacokinetic Variability

Basis Independent Silicon Valley, Santa Clara, California, United States

^* Corresponding author: alanzhong2006@gmail.com

Abstract

Omeprazole is a commonly prescribed drug used to treat gastroesophageal reflux diseases (e.g., heartburn). Metabolism is the chemical alteration of foods or drugs by the body’s natural processes, and metabolites are the substances resulting from this metabolism. Drug metabolite identification is a means of profiling new chemical entities formed from the drug metabolism process. Although most metabolites are considered safe, some metabolites are associated with drug-induced toxicities. Legacy drugs such as omeprazole have not been thoroughly studied as many metabolites remain unknown. In this study, urine samples were used to reveal eight unknown metabolites and structures were tentatively proposed based on ultra-high performance liquid chromatography-mass spectrometry (UPLC-HRMS). Metabolites are not the only concern drugs pose as different drugs have varying interactions with the body based on the patient unique characteristics. Individualized medicine is the concept that different patients should have different dosing regimens as several factors may affect a patient’s reaction to a drug, including age, organ function, and concurrent use of other medications. The pharmacokinetic parameters investigated in this study can provide evidence for the importance of individualized medicine which emphasizes that one dose does not fit all people. The different groups that were studied include: young healthy patients, elderly patients, renally impaired patients, and patients that were co-administered with other drugs. For instance, the clearance of renally-impaired patients was significantly decreased compared to other groups as they do not have complete renal function. The group on the other concurrent medication demonstrated drug-drug interactions of omeprazole with armodafinil, osilodrostat, and ritonavir.