Factors determining the blood and urine concentrations of metformin among patients with type 2 diabetes

Abstract

Diabetes Mellitus (DM) is a chronic medical condition characterized by high level of blood glucose due to a dysfunction in the amount or the function of the hormone insulin. Among the oral hypoglycemic drugs used to treat DM, metformin is considered the first line treatment and is available in the Lebanese market in both its regular and extended release formulations. Metformin is prescribed at standard doses for all diabetic patients without taking into account variables such as age,sex, weight, medications (drug-drug interaction), kidney function,timing of metformin intake, dosage, duration since metformin intake and HBA1C.In this study, we aim to find the association between the ingested dose of metformin (extended release formulation) and its concentration in the blood and urine, and investigate the different factors that affect this relation. A cross sectional study was conducted to evaluate this association by collecting blood and urine samples from diabetic patients approaching the Saint Georges Hospital Laboratory in Beirut. Results showed two main correlations: Metformin concentration in urine versus dose frequency and the second one is metformin concentration in plasma versus weight. All other variables do not have any effect on metformin concentration in blood and urine and do not affect metformin activity or mode of action. The major findings could help in checking patients compliance to the treatment by detecting the level of metformin in urine. In addition, this study could be a starting point to develop personalized medicine.