Joelle Abi Azar, Marcel Bassil, Jihad Irani, Karine Al Badawi, Carla Sawan, Moussa Moussa, Noha Hakimeh and Edmond Abboud
Background: Diabetes Mellitus (DM) is a chronic medical condition characterized by high levels of blood glucose due to a dysfunction in the amount or the function of the hormone insulin. Among the oral hypoglycaemic 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 gender, age, other medications, lifestyle differences, creatinine levels, etc.
Methods: A cross sectional study was conducted 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, such as gender, weight, other medications (drug-drug interaction), Kidney function (measured by creatinine level and eGFR), timing of metformin intake, dosage, duration since metformin intake, HBA1C, smoking and alcohol intake. The HPLC technique was used to detect the levels of metformin in 95 samples, collected from diabetic patients visiting the Saint Georges Hospital laboratory in Beirut.
Results: No correlation was found between the levels of metformin in blood or urine and the following variables: age, creatinine, GFR, years on metformin, HbA1c level, glucose level, and gender. Two linear correlations were obtained from the study; daily dose of metformin vs. urine (Spearman r=0.6 and p<0.001); and daily dose of metformin vs. weight (p=0.044).
Conclusion: The drug is administered and totally excreted from the body. The correlation “dose-metformin concentration in urine” could be used as a clinical purpose to check patient compliance to the treatment.