Effect of Gastric Bypass on the Absorption of Metformin

Overview

Background: Gastric bypass is the most commonly performed type of bariatric (obesity) surgery, has dramatically increased in popularity and is now considered to be preferred treatments in severely obese patients that fail non-surgical therapy - particularly in patients with type 2 diabetes. Drug malabsorption is a potential concern post-gastric bypass because intestinal length is reduced. Purpose: The purpose of this controlled, pharmacokinetic study is to determine whether the absorption of a single dose of metformin, the first line drug treatment in patients with type 2 diabetes, is significantly reduced after gastric bypass. Methods: A single dose of standard release metformin 1000 mg will be administered to patients who have undergone gastric bypass and to patients who have not received surgery but are on the wait list (wait-listed controls). Blood sampling and urine sampling will occur in standardized fashion over the ensuing 24 hours to measure and compare the absorption of metformin between study arms. 34 patients total will be recruited. Significance: Following completion of this study, we will better understand how gastric bypass affects metformin absorption. Ultimately, this information will help to ensure that this patient population is receiving optimal doses of this important drug treatment.

Conditions

Eligibility