Blood alcohol concentrations rise rapidly and dramatically after Roux-en-Y gastric bypass

Background: This study provides new information on how rapidly and extensively alcohol is absorbed after Roux-en-Y gastric bypass (RYGB). Previous alcohol pharmacokinetic research in RYGB patients has not reported blood alcohol concentrations in this early time period after ingestion. The objective of this study was to examine the rate and extent of alcohol absorption, particularly in the first 10 minutes after a dose of alcohol.

Methods: Five female participants who had undergone RYGB 3 to 4 years previously completed the study. Participants were given .3 g/kg of actual weight of ethanol. After the dose of alcohol, blood samples were collected through an indwelling intravenous catheter every minute for the first 5 minutes and at 7.5, 10, 20, and 60 minutes.

Results: The observed mean Cmax was 138.4±28.6 mg/dL (range 98.0-170.0 mg/dL), and the observed mean Tmax was 5.4±3.1 minutes (range 2-10 minutes) after alcohol consumption.

Conclusions: Within minutes after consumption of a beverage containing a modest amount of alcohol, post-RYGB patients achieve disproportionately high blood alcohol concentrations. All 5 participants in this study reached blood alcohol concentrations>.08%, the legal driving limit in the United States, within 10 minutes after a dose of alcohol. Clinicians are encouraged to educate patients about the marked changes in alcohol pharmacokinetics that are they are likely to experience after RYGB and to guide patients in making modifications to alcohol intake after surgery accordingly.