ACID REDUCING MEDICATIONS FOLLOWING BARIATRIC SURGERY: SEVEN YEAR FOLLOW-UP
•Acid reducing medications (ARM) are commonly used by bariatric surgery candidates due to the high prevalence of gastroesophageal reflux disease (GERD) in patients with severe obesity.
•The effect of bariatric surgery on GERD depends on the type of procedure. Studies have shown that GERD improves following Roux-en-Y Gastric Bypass surgery (RYGB), while, Sleeve Gastrectomy (SG) may increase the risk of GERD following surgery (Frezza et al 2002; Akkary et al 2008; Arman et al, 2016). Results regarding the effect of Laparoscopic Adjustable Gastric Banding (LAGB) on GERD are mixed (De Jong et al 2010; Suter et al 2005).
•The effect of bariatric surgery on the rate of long term ARM use is unknown. ARM use after surgery may not only be affected by changes in GERD status, but also by long-term gastrointestinal (GI) complications that may occur following bariatric surgery. The GI complications that may occur following RYGB include marginal ulcer (MU), anastomotic strictures, and gastrogastric fistulae.
•The aim of this study was to investigate the frequency of ARM use before and after bariatric surgery.
Participants were assessed before and after (at 6 months and yearly for 7 years) bariatric surgery as part of the Longitudinal Assessment of Bariatric Surgery-2 (LABS-2) study. LABS-2 is an observational cohort study, and 2,458 participants who underwent a first bariatric surgical procedure (most commonly RYGB or LAGB) as part of clinical care between 2006 and 2009 in one of 10 US hospitals were enrolled.
Medication use over the past 90 days was recorded for 2,398 patients on the LABS-2 Medication Use Form at each visit. Patients who underwent RYGB or LAGB were included in this study.
ARM use for this analysis required daily intake of one or more ARMs. ARMs were categorized into four groups based upon pharmacological class, including: 1) Proton Pump Inhibitors (PPIs), 2) H2 Antagonists, 3) Antacids and Sucralfate, and 4) ARM, type unspecified.
Generalized Estimating Equations was used with binomial assumptions for the repeated measures to study the changes in ARM use over time. Findings with significance levels of less than 0.01 were considered significant.
•Around 25% of patients who underwent RYGB or LAGB took one or more ARM daily at baseline.
•LAGB: At six months after LAGB, ARM use had decreased to 16% and remained significantly lower than baseline throughout all 7 years (p<0.005).
•RYGB: In contrast, following RYGB, there was no significant change in ARM use from baseline at any time-point.
•Among ARMs, PPIs were the most frequently used category prior to surgery for both LAGB (90.5%) and RYGB (87.9%). Although PPIs remained the most frequently used ARM following surgery, the ratio of PPI to H2 antagonist use decreased between baseline and six months following both LAGB and RYGB, suggesting a shift toward less PPI and more H2 antagonists post-surgically.
•Following LAGB, ARM use declined significantly up to 7 years following surgery. This finding is in accordance with a study by Varban et al., 2015, which found a significant decrease in ARM use 1 year following LAGB. Decrease in ARM use may be due to improvements in GERD symptoms associated following weight loss.
•Unlike LAGB, ARM use did not decline following RYGB. The high prevalence of ARM use following RYGB may indicate that post-RYGB patients take ARMs to prevent and/or treat GI complications following RYGB, including MU. MU is an important complication of RYGB and its incidence varies between 0.6% and 25% (Coblijn et al. 2014). Although the effectiveness of prophylactic therapy is not clear, 88% of surgeons reported their preference for prophylactic therapy, and 91% of them preferred PPI as the prophylactic method. PPI is also the first line treatment for MU following RYGB (Steinemann et al., 2014).
•A shift toward less use of PPIs and more use of H2 antagonists was observed following surgery which is somewhat unexpected given the over-the-counter availability of both classes of medications during the time period of data collection.
•Further research is needed to determine the reasons for differential long-term use of ARM by surgical procedure. Also, long-term ARM use following SG, the most commonly bariatric surgery performed in the US, needs to be investigated in future studies.