Use of phentermine-topiramate extended release in combination with sleeve gastrectomy in patients with BMI 50 kg/m2 or more

Abstract

Background: Super obesity (body mass index [BMI] ≥50 kg/m²) treatment can be complicated and high risk.

Objectives: We studied whether the pre and postoperative use of phentermine and topiramate (phen/top) combined with laparoscopic sleeve gastrectomy (LSG) in super obesity increases the odds of achieving a BMI <40 at 2 years postoperatively.

Setting: Academic medical center in Winston Salem, North Carolina.

Methods: We recruited patients between 2014 and 2016 who had a BMI ≥50 and planned to undergo LSG (n = 25) to participate in an open-label trial. Participants took phen/top (7.5/46-15/92 mg/d) for at least 3 months preoperatively and 2 years postoperatively. We compared weight loss, BMI changes, and odds for achieving BMI <40 for phen/top + LSG to historical controls. Controls had an initial BMI ≥50 and underwent LSG, without phen/top, at our center during the same timeframe (n = 40).

Results: Of the 25 participants recruited, 13 completed LSG. Phen/top participants had a baseline BMI of 61.2 ± 7.1 kg/m² compared with 57.0 ± 5.6 kg/m² for control participants. Percent initial weight loss was -39.3% (phen/top + LSG) versus -31.4% (control) at 12 months, P = .018; by 24 months, phen/top + LSG had an 11.2% greater initial weight loss, P = .007. At 24 months, the mean BMI was 33.8 kg/m² for phen/top versus 42 kg/m² for controls. The odds ratio for achieving a BMI <40 at 2 years with phen/top + LSG versus LSG alone was 4.1 (95% confidence interval, 0.8-21).

Conclusions: Compared with LSG alone, phen/top combined with LSG may help patients with a BMI >50 achieve greater weight loss and reach a BMI <40. Long-term, controlled trials are needed to follow up these results.

Keywords: Antiobesity medication; Phentermine/topiramate extended release; Sleeve gastrectomy; Super obesity.