Search

PURPOSE: Undergoing Roux-en Y gastric bypass (RYGB) is expected to affect orally administered drug absorption. Statins are commonly prescribed to patients with obesity for the prevention of atherosclerotic cardiovascular diseases by lowering cholesterol. This is the first longitudinal prospective study on impacts of RYGB on weight loss, pharmacodynamics and pharmacokinetics of atorvastatin, rosuvastatin, and simvastatin, and their active metabolites, up to one-year post-surgery. METHODS: Forty-six patients were recruited, five patients on atorvastatin, twelve on rosuvastatin, nine on simvastatin, and twenty on no statin. The concentrations of atorvastatin rosuvastatin, and simvastatin with their active metabolites were monitored. RESULTS: Mean plasma concentrations of atorvastatin and metabolites, and rosuvastatin normalized by the unit dose [(nM)/(mg/kg)] decreased by 3 to 6 months post-surgery. Conversely, simvastatin and its metabolite concentrations increased up to 6 months post-surgery, then declined to pre-operative levels by one-year post-surgery. The metabolisms of atorvastatin to hydroxyl-metabolites and simvastatin to simvastatin acid were decreased after RYGB. The weight loss and PD outcomes were comparable between statin and non-statin groups suggesting the key impacts were from RYGB. The discontinuation or reduction of dose of atorvastatin or rosuvastatin post-RYGB exhibited rebounds of LDL levels in some subjects, but the rebound was not apparent with patients on simvastatin pre-surgery. CONCLUSION: Discontinuations of statin dosing post-RYGB require LDL monitoring and reducing the dose to half seems to have better results. Patients on statin treatment post-RYGB should be followed-up closely based on our pharmacokinetic findings, to ensure therapeutic effects of the treatment with minimal adverse effects.

Roux-en-Y gastric bypass procedure is the most frequently performed bariatric surgery for the extremely obese in USA. However, the information about the effects of racial/ethnic differences, comorbidities, and medication use on weight loss outcomes is limited. The objectives of this study were to investigate if race/ethnicity, comorbidities, and medication use affect weight loss effectiveness after the surgery. This is a retrospective observational study conducted at one teaching hospital at Houston metropolitan area, TX, USA. Patients between 18 and 64 years, with body mass index (BMI) of ≥40 or BMI of ≥35 with comorbidities, who had completed medical evaluations/consultations and met insurance policy requirements, were included in the study. From a total of 40 patients in the study (40 % African Americans, 35 % Caucasians, 17.5 % Hispanics, 7.5 % others), the weight loss was significantly greater in Caucasian patients at 6 months after the surgery, with mean percentage excess weight loss (%EWL) of 40.6 ± 17.3, as compared to all other racial groups combined at %EWL of 30.9 ± 11.5 (p value 0.04). No association was found between the 6-month weight loss and other variables including age, gender, BMI prior to surgery, comorbidities, and total number of medications taken before the surgery. This study found that Caucasian patients had a significantly greater %EWL at 6 months post-op as compared to their African-American and Hispanic counterparts. No other variables exhibited significant impact on the weight loss. Further studies with a larger sample size are needed to confirm the results from this study.