title: Oral bioavailability of moxifloxacin after Roux-en-Y gastric bypass surgery. The Cochrane Collaboration’s tool for assessing risk of bias in randomised trials Lifestyle, diabetes, and cardiovascular risk factors 10 years after bariatric surgery. Impact of Bariatric Surgery on the Pharmacokinetics Parameters of Amoxicillin
abstract: OBJECTIVES Roux-en-Y gastric bypass surgery is the most commonly performed procedure for the treatment of morbid obesity . This anatomical alteration may affect the absorption and consequently the bioavailability of oral drugs . This study aims to investigate the oral bioavailability of moxifloxacin in 12 healthy volunteers who underwent gastric bypass surgery .  PATIENTS AND METHODS In this r and omized crossover study , each subject received two single st and ard doses of 400 mg of moxifloxacin orally or intravenously administered on two occasions separated by a washout period of 1 week . Serial venous blood sample s were drawn up to 72 h after dosing and  moxifloxacin plasma levels were measured by a vali date d HPLC method with fluorescence detection . [ clinical trials.gov data base ( identifier : NCT01130922 ) . ] RESULTS After oral dosing , moxifloxacin plasma concentrations reached a maximum ( C(max ) ) of 3.38 ± 1.41 mg/L after 1.75 h ( 0.75 - 4.00 ) . After intravenous dosing , C(max ) and T(max ) were 4.53 ± 1.43 mg/L and 1.03 h ( 0.75 - 2.50 ) , respectively . The mean areas under the plasma concentration time curve extrapolated to infinity ( AUC(∞ ) ) were 46.2 ± 1.4 mg · h/L after oral dosing and 52.3 ± 1.3 mg · h/L after intravenous dosing , result ing in a mean oral bioavailability of 88.32 % [ 90 % confidence interval ( CI ) 85.64%-91.08 % ] . CONCLUSIONS This study confirms that exposure to moxifloxacin is equivalent for oral and intravenous administration of 400 mg dosages in healthy volunteers who underwent gastric bypass surgery . But these exposures were more than 50 % higher than those described for subjects without gastric bypass . This may suggest a higher enterohepatic recirculation of moxifloxacin after gastric bypass Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more BACKGROUND Weight loss is associated with short-term amelioration and prevention of metabolic and cardiovascular risk , but whether these benefits persist over time is unknown . METHODS The prospect i ve , controlled Swedish Obese Subjects Study involved obese subjects who underwent gastric surgery and contemporaneously matched , conventionally treated obese control subjects . We now report follow-up data for subjects ( mean age , 48 years ; mean body-mass index , 41 ) who had been enrolled for at least 2 years ( 4047 subjects ) or 10 years ( 1703 subjects ) before the analysis ( January 1 , 2004 ) . The follow-up rate for laboratory examinations was 86.6 percent at 2 years and 74.5 percent at 10 years . RESULTS After two years , the weight had increased by 0.1 percent in the control group and had decreased by 23.4 percent in the surgery group ( P<0.001 ) . After 10 years , the weight had increased by 1.6 percent and decreased by 16.1 percent , respectively ( P<0.001 ) . Energy intake was lower and the proportion of physically active subjects higher in the surgery group than in the control group throughout the observation period . Two- and 10-year rates of recovery from diabetes , hypertriglyceridemia , low levels of high-density lipoprotein cholesterol , hypertension , and hyperuricemia were more favorable in the surgery group than in the control group , whereas recovery from hypercholesterolemia did not differ between the groups . The surgery group had lower 2- and 10-year incidence rates of diabetes , hypertriglyceridemia , and hyperuricemia than the control group ; differences between the groups in the incidence of hypercholesterolemia and hypertension were undetectable . CONCLUSIONS As compared with conventional therapy , bariatric surgery appears to be a viable option for the treatment of severe obesity , result ing in long-term weight loss , improved lifestyle , and , except for hypercholesterolemia , amelioration in risk factors that were elevated at baseline Background Bariatric surgery leads to several anatomo-physiological modifications that may affect pharmacokinetic parameters and consequently alter the therapeutic effect of drugs , such as antibiotics . The pharmacokinetics of oral amoxicillin after Roux-en-Y gastric bypass ( RYGB ) surgery is unknown . Objectives The objective of this study was to evaluate the impact of bariatric surgery on the pharmacokinetics of  amoxicillin . Methods This study was performed as a r and omized , open-label , single-dose clinical trial , with two periods of treatment , in which obese subjects ( n = 8) received an amoxicillin 500 mg capsule orally before and 2 months after the RYGB surgery . The  amoxicillin plasma concentration was determined by liquid chromatography coupled to mass spectrometry ( LC-MS/MS ) . Results After the surgery , the mean weight loss was 17.03 ± 5.51 kg , and mean body mass index ( BMI ) decreased from 46.21 ± 2.82 to 38.82 ± 3.32 kg/m2 . The mean amoxicillin area under the plasma concentration versus time curve from time zero to the time of the last quantifiable concentration ( AUC0–tlast ) increased significantly ( 3.5-fold ) ; the maximum plasma concentration ( Cmax ) increased 2.8-fold after the bariatric surgery . No correlation was found between amoxicillin absorption , BMI , and weight loss percentage . Conclusion The alterations observed in the amoxicillin pharmacokinetics suggest that obese subjects included in this trial had a substantially increase in amoxicillin systemic exposure after RYGB surgery . However , despite this increase , its exposure was lower than the values reported for non-obese volunteers . 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target: Patients given oral beta-lactams and macrolides warrant close monitoring due to unpredictable absorption post-bariatric surgery , whereas oral fluoroquinolones and linezolid may not be affected .
  Several studies also showed decreased absorption following RYGB , as well as lower serum exposure in patients with obesity compared to non-obese controls .
background: The purpose of this study was to conduct a systematic review of the existing literature to determine the effect of bariatric surgery on various pharmacokinetic parameters of oral antibiotic absorption as well as overall patient outcomes .