4/29/2013. Discuss the risks and benefits of various bariatric surgery procedures

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1 Discuss the risks and benefits of various bariatric surgery procedures Michelle Musser, PharmD Assistant Professor of Pharmacy Practice Ohio Northern University Describe the implications of bariatric surgery on medication use and management Outline strategies to address medication use issues in bariatric surgery patients including micronutrient supplementation. Practical approach to assess body fat Issues with interpretation in some patients Treatment of Obesity Category BMI (kg/m 2 ) Overweight Obese (class I) Moderately obese (class II) Morbidly obese (class III) Super morbidly obese (class IV) >50 Measure of abdominal fat Useful in BMI under 35 kg/m 2 to predict risk for obesity-related disease states Independent risk predictor High risk measurements Males: >40 inches Females: >35 inches Waist circumference Obesity Class Useful in BMI under 35 kg/m2 Male Independent risk predictor High risk measurements Males: >40 inches Females: >35 inches sd asd BMI (kg/m 2 ) Disease Risk (Relative to Normal Weight and Waist Circumference) Male <40 inches Women <35 inches Overweight Increased High Obese (class I) Moderately obese (class II) Morbidly obese (class III) Super morbidly obese (class IV) High Very High Very High Very High Male >40 inches Women >35 inches Extremely High Extremely High >50 Extremely High Extremely High 1

2 In , 68.2% of adults in the United States were overweight or obese Nearly 155 million overweight or obese adults In , 35.7% of adults in the United States were obese Over 78 million obese adults In 2000, obesity was associated with nearly 112,000 excess deaths relative to normal weight individuals In 2008, the total cost of obesity was estimated at $147 billion Expected to reach $861 to $957 billion by 2030 NCHS Data Brief. 2012: No. 82 Heart Disease and Stroke Statistics-2013 Update Heart Disease and Stroke Statistics-2013 Update Increased risk of many health conditions Type 2 diabetes mellitus* Hypertension Osteoarthritis Sleep apnea* Cancer Coronary heart disease and other atherosclerotic diseases* Gastroesophageal reflux disease Infertility/gynecological abnormalities Gallstones Weight loss Reduce risk of concurrent disease states Improve quality of life Which of the following are options for the treatment of obesity? A: Reduce caloric intake by 500 to 1000 calories daily B: Encourage moderate-intensity physical activity for a long-term goal of 30 minutes most days of the week C: Add pharmacological therapy to lifestyle changes D: All of the above Risk factor management Weight loss modalities Lifestyle changes Pharmacological agents Bariatric surgery 2

3 Non-modifiable Family history of coronary heart disease Age Recommended in obese and overweight patients or patients with a high-risk waist circumference and two or more risk factors Modifiable Risk Factor Smoking Hypertension Dyslipidemia Impaired blood glucose or uncontrolled type II diabetes mellitus Management Smoking cessation Per JNC VII Per ATP III Per ADA guidelines Initial goals is weight loss of 10% of body weight over 6 months with loss of 1-2 pounds each week Lifestyle changes include physical activity and dietary modifications Reduction of caloric intake by 500 to 1000 calories each day 1000 to 1200 kcal/day for women 1200 to 1600 kcal/day for men Long term goal of physical activity at least 30 minutes or more of moderate intensity activity most days of the week Patients can expect to lose 10-12% of their initial weight over 6 to 12 months with lifestyle changes with or without pharmacological agents Most patients regain any weight lost within 5 years Cleve Clinic J Med. 2002; 69(11): Pharmacological agents can be used as an adjunct to lifestyle changes in patients with BMI >30 or BMI >27 with concurrent obesity-related risk factors Adverse effects Stop use if weight loss is not adequate Criteria for new weight loss drug approval Mean weight loss with treatment >5% more than mean weight loss with placebo after 1 year Greater percent of patients losing >5% of baseline weight with treatment at 1 year compared to placebo Am J Surg. 2002; 184: 9S-16S Drug Diethylproprion (Tenuate) Lorcaserin (Belviq) Phenteramine (Adipex-P, Suprenza) Phenteramine +topiramate (Qsymia) Orlistat (Alli, Xenical) Weight Loss 3 kg (6.6 pounds) over 6-12 months 3.6 kg (8 pounds) over 2 years 3.6 kg (8 pounds) over 2-24 weeks 9 kg (20 pounds) at 1 year 3.45 kg (7.6 pounds) at 1 year Side effects Dependence Cardiovascular CNS stimulation Bone marrow suppression Hypoglycemia Cognition issues Changes in blood counts Bradycardia Dependence Cardiovascular CNS stimulation Paraesthesia Dysgeusia Memory issues GI side effects Cautions - Stop after 4 weeks if at least 1.8 kg (4 pounds) is not lost -Schedule IV -Limited duration of use - Do not use in pregnancy - Avoid use with serotonergic drugs - Stop if at least 5% weigh loss is not achieved by 12 weeks - Avoid use with SSRI -Schedule IV -Limited duration of use - Do not use in pregnancy - Reduced fat soluble vitamin absorption PL-Detail Document, Drugs for Weight Loss

4 Which of the following options for the treatment of obesity have been proven to lead to LONG- TERM weight loss? A: Bariatric surgery B: Reduce caloric intake by 500 to 1000 calories daily Procedures and Complications C: Encourage moderate-intensity physical activity for a long-term goal of 30 minutes most days of the week D: Add pharmacological therapy to lifestyle changes Which of the following is a potential benefit associated with bariatric surgery in the treatment of obese patients? A: Improvement in long term weight loss B. Improvement in mortality rates Improved weight loss Results in 40-75% excess weight loss 70% of patients able to sustain a 50% excess weight loss for at least 5 years C. Reduction in use of antidiabetic medications D. All of the above Cleve Clinic J Med. 2002; 69(11): Improvement in obesity-related conditions Remission of type 2 diabetes mellitus in 75% of patients in 2 years following surgery compared to medical therapy Higher remission rates in hypertension, elevated triglycerides levels, and low HDL levels have been shown in other studies Reductions in number of medications used to treat hypertension and diabetes Improved mortality Patients undergoing surgery had a mortality rate of 9% compared to 28% in patients who were approved for surgery, but did not undergo surgery For each year of follow-up after surgery, bariatric surgery patients had 1% mortality rate compared to 4.5% in patients not undergoing surgery Heart Disease and Stroke Statistics-2013 Update Ann Pharmacother. 2005; 39: Cleve Clinic J Med. 2002; 69(11):

5 Cost saving Bariatric surgery pays for itself in ~3 years due to reduced health care expenditures 45% of patients previously receiving public assistance found full or part-time employment following surgery Mortality risk Postoperative complications Gastrointestinal complications Nutritional complications Need for life-long care and monitoring Cleve Clinic J Med. 2002; 69(11): Option in certain patients In 2004, the National Coverage Advisory Committee recommended offering bariatric surgery to Medicare beneficiaries with >BMI 35 kg/m 2 with 1 obesity related comorbidity American College of Physicians recommended bariatric surgery in patients with BMI >40 kg/m 2 and a concurrent medical condition American Association of Clinical Endocrinologists (AACE), the Obesity Society (TOS), and the American Society of Metabolic and Bariatric Surgery (ASMBS) guidelines recommend consideration of bariatric surgery in patients with BMI >40 kg/m 2 or with BMI >35 kg/m 2 with co-existing medical conditions US Pharm. 2007; 32(9):HS US Pharm. 2007; 32(9):HS AACE/TOS/ASMBS guideline selection criteria Factor Criteria Weigh loss history Failure of previous nonsurgical attempts at weight loss Malabsorptive Bilopancreatic diversion (BPD) with or without duodenal switch Commitment Exclusion Expectation that patients will adhere to postoperative care Reversible causes of obesity Current drug or alcohol abuse Uncontrolled, severe psychiatric illness Lack of comprehension of risks, benefits, expected outcomes, alternatives, and lifestyle changes required Restrictive Vertical banded gastroplasty (VBG) Laparoscopic adjustable gastric banding (LAGB) Combination Roux-en-Y gastric bypass (RYBG) US Pharm. 2007; 32(9):HS

6 Medline Plus: Biliopancreatic diversion with duodenal switch at Medline Plus: Biliopancreatic diversion at Medline Plus: Roux-en-Y stomach surgery for weight loss at Which of the following bariatric procedures is likely to produce the MOST weight loss? A: LAGB B: RYGB C: BPD Medline Plus: Veritical banded gastroplasty at Medline Plus: Adjustable gastric banding at Type of Procedure Excess Weight Loss After Surgery (%) 1-2 years 7-10 years BPD High Risk of Nutritional Complications RYGB Moderate VBG n/a Low Gastric banding Low Mortality rate is estimated at % Pulmonary embolism Serious surgical complications Anastomotic leak Postoperative complications Bleeding Thrombosis Wound issues Pulmonary issues. US Pharm. 2007; 32(9):HS

7 Gastrointestinal complications Cholelithiasis Dumping syndrome Vomiting Diarrhea/steatorrhea Additional considerations Fertility and pregnancy Psychological issues Nutritional issues Management and the Role of the Pharmacist Cleve Clinic J Med. 2006; 73(11): Am J Med Sci. 2006; 331 (4): Bariatric surgery and medication use. Pharmacist's Letter 2009 What micronutrient deficiencies are likely to occur following bariatric surgery? AACE/TOS/ASMBS guideline recommendations A: Iron deficiency B: Vitamin D deficiency C: Calcium deficiency D: All of the above All Bariatric Surgery Patients Daily multivitamin with at least 400 mcg of folic acid Calcium mg daily Vitamin D mg daily Patients Undergoing Malabsorptive Procedures Iron mg daily Vitamin B12 Not typically seen in LAGB Mechanism Decreased absorption Poor mixing of pancreatic/biliary secretions Calcium deficiency Secondary hyperparathyroidism Bone loss and osteoporosis Supplementation in case of severe deficiency (25-hydroxyvitamin D (25-OHD) <30 ng/ml) Ergocalciferol (vitamin D 2 (Drisdol)) 50,000 units once to three times weekly Doses of 50, ,000 units daily may be needed Calcitriol (Rocaltrol) may be needed if 25-OHD levels remain low 7

8 Treatment of osteoporosis with bisphosphonate once calcium and vitamin D are normalized Intravenous agents preferred Zoledronic acid (Reclast) Ibandronate (Boniva) Monitoring Bone density measurements Labs Parathyroid hormone (PTH) Serum calcium 25-OHD Not typically seen in LAGB Mechanism Decreased intake of calcium-containing foods Bypassing of absorption sites Vitamin D deficiency Supplementation Calcium citrate is preferred due to better absorption Higher ph of gastric pouch limits absorption of carbonate salt Common after RYGB and BPD Mechanisms Reduced gastric acid production limits conversion of dietary iron and absorption Inadequate intake Reduced absorption Anemia Supplementation Oral supplements may be poorly tolerated Can use sulfate, fumarate, or gluconate salts Avoid slow release or enteric coated preparations 8

9 Supplementation Give with vitamin C Use parenteral agents when oral supplementation is inadequate Iron dextran (INFeD) Ferumoxytol (Feraheme) Iron sucrose (Venofer) Ferric gluconate (Ferrlecit) Common after RGYB and BPD Mechanisms Low gastric acid limit release from meat Limited intake of vitamin B12 containing food Decrease intrinsic factor availability Anemia Glossitis Neuropathies Supplementation May be accomplished by: >350 micrograms/day orally 1000 micrograms/month IM 3000 micrograms every 6 months IM 5000 micrograms every week intranasally (Nascobal) Common after RGYB and BPD Less likely than vitamin B12 deficiency Mechanisms Reduced nutritional intake Anemia Glossitis Elevated homocysteine Supplementation suggested via multivitamin regimen Not typically seen in RYGB or restrictive procedures Night blindness Vision loss Treatment Supplementation until levels normalize following surgery Continued monitoring Not typically seen in RYGB or restrictive procedures Anemia Peripheral neuropathy Treatment Supplementation usually not needed 9

10 Not typically seen in RYGB or restrictive procedures Bleeding issues Treatment Supplementation if international normalized ratio (INR) >1.4 Evaluate levels in cases of bleeding Phosphorus Zinc Thiamine Copper Selenium Magnesium Preparation for life-long supplementation Evaluate patient for deficiencies and related complications Ensure supplementation where appropriate Ensure consistent monitoring and adjustment of supplementation regimen Ensure adherence to supplementation Difficulty in supplementation adjustment Adherence issues Cost concerns Lack of guidelines Lack of consistency among patients What medications should be avoid in a patient who has undergone bariatric surgery? A: Ibuprofen Management and the Role of the Pharmacist B: Venlafaxine XR C: Fosamax D: All of above 10

11 Adjustment of medications for concurrent disease states Inability to use oral formulations Changes in medication disposition Factor Reduced acidity of gastric pouch Slowed gastric emptying Reduced surface area for absorption Decreased transient time and length of GI tract Changes in exposure to drug transporter Implications Changes in availability of ionized or unionized species of a medication, leading to changes in absorption Slowed delivery of medications to small intestine may reduce absorption Bypassing of portion of the small intestine reduce area for absorption Inadequate transient time for full dissolution and absorption Transporter s in the proximal small intestine are bypassed and may impact drug disposition Drug Affected NSAIDs: ionized drug solubility absorption Ketoconazole Enteric-coated formulations Warfarin Amiodarone OATPs: Erythromycin, thyroxine, fexofenadine, PEPT-1: cephalosporins, ACEI J Am Pharm Assoc. 2008; 48 (4): Am J Health-Syst Pharm. 2006;63: US Pharm. 2007; 32 (9): HS27-HS37 Am J Health Syst-Pharm. 2011; 68: Altered enterohepatic recycling Unpredictable levels due to decreased contact with proximal small intestine and altered blood flow Oral contraceptives Am J Health-Syst Pharm. 2006;63: Am J Health Syst-Pharm. 2011; 68: Other affected medication classes Antidepressants (SSRI, venlaxfaxine) Reduced bioavailability possible Metformin Improved bioavailability possible HMG CoA reductase inhibitors (atorvastatin) Variable change in bioavailability Antihypertensives (propanolol) Reduced absorption Monitoring of concurrent disease states Use of alternative dosage forms Avoidance of extended release, delayed release, and enteric coated formulations Use of immediate release formulation may impact compliance Need for close monitoring for efficacy and side effects especially in medication likely to undergo changes in absorption Obes Surg. Published online Feb 2013 Education prescribers and patients about proper medication selection Identify regimens in need of close monitoring Suggesting alternative regimens or monitoring parameters Reduction in complexity of medication regimens Consider interactions with supplementation Need to keep an updated medication list 11

12 Bariatric surgery and medication use. Pharmacist s Letter/Prescriber s Letter 2009;25(11): Brethauer SA, et. al. Risks and benefits of bariatric surgery: current evidence. Cleve Clinic J Med. 2006;73(11): Choban PS, et. al. Bariatric surgery for morbid obesity: why, who, when, how, where, and then what? Cleve Clinc J Med.2002;69(11): Fisher BL and Schauer P. Medical and surgical options in the treatment of severe obesity. Am J Surg. 2002; 184: 9S-16S Go AS, et. al. Heart Disease and Stroke Statistics-2013 Update: A Report from the American Heart Association. Circulation. 2013; 27: e Hunteman LM. Potential role of medication therapy management for bariatric surgery patients. J Am Pharm Assoc.2008;48(4):440,442. Malone M. Recommended Nutritional Supplements for Bariatric Surgery Patients. Ann Pharmacother. 2008; 42: Malone M, Alger-Mayer SA. Medication use patterns after gastric bypass surgery for weight management. Ann Pharmacother.2005;39: Mechanick JI, et. al. American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic and Bariatric Surgery medical guidelines for clinical practice for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient. Surg Obes Relat Dis.2008;4:S109-S184. Miller AD, Smith KM. Medication and nutrient administration considerations after bariatric surgery. Am J Health-Syst Pharm.2006;63: Ogben CL, et. al. Prevalence of Obesity in the United States, NCHS Data Brief. 2012; No. 82: 1-8. NHLBI Obesity Education Initiative Expert Panel on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. The Practical Guide Identification, Evaluation, and Treatment of Overweight and Obesity in Adults Parke E. Nutritional Management of Patients after Bariatric Surgery. Am J Med Sci. 2006; 331 (4): PL-Detail Document, Drugs for Weight Loss. Pharmacist s Letter. April 2012 Smith A, et. al. Pharmacokinetics considerations in Roux-en-Y gastric bypass patients. Am J Health Syst- Pharm. 2011; 68: Whipple Guthrie, E. Bariatric surgery: what all pharmacists need to know. US Pharm. 2007;32(9):HS27-HS37. Yska, et. al. Influence of Bariatric Surgery on the Use and Pharmacokinetics of Some Major Drug Classes. Obes Surg. Published online Feb 2013 Michelle Musser, PharmD Assistant Professor of Pharmacy Practice Ohio Northern University 12