Fall CE SeriesNovember 7th, 2019
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Bariatric Surgery and Medication Management
Lillian Clark, PharmD, MBAHealth-System Pharmacy Administration PGY2
University of Utah [email protected]
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Disclosure
Relevant Financial Conflicts of InterestCE Presenter, Lillian Clark PharmD, MBA: noneCE mentor, Jolena Hagan PharmD, CACP: noneOff-Label Uses of Medications: None
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Pharmacist Learning Objectives1. Differentiate bariatric surgeries and their impact on medication absorption.
2. Choose preferred options within selected drug classes for patients following bariatric surgery.
3. Recall patient counseling points to promote safe and effective therapy following bariatric surgery.
4. Design a medication plan to minimize adverse effects following bariatric surgery
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Technician Learning Objectives1. Identify nutrient deficiencies among bariatric surgery recipients.
2. Recognize over the counter medications that should be avoided in bariatric surgery patients.
3. Select medication formulations that should be avoided in patients following bariatric surgery.
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• Background information• Surgeries
• Nutrients and supplementation
• Medications and formulations to avoid
Roadmap
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Trends
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50,000
100,000
150,000
200,000
250,000
2011 2012 2013 2014 2015 2016 2017
Number of surgeries
Year
Total Bariatric Surgeries
Estimated future 6-8% increase in volume per year
American Society for Metabolic and Bariatric Surgery;; Estimate of Bariatric Surgery Numbers, 2011-2017, 2018
Sleeve gastrectomy 59%
Roux-En-Y gastric bypass (RYGB) 18%
Revision 14% Gastric banding 3%
228,000 cases in 2017
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Breakdown of surgeries
Cases performed represent ~ 1% of eligible patients
American Society for Metabolic and Bariatric Surgery;; Estimate of Bariatric Surgery Numbers, 2011-2017, 2018
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Bariatric Surgery Eligibility 1.BMI of 40 kg/m2 or more
2. BMI of 35 kg/m2 with an obesity related condition such as diabetes, heart disease, or sleep apnea
3. BMI 30-34.9 kg/m2 with an obesity related condition such as diabetes, heart disease, or sleep apnea
NIDDK Potential Candidates for Bariatric Surgery, 2016Aminian et al., 2018
2015-2016:~40% of Americans over age 20 obese~72% of Americans over age 20 overweight (including obese)
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Obesity BMI (kg/m2) Classification
<18.5 Underweight
18.5 -‐25 Normal
25 -‐30 Overweight
30-‐34.9 Obesity class I
35-‐39.9 Obesity class II
Above 40 Obesity class II
CDC Defining Adult Overweight and Obesity, 2017CDC Obesity and Overweight, 2016
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Prevalence of Self-Reported Obesity Among U.S. Adults 2018
CDC Adult Obesity Prevalence Maps, 2019
• Resects 80% of stomach longitudinally
Vertical sleeve gastrectomy (VSG)
• Stomach stapled to form pouch that connects to distal jejunum
Roux-En-Y gastric bypass (RYGB)
• Silicone band around stomach to create smaller pouch
Adjustable gastric band (AGB)
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Bariatric Surgeries
American Society for Metabolic and Bariatric Surgery, Bariatric Surgery Procedures
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Sleeve Gastrectomy •Removes approximately 75-80% of the stomach
•Stomach that remains resembles the shape and size of a banana (100-120 mL)
•Restrictive
•Can be done laparoscopically American Society for Metabolic and Bariatric Surgery, Bariatric Surgery ProceduresNIH National Institute of Diabetes and Digestive and Kidney Disease, Types of Bariatric SurgeryImage: https://en.wikipedia.org/wiki/Sleeve_gastrectomyimage: https://www.niddk.nih.gov/health-‐information/weight-‐management/bariatric-‐surgery/types#gastric-‐bypass
Advantages
• Restricts amount of food within the stomach
• Promotes rapid and significant weight loss (50-60%)
• No foreign objects and no re-routing of GI system
• Less complex surgical option • Promotes positive gut hormone changes
Disadvantages
• Permanent• Difficulty with adequate nutrition • Risks for complications (sleeve leak, infections)
• Risk of heartburn (~15%)
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Sleeve Gastrectomy
American Society for Metabolic and Bariatric Surgery, Bariatric Surgery ProceduresNIH National Institute of Diabetes and Digestive and Kidney Disease, Types of Bariatric SurgeryEl-‐Hadi et al., Can J Surg. 2014
•“Gastric Bypass” •Malabsorptive•Can be done laparoscopically •Simplified steps:1. Small stomach pouch (holds ~30 mL in volume) created and divided from the rest of the stomach
2. The pouch is connected to the middle of the small intestine (past the duodenum)
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Roux-En-Y Gastric Bypass (RYGB)
American Society for Metabolic and Bariatric Surgery, Bariatric Surgery ProceduresNIH National Institute of Diabetes and Digestive and Kidney Disease, Types of Bariatric SurgeryImage: https://en.wikipedia.org/wiki/Gastric_bypass_surgeryImage: image: https://www.niddk.nih.gov/health-‐information/weight-‐management/bariatric-‐surgery/types#gastric-‐bypass
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Roux-En-Y Gastric Bypass (RYGB)Advantages
• Restricts amount that can be consumed• Promotes significant weight loss (~70%)• Promotes positive gut hormone changes
Disadvantages
• More complex operation• Long term vitamin deficiencies• Risks for complications
American Society for Metabolic and Bariatric Surgery, Bariatric Surgery ProceduresNIH National Institute of Diabetes and Digestive and Kidney Disease, Types of Bariatric Surgery
-A ring/band is placed around the top of the stomach to make a small pouch -Band is inflatable and can be adjusted-Patient will feel full with small amounts of food -Can be done laprascopically
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Adjustable Gastric Band
American Society for Metabolic and Bariatric Surgery, Bariatric Surgery ProceduresNIH National Institute of Diabetes and Digestive and Kidney Disease, Types of Bariatric SurgeryImage: https://en.wikipedia.org/wiki/Bariatric_surgeryImage: image: https://www.niddk.nih.gov/health-‐information/weight-‐management/bariatric-‐surgery/types#gastric-‐bypass
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Adjustable Gastric BandAdvantages
• Adjustable• Reversible• No cutting or re-routing of stomach/GI system • Lowest risk for vitamin deficiencies
Disadvantages
• Less weight loss (~40%) • Follow up necessary to adjust band • Foreign body remains (band can slip/erode)
American Society for Metabolic and Bariatric Surgery, Bariatric Surgery ProceduresNIH National Institute of Diabetes and Digestive and Kidney Disease, Types of Bariatric Surgery
Restrictive component
Malabsorptive component
Roux-‐En-‐Y Roux-‐En-‐Y
Gastric banding Biliopancreatic diversion with duodenal switch (rarely used)
Gastric sleeve
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Mechanism of bariatric surgery
Restrictive surgeries have fewer pharmacokinetic alterations than malabsorptive surgeries
American Society for Metabolic and Bariatric Surgery, Bariatric Surgery Procedures
Partitioning the stomach:-Anatomical changes -Physiological changes -Increase gastric pH and decreases surface area for absorption
Bypass portions of the small intestine-Efflux transports can increase/decrease absorption of medications
Select which surgery is most likely to impact medication absorption and select the primary mechanism associated with the surgery:A. Roux-En-Y, malabsorptive B. Gastric sleeve, malabsorptive C. Adjustable gastric banding, restrictive D. Gastric sleeve, restrictive
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Audience Response Question #1
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Roadmap• Background information• Surgeries
• Nutrients and supplementation
• Medications and formulations to avoid
Common nutrient deficiencies: •Calcium•Copper•Folate •Iron•Thiamine •Vitamin B12•Vitamin D •Zinc
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Nutrient supplementation More issues with malabsorptive surgeries than restrictive
• Anemia 33-49% within 2 years in patients following bariatric surgery
• Vitamin B12 deficiency within 5 years in 19-35% of patients following RYGB
US Pharm. 2016;41(12):HS2-HS8.American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient 2016 Update: MicronutrientsImproving Adherence to Micronutrient Supplementation in the Metabolic and Bariatric Surgery Patient Population, 2017
•Natural absorption through gastric pH breakdown in the stomach and bound to be absorbed in ileum •Dietary changes •Non-adherence to replacement regimen•Lack of knowledge•Surgical team vs. primary car team and long term follow up •Differences amongst surgery types •Generalized symptoms of deficiencies •Misconception from patients and providers regarding the importance of supplementation
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Causes of deficiencies
Management of Patients Receiving, 6th edition Bariatric Surgery
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Calcium Nutrient Notes Recommended
daily doseResult of deficiency
Calcium Calcium citrate recommended
Avoid calcium carbonateproducts (Tums, OsCal, Caltrate, oyster shell)
1200-1500 mg of elemental calcium
Asymptomatic Altered mental statusGeneralized weaknessàOsteoporosisàFractures
American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient 2016 Update: MicronutrientsManagement of Patients Receiving Bariatric Surgery, 6th edition Long-‐term pharmacotherapy considerations in the bariatric surgery patient, 2016
Counsel to not take calcium with iron– because calcium may impair iron absorption!
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CopperNutrient Notes Recommended
daily doseResult of deficiency
Copper Symptoms can manifest up to 10 years following surgery
1-2 mg
10-20% of patients are deficient after RYGB
Cytopenias, fatigue neurologic changes
American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient 2016 Update: MicronutrientsRobinson SD, Cooper B, Leday TV. Copper deficiency (hypocupremia) and pancytopenia late after gastric bypass surgery. Proc (Bayl Univ Med Cent). 2013;
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FolateNutrient Notes Recommended
daily doseResult of deficiency
Folate Primarily due to decrease in dietary folate
400-800 mcg
800-1000 mcg if women of child bearing age
Anemia, neuropathy, fatigue, heart palpitations
American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient 2016 Update: Micronutrients
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ThiamineNutrient Notes Recommended
daily doseResult of deficiency
Thiamine -Requires whole blood for measurement
-Risk increases with other identified risk factors such as alcoholism, malnutrition
12-50 mg
At least 12 mg recommended and preferably 50 mg
Neuropathy,Beriberi, Wernicke’s encephalopathy,Wernicke–Korsakoffsyndrome
American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient 2016 Update: MicronutrientsLong-‐term pharmacotherapy considerations in the bariatric surgery patient, 2016
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Vitamin B12 Nutrient Notes Recommended daily
doseResult of deficiency
Vitamin B12 Oral, sublingual, or injectable routes available-Deficiency due to absence of gastric acid reduces absorbable dietary source-Lack of intrinsic factor also contributes to deficiency
350-500 mcg Anemia, neuropathy, cognitive difficulties
American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient 2016 Update: Micronutrients
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IronNutrient Notes Recommended
daily doseResult of deficiency
Iron Not all multi-vitamin products contain iron
18 mg Anemia, neuropathy, cognitive difficulties, fatigue
American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient 2016 Update: Micronutrients
Counsel patients to take with juices or other acidic snacks to maximize absorption
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ZincNutrient Notes Recommended
doseResult of deficiency
Zinc For every 8-15 mg of zinc, it is recommended to supplement with 1 mg of copper
8-22 mg/d Skin lesions, poor wound healing, hair loss
American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient 2016 Update: MicronutrientsManagement of Patients Receiving Bariatric Surgery, 6th edition
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Vitamin DNutrient Notes Recommended
daily doseResult of deficiency
Vitamin D Liquid productavailable
3000 IU Asymptomatic, Bone weakness
American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient 2016 Update: Micronutrients
•Adherence declines in the months following surgery
•Nutrient deficiency rates increase the further out from surgery
•Utilize different formulations to assist with absorption and adherence
•Closely review the amounts in combination products
•Standard over the counter (OTC) vitamins may not have adequate amounts of nutrients
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Key Takeaways and Counseling Points
LB is a 36 year old female with a history of Roux-‐en-‐Y gastric bypass (RYGB) surgery 5 years prior. She brings in the following multi-‐vitamin label for a product and asks you if it will appropriately supplement iron and B12.
Select the most appropriate response:
A. LB should switch to a product that contains 20 mg of iron per tablet
B. If the patient takes 2 tablets daily it is appropriate
C. Since LB had RYGB she does not require supplementation
D. If the patient takes 1 tablet daily it is appropriate
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Audience Response Question #2
Product Amount per tablet
Iron 9 mg
Vitamin B12 250 mcg
A patient is considering Roux-‐en-‐Y gastric bypass (RYGB) surgery. She asks you how the surgery could affect medication therapies in the future. Select the most appropriate response.
A. It is possible that the surgery can affect the acidity in the gastrointestinal tract leading to medication absorption changes
B. Since it is only a restrictive surgery, the patient should not worry about absorption of nutrients following surgery
C. During the first 5 years following surgery she will need to take vitamin supplementation, but after that she can stop
D. During surgery a large section of your small intestine is removed
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Audience Response Question #3
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Roadmap • Background information• Surgeries
• Nutrients and supplementation
• Medications and formulations to avoid
-Direct oral anticoagulants (DOACs) should not be used in patients with a BMI >40 kg/m2 or a body weight of >120 kg
Things to consider in bariatric surgery patients:
•Lack of data
•Rivaroxaban reliant on food for proper absorption
•pH dependent absorption and solubility
Warfarin is still preferred due to availability of international normalized ratio (INR) monitoring
Anticoagulants
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Effect of major gastrointestinal tract surgery on the absorption and efficacy of direct oral anticoagulants (DOACS). J Thromb Thrombolysis. 2017; 43: 343-‐351. Oral anticoagulant use after bariatric surgery: a literature review and clinical guidance. Am J Med. 2017; 130(5): 517-‐524.The effect of bariatric surgery on direct-‐acting oral anticoagulant drug levels. Thrombosis Research. 2018;163: 190–195
DOACs
Apixaban
Dabigatran
Edoxaban
Rivaroxaban
Extremely limited medication specific data 1) Tricyclic antidepressants (TCAs): Vd is smaller following RYGB due to lipophilicity 2) Selective serotonin reuptake inhibitors (SSRIs):
Vd is smaller following RYGB due to lipophilicity Decreased bioavailability
No preferred agent
Antidepressants
37. Int J Gen Med. 2014;7:219–224, 2014
•Bariatric surgery recipients should avoid pregnancy 12 months pre operatively and 18 months post operatively •Delay is primarily to improve likelihood that maternal weight will be stable during fetal growth •2014-‐2018 worldwide proportion of female patients = 73.7% and median age at time of operation = 42 years old •Common contraception study exclusion factors: •Women more than 20-‐35 percent above their ideal body weight
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Contraception Recommendations
Am Fam Physician. 2010 Apr 1;81(7):905-‐906. ACOG Practice Bulletin No. 105: Bariatric Surgery and Pregnancy Obstetrics & Gynecology, 113(6):1405-‐1413, June 2009OBES SURG (2019) 29: 782Obstet Gynecol (2017) 130:5
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Recommended contraception methodsContraceptionmethod
COCsor POPs
Patch* Ring IUDs(Cu-‐IUD, LNG-‐IUD)
DMPA
Restrictive Yes Yes Yes Yes Yes
Malabsorptive No Yes Yes Yes Yes
*Ensure to consider patient’s weight following bariatric surgery-Studies have shown possible decreased patch efficacy in patients ≥ 90 kg-Contraception patch included women as much as 35 percent above their ideal body weight.
Bottom line: Patients with malabsorptive bariatric surgery should not receive COCs or POPs
CDC MMWR 2016
COCs= combined oral contraceptivesPOPs= progestin only pillsCu-‐IUD= copper intrauterine deviceLNG-‐IUD= levonorgestrel intrauterine deviceDMPA= depot medroxyprogesterone acetate
•Diabetes mellitus•1/3 of patients w/ RYGB later experience relapse •Median disease free period is ~8 years•Benefits independent of weight loss•Disease remits quickly after surgery prior to weight loss
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Bariatric surgery and long term benefits
Cummings, D.E. & Rubino, F. Diabetologia (2018) 61: 257.
Proposed weight independent glucose lowering mechanisms following surgery1) Gut hormone changes Inc GLP-1 secretion Compromised secretion of ghrelin
2) Changes in bile acid signaling3) Higher glucose metabolism in the small intestine4) Increased insulin sensitivity 5) Reduced glucose transport via SGLT1 6) Reduced branched chain amino acids7)Possible changes in gut microbiota
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Benefits independent of weight loss
Puzziferri N, Almandoz JP. Sleeve Gastrectomy for Weight Loss. JAMA. 2018;319(3):316. doi:10.1001/jama.2017.18519
•Nonsteroidal anti-inflammatory drugs (NSAIDS): •Reduced stomach size increases risk for damage to the stomach pouch and subsequent ulcers•Marginal ulcer= gastric ulcer that develops in the jejunal mucosa near the gastrojejunal anastomoses
•Incidence of post-RYGB margin ulceration 0.6%-16% •Proton pump inhibitors (PPIs) used to prevent and treat marginal ulcers
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OTC medications to avoid
. Radiol Case Rep. 2016;10(2):1063. 2017
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Bisphosphonates Gastroesophageal
injury
Osteoporosis
•Controversial
•Consider intravenous (IV) formulation
Lancet Diabetes Endocrinol. 2014;2(2):165–174
Which of the following over the counter (OTC) medications should be avoided in patients following bariatric surgery?
A. Ibuprofen (Advil)
B. Aspirin/Acetaminophen/Caffeine (Excedrin)
C. Enteric coated aspirin
D. All of the above
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Audience Response Question #4
22% of patients who underwent bariatric surgery were on treatment for Type 2 diabetes before surgery
Metformin: bioavailability of metformin increases 50% following RYGB Use reduced doses Safe to start 3rd day after surgery pending renal function TZDs should be avoided due to potential weight gain Insulin doses should be decreased 50-75% following surgery to prevent hypoglycemia Other medications have limited evidence in bariatric patients following surgery
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Diabetes management following surgery
Schauer PR et al. N Engl J Med 2017;376:641-‐651
A 24 year old female had sleeve gastrectomy 1 month prior and wants to start birth control. Her past medical history is significant for gastroesophageal reflex disease (GERD) and generalized anxiety disorder. Which of the following options would be appropriate for the patient?
A. Copper IUD
B. Levonorgestrel (LNG) IUD
C. Ethinyl estradiol and norethindrone (Lo Estrin)
D. Any of the above
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Audience Response Question #5
A patient visits you in primary care clinic and tells you he is undergoing a gastric sleeve procedure next month. His past medical history includes diabetes, depression, and obstructive sleep apnea. His medications are listed and he asks if his current medications will change after surgery.
Citalopram (Celexa) 20 mg daily Calcium citrate 500 mg BID Insulin glargine 55 units QHSMetformin 500 mg BID (history of diarrhea with higher doses)
Think-‐pair-‐share what, if any, changes the patient may experience after surgery. In addition, what other information may be helpful to know?
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Audience Response Question #6
Abbreviation Meaning
CD Controlled dose/diffusion/delay
CR Controlled release
CRT Controlled release tablet
DR Delayed release
EC Enteric coating
ER Extended release
LA Long acting
SA Sustained action
SR Sustained/slow release
TD Time delay
TR Time release
XL Extra long
XR Extra release
XT Extra time
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Examples:• Methylphenidate (Metadate CD)• Divalproex sodium (Depakote ER)
• Tolterodine (Detrol LA)• Isosorbide dinitrate (IsonateTR)
• Metoprolol (Toprol XL)• Venlafaxine (Effexor XR)• Diltiazem (Cartia XT)
Formulation considerations
A patient brings a prescription for bupropion (Wellbutrin XR) 174 mg daily. While reviewing their profile you notice they have a history of a “bariatric surgery” 15 years prior.
A. Fill the prescription since the surgery was more than 10 years prior
B. Recommend a switch to bupropion (Wellbutrin SR) 75 mg BID
C. Recommend a switch to bupropion (Wellbutrin IR) 75 mg BID
D. Recommend a switch to a different active ingredient
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Audience Response Question #7
Following surgery àliquid àcrushable à”tic-‐tac” sized or smaller
Particularly until anastomoses healed due to risk of stressing or tearing (2-‐3 months)
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We’ve talked about what is avoided… what is used?
•Bariatric surgery is increasingly common and will continue to be seen expanding to additional patient populations•Limited data exists for specific medications and clinical judgement must be considered using knowledge of surgeries and physiological/anatomical impact on medication absorption•It is essential for patients to be reviewed and assessed pre-operatively, peri-operatively, and life long following surgery to continue to prevent adverse reactions•Pharmacists and technicians can help identify medications and formulations not recommended in patients following bariatric surgery and help correct it
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Summary
1.American Society for Metabolic and Bariatric Surgery;; Estimate of Bariatric Surgery Numbers, 2011-2017, 2018
2.Ali Aminian et al., ASMBS updated position statement on bariatric surgery in class I obesity (BMI 30–35 kg/m2), Surgery for Obesity and Related Diseases (2018), https://doi.org/10.1016/j.soard.2018.05.025
3.National Institute of Diabetes and Digestive and Kidney Disesase, Potential Candidates for Bariatric Surgery Who is a good adult candidate for bariatric surgery?, 2016
4.Sawaya RA, Jaffe J, Friedenberg L, Friedenberg FK. Vitamin, mineral, and drug absorption following bariatric surgery. Curr Drug Metab. 2012;;13(9):1345–1355.
5.Christopher M. Bland, April Miller Quidley, Bryan L. Love, Catherine Yeager, Bliss McMichael, P. Brandon Bookstaver, Long-term pharmacotherapy considerations in the bariatric surgery patient, American Journal of Health-System Pharmacy, Volume 73, Issue 16, 15 August 2016, Pages 1230–1242,
6.Menke MN, King WC, White GE, et al. Contraception and Conception After Bariatric Surgery. Obstet Gynecol. 2017;130(5):979–987. doi:10.1097/AOG.0000000000002323
7.Welbourn, R., Hollyman, M., Kinsman, R. et al. OBES SURG (2019) 29: 782. https://doi.org/10.1007/s11695-‐018-‐3593-‐1
8.Management of Patients Receiving, 6th edition Bariatric Surgery, Pharmacotherapy Self-‐Assessment Program
9. Cummings, D.E. & Rubino, F. Diabetologia (2018) 61: 257. https://doi.org/10.1007/s00125-‐017-‐4513-‐y
10. CDC Defining Adult Overweight and Obesity, 2017
11. CDC Obesity and Overweight, 2016
12. CDC Adult Obesity Prevalence Maps, 2019
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Resources
13. American Society for Metabolic and Bariatric Surgery, Bariatric Surgery Procedures
14. NIH National Institute of Diabetes and Digestive and Kidney Disease, Types of Bariatric Surgery
15. El-‐Hadi M, Birch DW, Gill RS, Karmali S. The effect of bariatric surgery on gastroesophageal reflux disease. Can J Surg. 2014;57(2):139–144. doi:10.1503/cjs.030612
16. American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient 2016 Update: Micronutrients
17. Centers for Disease Control and Prevention , U.S. Medical Eligibility Criteria for Contraceptive Use, 2016
18. US Pharm. 2016;41(12):HS2-HS8.
19. Geraldo Mde S, Fonseca FL, Gouveia MR, Feder D. The use of drugs in patients who have undergone bariatric surgery. Int J Gen Med. 2014;7:219–224. Published 2014 May 14. doi:10.2147/IJGM.S55332
20. Robinson SD, Cooper B, Leday TV. Copper deficiency (hypocupremia) and pancytopenia late after gastric bypass surgery. Proc (Bayl Univ Med Cent). 2013;26(4):382–386. doi:10.1080/08998280.2013.11929011
21. Adduci AJ, Phillips CH, Harvin H. Prospective diagnosis of marginal ulceration following Roux-‐en-‐Y gastric bypass with computed tomography. Radiol Case Rep. 2016;10(2):1063. Published 2016 Feb 17. doi:10.2484/rcr.v10i2.1063
22. Stein EM, Silverberg SJ. Bone loss after bariatric surgery: causes, consequences, and management. Lancet Diabetes Endocrinol. 2014;2(2):165–174. doi:10.1016/S2213-‐8587(13)70183-‐9
23. Effect of major gastrointestinal tract surgery on the absorption and efficacy of direct oral anticoagulants (DOACS). J Thromb Thrombolysis. 2017; 43: 343-‐351.
24. Oral anticoagulant use after bariatric surgery: a literature review and clinical guidance. Am J Med. 2017; 130(5): 517-‐524.25. The effect of bariatric surgery on direct-‐acting oral anticoagulant drug levels. Thrombosis Research. 2018;163: 190–195
26. Welbourn, R., Hollyman, M., Kinsman, R. et al. OBES SURG (2019) 29: 782. https://doi.org/10.1007/s11695-‐018-‐3593-‐1
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Resources continued
Bariatric Surgery and Medication Management
Lillian Clark, PharmD, MBAHealth-System Pharmacy Administration PGY2
University of Utah [email protected]
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