Weight loss medication guide

Pharmacotherapy (and other interventions) for Obesity and Weight Loss: a Resident’s Guide to Who, When, Why and How!

Gabriela Aviles, MD, MPH

Updated: February 2022

General Principles

1. Why we care: Per the most recent NHANES data (2017-2018) 42.4% of all adults have obesity, and around 30.7% of all adults are overweight. This is a chronic disease that is linked to a myriad of COMORBIDITIES, such as HTN, insulin resistance, dyslipidemia, OSA and an INCREASED RISK OF MORTALITY from CV disease, diabetes, kidney disease, and certain types of cancer (including colon, breast, uterine, pancreatic).

2. LIFESTYLE HABITS are the cornerstone of all obesity treatments. Remember the basics on lifestyle habits to help promote sustained weight loss (just a brief overview, I promise!):

- Healthy eating habits= THE most important thing for weight management! General rules of thumb include avoiding processed foods, eating lots of plants, and using water as the primary source of hydration. The eating plans with the most evidence for health and weight loss are WHOLE FOOD, PLANT-BASED DIET or MEDITERRANEAN DIET

o Nifty resources! Brief Look at the Mediterranean diet via AHA: https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/nutrition-basics/mediterranean-diet

o In case you want to learn more about living that plant-based lifestyle: Forks over knives (one of several WFPB plans out there)- has free recipes, sample eating plans, and a beginner’s guide https://www.forksoverknives.com/

- Exercise: minimum goal is 150 MINUTES/WK of MODERATE physical activity

o More nifty resources! Exercise is Medicine Website- lots of info on how to prescribe physical activity to your patients, with considerations on different comorbidities and how this impacts exercise. https://www.exerciseismedicine.org/eim-in-action/health-care/health-care-providers/

- Behavioral counseling can help patients identify eating habits, current triggers, etc. Consider INTENSIVE BEHAVIORAL THERAPY (defined as 14+ sessions in 6 months, with a trained professional, group OR individual) for weight loss

3. Believe it or not, medication for weight loss is not always a hard “NO”. there are some circumstances where you should consider this for your patients! * That being said, remember: Pharmacotherapy is IN ADDITION TO not INSTEAD OF lifestyle modifications.

- *When to Consider the Weight Loss Meds: For patients who have tried lifestyle measures as above AND have BMI >30 OR BMI >27 PLUS other comorbidities (HTN, T2DM, OSA, hyperlipidemia, etc)

4. If <5% weight loss occurs after 3 months, implement a new treatment plan. If responds adequately to therapy (that is >5% WEIGHT LOSS IN 3 MONTHS), may continue with pharmacotherapy

5. Choice of pharmacotherapy is based on the individual risk/benefit profile for the patient

- What other medications are they already on? Potential drug-drug interactions?

- Presence of other comorbidities? HTN, DM, heart disease

SEE TABLE 1 BELOW

Table 1 notes:

- According to a recent Lancet Systematic Review and meta-analysis, PHENTERMINE-TOPIRAMATE and GLP-1 AGONISTS (especially SEMAGLUTIDE) appear to be the most effective medications for weight loss

- PHENTERMINE-TOPIRAMATE and NALTREXONE-BUPROION were associated with highest risk for adverse events

A Brief Overview on Surgical Management of Weight Loss (AKA- BARIATRIC SURGERY)

- When to consider it: BMI >40 OR BMI >35 PLUS comorbidity

- Patients need to undergo behavioral counseling/psychiatric evaluation to determine if they would be a good candidate for this intervention- not only is surgery an invasive and physically taxing procedure, successful post-operative course requires that these patients change how they eat long-term

- Types of Bariatric Surgery:

o Roux en Y: malabsorptive AND restrictive; jejunum connected to proximal part of stomach, bypassing most of distal stomach, expect 30-40kg weight loss in 10 years

o Biliopancreatic diversion +/- duodenal switch: malabsorptive AND restrictive; small intestine rearranged to separate food from flow of bile and pancreatic juices, interacting only with last 18-24 in of intestine, often combined with gastric stapling or bypass.

o Gastric banding: restrictive; prosthetic band placed at stomach entrance restricting proximal stomach; 20-30 kg weight loss x5 years; up to 75% lap bands removed due to lack of weight loss.

o Sleeve gastrectomy: restrictive; removal of ~75% stomach, 30-40 kg weight loss x5 years

o Vertical-banded gastroplasty: restrictive; upper stomach near esophagus stapled vertically creating small pouch along inner curve of stomach, outlet restricted with band which delays food emptying

- Post-Bariatric Surgery Care and Monitoring: focus on long-term recommendations and monitoring in the outpatient setting (I recommend looking at other resources if you want to know more about the immediate post-op care)

o Nutrition: consult a dietitian/specialist to assess patient and provide recommendations. specific recommendations depend on the type of surgical procedure performed. Generally, patients should be counseled to:

§ Have 3 small meals daily, chewing small bites of food

§ Consume fluids slowly, at least 30 min after meals

§ 5+ daily servings of Fresh fruits and vegetables

§ Recommended protein intake >60 g/d up to 1.5-2 g/kg ideal BW

§ Eliminate concentrated sweets from diet to reduce caloric intake and minimize dumping syndrome s/p Roux-en-Y

o Supplements: to replace micronutrient deficiencies

§ 2 adult multivitamins + minerals (chewable for first 3-6 mo)

· Thiamine (12 mg)

· Folic acid (400-800 mcg)

· Iron (18-60 mg)

§ Elemental Ca 1200-1500 mg (for sleeve gastrectomy or Roux-en-Y) OR 1800-2400 mg for biliopancreatic diversion

§ Vit D 2000-3000 IU titrated to 25-OH D level >30

§ Zinc 8-22 mg

§ Copper 2 mg

§ Vit B12 as needed to maintain levels

o Labs to Monitor:

§ Iron studies: once in first 3 months after surgery, then every 3-6 months in first year after surgery, then annually

§ B12: baseline, then every 3 months in year 1, then annually. Consider checking MMA and homocysteine levels, too.

§ Vit A: in year 1 after Roux-en-Y or biliopancreatic diversion

§ Vit D: check baseline postoperatively, then annually after Roux-en-Y, sleeve gastrectomy, or biliopancreatic diversion

§ Thiamine: consider in patients at risk for deficiency (women, protracted vomiting/GI symptoms)

§ Zinc: consider in patients with symptoms (chronic diarrhea, hair loss, pica) after Roux-en-Y gastric bypass or biliopancreatic diversion with or without duodenal switch

§ Copper: consider copper and ceruloplasmin annually in patients with Roux-en-Y gastric bypass or biliopancreatic diversion with or without duodenal switch

§ Selenium: consider checking if unexplained anemia, fatigue, persistent diarrhea, metabolic bone disease following malabsorptive surgery

o Medication Considerations:

§ In first 2 months after surgery, PO meds should be liquid (caution on fructose/lactose content) OR consider alternate routes of administration

§ Patients might require less antihypertensives, meds for BG control (D/C SULFONYLUREAS, MEGLITINIDES, MEAL-TIME INSULIN, DECREASE BASAL INSULIN BY 50-75%)

§ Medications/substances to avoid after bariatric surgery:

· Bisphosphonates: increased risk of upper GI irritation

· ETOH: especially after Roux-en-Y, increase rate of absorption

· NSAIDS: increased risk of gastric injury, consider PPIs if used

· Oral contraceptives: *WOMEN SHOULD AVOID PREGNANCY 12-18 MONTHS AFTER SURGERY* after malabsorptive procedures, recommend avoiding progesterone-only pills and combined OCPs due to decreased efficacy; OK to use any hormonal contraceptive with restrictive procedures

Resources:

1. Kane, Michael P, Minze, Molly G. Endocrine Disorders. ACCP/ASHP Ambulatory Care Pharmacy Preparatory Review and Recertification Course 2021; 75-87.

2. Shi Q, Wang Y, Hao Q, et al. Pharmacotherapy for Adults with Overweight and Obesity: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials. Lancet 2022; 399: 259-269

3. Clinical Resource, Weight Loss Products. Pharmacist’s/Letter/ Prescriber’s Letter. August 2021.

4. Clinical Resource, Bariatric Surgery and Medication Use. Pharmacist’s Letter/Prescriber’s Letter. March 2018.

5. DynaMed. Bariatric Surgery in Adults. EBSCO Information Services. Accessed February 4, 2022. https://www.dynamed.com/procedure/bariatric-surgery-in-adults