Weight loss

Overweight

BMI 25 - 29.9 kg/m2

Obese

BMI ≥ 30 kg/m2

Overweight people are at higher risk for

coronary heart disease, HTN, stroke, T2DM

Energy deficit

- calories must be decreased and/or energy expenditure increased in order to lose weight (force body to use fat as an energy source)

Satiety

feeling of fullness

Select drugs/conditions that can cause weight gain

- antipsychotics (clozapine, olanzapine, risperidone, quetiapine)

- DM drugs (insulin, sulfonylureas, meglitinides, thiazolidinediones)

- divalproex / valproic acid

- gabapentin, pregabalin

- lithium

- mirtazapine

- steroids

- TCAs (amitriptyline, nortriptyline)

- conditions: hypothyroidism

Other drugs that can cause weight gain

- BB

- dronabinol

- hormones (estrogen, megestrol)

- MAO inhibitors

- SSRIs (paroxetine, others may be weight neutral)

- vasodilators (minoxidil)

Physical activity should increase to

≥ 150 minutes per week, performed on 3 to 5 separate days

When to start weight loss meds

- when lifestyle measures alone have failed to achieve adequate weight loss, maintain weight loss or prevent continued weight gain

- start at the same time as lifestyle measures in patients with weight-related complications

OTC supplements for weight loss

- bitter orange

- caffeine (yerba mate, guarana, concentrated green tea powder)

- not recommended due to efficacy & potential harm especially in CVD patients

Prescription weight loss meds

- NOT appropriate for patients with small amounts of weight to lose

- indicated for BMI ≥ 30 kg/m2 or a BMI ≥ 27 kg/m2 with at least one weight-related condition (DLD, HTN, DM)

- only used in addition to a dietary plan and increased physical activity

Long term newer prescription drugs for weight loss

- Qsymia, Contrave, Saxenda, Wegovy, Zepbound, orlistat

Weight loss drugs should be dc if they do not produce at least a

5% weight loss at 12 weeks

Select drugs/conditions that can cause weight loss

- ADHD drugs (amphetamine, methylphenidate)

- acetylcholinesterase inhibitors (donepezil, rivastigmine, galantamine)

- antiseizure meds (zonisamide, ethosuximide)

- bupropion

- interferons

- GLP-1 agonists (exenatide, liraglutide)

- pramlintide

- roflumilast

- SGLT-2 inhibitors (canagliflozin, empagliflozin)

- topiramate

- tirzepatide

- thyroid drugs (levothyroxine)

- conditions: hyperthyroidism, celiac disease, IBS, cystic fibrosis, GERD/PUD, lupus, active TB

Which weight loss meds to avoid/use caution in pregnant patients

avoid all weight loss drugs

Which weight loss meds to avoid/use caution in HTN

- avoid: Contrave (contains bupropion), stimulants (ex.phentermine) - CI in uncontrolled BP

- Caution: Qsymia - mx HR (contains phentermine)

Which weight loss meds to avoid/use caution in depression

- caution in young adults/adolescents

- Contrave: suicide risk (contains buproprion)

Which weight loss meds to avoid/use caution in seizures

- avoid: Contrave - lowers seizure threshold (contains bupropion)

- caution: Qsymia - must taper off slowly if used (contains topiramate)

Which weight loss meds to avoid/use caution in patients taking opioids

- avoid: Contrave - blocks opioid receptors (contains naltrexone)

Phentermine

- sympathomimetic (stimulant); release of norepinephrine stimulates the satiety center = lowers appetite

Topiramate

- increases satiety and reduces appetite, possibly by increasing GABA, blocking glutamate receptors &/or inhibition of carbonic anhydrase

Qsymia

- Phentermine/Topiramate ER

- C-IV

- REMS: teratogenic (pregnancy test + contraception required)

Qsymia (Phentermine/Topiramate ER)

- CI: pregnancy, glaucoma

- SE: tachycardia, CNS effects (insomnia) (take in the morning to reduce risk), vision problems

- taper off due to seizure risk

- reduced renal dose

- titrate dose up based on wt loss; PO QAM

Naltrexone

reduce food cravings

Buproprion

reduce appetite

Contrave (naltrexone/bupropion)

- ER tablet

- PO QAM; titrate weekly as tolerated to BID

- fatty foods increases drug lvls: do NOT take with high-fat meal

- do not chew, cut, crush; swallow whole

- CI: pregnancy, opioid use, uncontrolled HTN, seizure disorder, use of other buproprion-containing products, use of MAO inhibitors w/in 14 days

- warnings: use caution w/ psychiatric disorders

Naltrexone blocks opioids and buprenorphine; how many days prior to starting Contrave should you dc opioids/buprenirphine?

7-14 days before initiating Contrave

Glucagon-Like Peptide 1 (GLP-1) Agonists

- increase satiety

- liraglutide, semaglutide

Liraglutide (Saxenda)

- GLP-1 agonist injection

- DM: Victoza

- start: 0.6 mg SC daily x 1 week; titrate up by 0.6 mg SC daily ay weekly intervals

- target dose: 3 mg SC daily

- CI: pregnancy

Semaglutide (Wegovy)

- GLP-1 agonist injection

- DM: Ozempic (SC) and Rybelsus (PO)

- start: 0.25 mg SC weekly x 4 weeks; titrate up every 4 weeks

- target dose: 2.4 mg SC weekly, or 1.7 mg SC weekly (if 2.4 mg is untolerated)

Dual GLP-1 and Glucose-Dependent Insulinotropic Polypeptide (GIP) Agonists

- increase satiety

- Tirzepatide

Tirzepatide (Zepbound)

- GLP-1 agonist + GIP agonist injection

- DM: Mounjaro

- start: 2.5 mg SC weekly x 4 weeks, then increase to 5 mg SC weekly

- can increase to 15 mg SC weekly

- SE: increased HR

GLP-1 agonist/ GIP agonist Warnings

- pancreatitis, hypoglycemia, AKI, gallbladder disease

- NOT recommended in patients with severe GI disease, including gastroparesis

GLP-1 agonist/ GIP agonist SE

nausea (primary SE), V/D, constipation, hypoglycemia, injection site rxns

GLP-1 agonist/ GIP agonist Notes

- may need to reduce insulin or sulfonylurea/meglitinide doses to reduce risk of hypoglycemia

- can reduce the absorption of orally administered drugs dt reduced gastric emptying (caution w/ abx, OCPs)

Lipase Inhibitor

- reduce absorption of dietary fats by ~30%

- Orlistat

Orlistat

- Rx: Xenical - 120 mg PO w/ each meal containing fat; take with meal or up to 1 hr after eating

- OTC: Alli - 60 mg PO w/each meal containing fat

- must be used with a low-fat diet

- CI: pregnancy, cholestasis

- Warnings: liver damage

- SE: GI (flatus w/ discharge, fatty stools)

- take multivitamin (A, D, E, K, beta-carotene) at bedtime or separated by 2 hours

- max 30% of kcals from fat

Appetite suppressants

- sympathomimetics (stimulants), release of norepinephrine stimulates the satiety center which reduces appetite

- phentermine, diethylpropion, phendimetrazine, benzphentamine

Appetite suppressants (phentermine, diethylpropion, phendimetrazine, benzphentamine)

- CI: CVD (uncontrolled HTN, pulmonary HTN), hyperthyroidism, glaucoma, pregnancy, hx of drug abuse

- SE: tachycardia, agitation, increased BP, pulmonary HTN (use > 3 mons), insomnia

- Mx: HR, BP, sx of pulmonary HTN (dyspnea/SOB)

- only for short term use, up to 12 weeks

Bariatric surgery indicated for

- BMI ≥ 35 kg/m2

- BMI ≥ 30 kg/m2 with T2DM

- BMI ≥ 30 kg/m2 who cannot achieve or sustain a goal BMI or improvement in an obesity-related comorbidity with other methods

Complications of bariatric surgery

- nutrient deficiencies

- medication concerns

common nutrient deficiencies

- Ca: calcium citrate supplementation is preferred as it has non-acid dependent absorption

- Vitamin B12 deficiency &/or iron deficiency = anemia; both may require supplementation

- Iron & Ca supplements should be taken 2 hours prior or 4 hours after antacids

- may require life-long supplementation of fat-soluble vitamins (A, D, E, K) dt fat malabsorption

Medication concerns with bariatric surgery

- meds may require dose reduction and may need to be crushed & put in liquid or used in transdermal form for up to 2 months post-surgery

- rapid wt loss can cause gallstones. Ursodiol dissolves gallstones and may be needed