Weight loss drugs and bariatric surgery Flashcards
Phentermine
Cheapest weight loss drug!!
Prescribed in the US for weight loss since the 1960’s
Increases brain norepinephrine levels (acts centrally to increase satiety and thereby reduce food intake)
Available as generic=cheaper
Currently the most widely prescribed weight loss drug on the market
Average weight loss provided is roughly 5% of baseline weight
Side effects: Nervousness, difficulty sleeping, headache and dry mouth. The concerning side effect is an increase in blood pressure that occurs in roughly 1-2% of people taking the drug.
Contraindicated in pts with HTN
Orlistat
Safest weight loss drug!!
Pancreatic lipase inhibitor that blocks dietary fat absorption from the GI tract (blocks 1/3 of dietary fat absorption)
Average weight loss provided is roughly 5% of baseline weight
Side effects: No systemic side effects. The primary side effects relate to its mechanism of action: oily stools, a sense of urgency, some diarrhea or oily leakage. A theoretical side effect is deficiency of fat soluble vitamins (so take a multivitamin)
There are important drug interactions with Coumadin (increased INR) and cyclosporine (reduced drug levels).
Lorcasarin
selective serotonin 2C receptor agonist (only in brain and not heart)
4-5 % weight loss and no evidence of cardiac valve problems in patients followed out to 2 years of exposure to the drug
Least side effects!
Phetermine/topiramate
Most effective
Combination product (greater weight loss, less side effects)
Topiramate has teratogenic potential and its use needs to be carefully controlled in women of reproductive age.
Lose 10-12% of baseline weight
Side effects: dry mouth, paresthesias, insomnia, dizziness, anxiety, irritability and disturbance in attention
Naltrexone SR/Bupropion SR
Combination of the opioid receptor antagonist naltrexone with the dopamine and norepinephrine reuptake inhibitor bupropion
weight loss is about 5%
“black box warning” about a risk of increase suicidal ideation
The serious but uncommon risks are: suicidal ideation, lowering seizure threshold, increased pulse and blood pressure, and rarely increased liver function tests and closed angle glaucoma.
Category X in pregnancy
What are the 3 commonly performed weight loss operations?
Roux en Y gastric bypass (RYGB) operation, the laparascopic band procedure, and sleeve gastrectomy
What is the amount of weight loss associated with each surgical procedure?
Lap band: 20-24% weight loss
Sleeve: 24-27% weight loss
RYGB: 28-30% weight loss
Risks of RYGB
Risk of death 0.7% in 30 days
Thromboembolic disease, a leak from a staple line, pneumonia or a wound infection
Risk of nutritional deficiencies including niacin deficiency, B12 deficiency, vitamin D deficiency with resultant metabolic bone disease and iron deficiency especially in menstruating women
No getting preggo for a year
Risk from sleeve or lap band
lower than RYGB
Benefits of RYGB
In randomized controlled trials more than 40% of those individuals with type 2 diabetes pre-operatively will have resolution of their diabetes post-operatively following a RYGB
Benefits in sleep apnea, gastroesophageal reflux, degenerative arthritis, weight related infertility, hypertension and even reducing the risk of cancer. Several studies now provide evidence of a long term mortality benefit to bariatric surgery.
Benefits of sleeve and band
The sleeve gastrectomy has almost as dramatic an effect as RYGB.
Lap band is not quite a beneficial but it also has been shown to be superior to standard medical therapy in controlling glucose levels in people with type 2 diabetes.
Benefits in sleep apnea, gastroesophageal reflux, degenerative arthritis, weight related infertility, hypertension and even reducing the risk of cancer. Several studies now provide evidence of a long term mortality benefit to bariatric surgery.
Who qualifies for medical therapy for weight loss?
BMI>30 kg/m2 in the absence of medical conditions or a BMI>27 kg/m2 and weight related co-morbid health conditions like diabetes, hypertension, sleep apnea or degenerative arthritis
Who qualifies for surgery for weight loss?
BMI>40 kg/m2 in the absence of medical conditions or a BMI>35 kg/m2 and weight related co-morbid health condition
Thiamine deficiency risk
One of the most serious vitamin deficiencies that can occur following surgery and can result in Wernike Korsakoff syndrome (double vision, ataxia, altered mental status) that can progress to severe disability and even death if not diagnosed and treated.
