Obesity Treatment: Drugs, Surgical Options and Popular Diets Flashcards Preview

DEMS: Unit IIb > Obesity Treatment: Drugs, Surgical Options and Popular Diets > Flashcards

Flashcards in Obesity Treatment: Drugs, Surgical Options and Popular Diets Deck (19)
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Medications available for treatment of obesity (5)

  • Phentermine
  • Orlistat (Rx: Xenical, OTC: Alli)
  • Lorcasarin (Belviq)
  • Phentermine/topiramate (Qsymia)
  • Naltrexone SR/Bupropion SR (Contrave)


Phentermine: MOA

  • Increases NE content in brain
  • Chemically related to amphetamine
  • Non-addictive stimulant


Phentermine: side effects

  • Hypertension
  • Headache
  • Nervousness
  • Sleep disturbance
  • No evidence of serious SE when used as monotherapy --> most widely prescribed
  • FDA approved for 3-month use
  • Not approved for long-term use (no one willing to fund long-term studies)


Orlistat: MOA

  • Pancreatic lipase inhibitor
  • Inhibits fat absorption by 30%


Orlistat: side effects

  • GI side effects: oily stools, urgency, flatulence (spray farts?!)
  • Need multivitamin to prevent fat soluble vitamin deficiency
  • DDIs: coumadin and cyclosporin (decrease drug levels)
  • Limited use: increased cost, limited weight loss, no insurance coverage


Lorcasarin (Belviq): MOA

  • Recently FDA approved
  • Selective serotonin 2C receptor agonist
  • 2C receptors found only in brain (not on heart, will not cause cardiac toxicity like old serotonin weight loss drugs)
  • Produce 4-5% weight loss


Lorcasarin (Belviq): side effects

  • No evidence of cardiac toxicity in patients followed out to 2 years
  • Question: will it have similar level of efficacy to phen/fen (12-15% weight loss) without the cardiac side effects? No data yet.
  • Costs $220-250/month


Phentermine/topiramate (Qsymia): MOA

  • Phentermine: sympathomimetic, exact MOA unknown, stimulates CNS activity
  • Topiramate: blocks voltage-dependent sodium channels, augments GABA activity, antagonizes glutamate receptrs, inhibits carbonic anhydrase
  • Combo drug like beta blocker/vasodilator used to treat hypertension
  • Substantially more weight loss than with other medications: 10-12% of baseline weight


Phentermine/topiramate (Qysmia): side effects

  • Concerns that topiramate has teratogenic potential
  • Use needs to be carefully controlled in women of reproductive age
  • Negative pregnancy test before starting medication, pregnancy test documented monthly
  • Side effects:
    • Dry mouth
    • Paresthesias
    • Insomnia
    • Dizziness
    • Anxiety
    • Irritability
    • Disturbance in attention


Naltrexone SR/Bupropion SR (Contrave): MOA

  • Newest weight loss medication
  • Naltrexone: opioid receptor antagonist
  • Bupropion: Dopamine/NE reuptake inhibitor
  • Average weight loss ~5% of baseline
    • More effective than phentermine, locasarin
    • Less effective than phentermine/topiramate
  • Also used as smoking cessation aid and antidepressant


Naltrexone SR/Bupropion SR (Contrave): side effects

  • Black box warning: risk of increased suicidal ideation
  • Serious but uncommon risks: 
    • Suicidal ideation
    • Lowering seizure threshold
    • Increased pulse and blood pressure
    • Rarely: increased LFTs, closed angle glaucoma


Drugs used for other problems that can contribute to weight gain

  • Birth control pills, Depo-Provera (shot)
  • Anti-diabetics: sulfonylureas, insulin, TZD
  • Mood stabilizers, anti-psychotics
  • Glucocorticoids (e.g. prednisone)


How to minimize weight gain effects of other drugs

  • Monitor weight/lifestyle changes
  • Choose a different drug
  • Lower dose
  • Weigh risks and benefits of medication


Alternate drugs with weight loss as side effect (2)

  • Bupropion
    • Some evidence for slow weight loss
    • If on other anti-depressant, can talk to psychiatrist about a possible switch for weight loss benefit
  • Topiramate
    • Anti-seizure with weight loss SE at higher doses
    • With big dose: 10-12% weight loss
  • Neither approved on their own for weight loss


Benefits of bariatric surgery

  • Weight loss roughly
    • Gastric bypass: 30% (50-60% of excess weight), maintained for > 15 years
    • Laparoscopic banding: 20-25%, decreased risk
  • Sleep apnea: improved in almost all
  • Hypertension: improved in 50%
  • GERD: improved in most
  • Urinary incontinence: improved in most
  • Cancer deaths: decreased by 50%
  • Great at reducing diabetes-related death
  • 83% won't need to take diabetes medications anymore
  • Great at reducing death from CVD


Risks of bariatric surgery

  • Bypass: death rate = 0.7% within 30 days, 2-3% within 2 years
  • Lap band: death rate = 0.1%
  • Failure of surgery to produce weight loss: 10-15%
  • Pulmonary embolism
  • Anastomotic leaks and sepsis
  • Wound infections and dehiscence (wound breaks open along suture)
  • Anastomotic stricture: dilatation or re-operate
  • Thiamine deficiency: early vomiting, Wernicke-Korsakoff psychosis


Late risks of bariatric surgery

  • Diarrhea, vomiting: dietary indiscretion (sign of poor outcome)
  • Vomiting without diarrhea: consider stricture
    • UGI vs. endoscopy --> may respond to dilation
  • Anastomotic ulcer: Fe+ deficiency anemia or bleeding
  • Depression: 20% may last 3-6 months
  • Protein calorie malnutrition: more common with malabsorptive procedures
  • Folate deficiency: one prenatal vitamin/day
  • B12 deficiency: 30% complication rate 1-9 years post-op
  • Fe2+ deficiency: increased in menstruating women


Characteristics of good candidate for bariatric surgery

  • BMI > 35 with comorbidities
  • OR BMI > 40 without comorbidities
  • Comorbidities: diabetes, sleep apnea, reflux > hypertension, degenerative joint disease
  • Age 20-60, some teenagers are candidates
  • Family history of comorbidities
  • Other failed therapy
  • No serious, active cardiac, pulmonary, or psychiatric disease


Characteristics of good candidate for pharmacotherapy

  • BMI > 27 with comorbidities
  • OR BMI > 30 without comorbidities