What are good choices for this patient?
Lorcaserin is a good choice for this patient who is overweight and has several weight-related comorbidities. She has worked hard to lose a significant number of pounds and is now at high risk of regaining them. That’s because her appetite has increased with her new exercise regimen, but her energy expenditure has decreased secondary to metabolic adaptation.
Narrowing the field. Naltrexone SR/bupropion SR cannot be used because of her opioid use. Phentermine/topiramate ER is contraindicated for patients with glaucoma, and liraglutide 3 mg is not appropriate given the patient’s fear of needles.
She could try orlistat, especially if she struggles with constipation, but the gastrointestinal adverse effects are difficult for many patients to tolerate. While not an antiobesity medication, a sodium-glucose co-transporter 2 (SGLT2) inhibitor could be prescribed for her diabetes and also may promote weight loss.43
An appealing choice. The glucose-lowering effect of lorcaserin could provide an added benefit for the patient. The BLOOMDM (Behavioral modification and lorcaserin for overweight and obesity management in diabetes mellitus) study reported a mean reduction in hemoglobin A1c of 0.9% in the treatment group compared with a 0.4% reduction in the placebo group,30 and the effect of lorcaserin on A1c appeared to be independent of weight loss.
Mechanism of action: Cause for concern? Although lorcaserin selectively binds to serotonin 5-HT2C receptors, the theoretical risk of cardiac valvulopathy was evaluated in phase III studies, as fenfluramine, a 5-HT2B-receptor agonist, was withdrawn from the US market in 1997 for this reason.44 Both the BLOOM (Behavioral modification and lorcaserin for overweight and obesity management) and BLOSSOM (Behavioral modification and lorcaserin second study for obesity management) studies found that lorcaserin did not increase the incidence of FDA-defined cardiac valvulopathy.28,29
Formulations/adverse effects. Lorcaserin is available in 2 formulations: 10-mg tablets, which are taken twice daily, or 20-mg XR tablets, which are taken once daily. Both are generally well tolerated.27,45 The most common adverse event reported in phase III trials was headache.28,30,43 Discontinue lorcaserin if the patient does not lose 5% of her initial weight after 12 weeks, as weight loss at this stage is a good predictor of longer-term success.46
Some patients don’t respond. Interestingly, a subset of patients do not respond to lorcaserin. The most likely explanation for different responses to the medication is that there are many causes of obesity, only some of which respond to 5-HT2C agonism. Currently, we do not perform pharmacogenomics testing before prescribing lorcaserin, but perhaps an inexpensive test to identify responders will be available in the future.
CASE 3 A preoccupation with food
A 38-year-old woman with obesity (BMI 42 kg/m2),obstructive sleep apnea, gastroesophageal reflux disease, and depression is eager to get better control over her weight. Her medications include lansoprazole 30 mg/d and a multivitamin. She reports constantly thinking about food and not being able to control her impulses to buy large quantities of unhealthy snacks. She is so preoccupied by thoughts of food that she has difficulty concentrating at work.
The patient smokes a quarter of a pack of cigarettes daily, but she is ready to quit. She views bariatric surgery as a “last resort” and has no anxiety, pain, or history of seizures. Which medication is appropriate for this patient?