MKSAP quiz: Weight loss treatment

This month's quiz asks readers to evaluate a 49-year-old woman who is overweight, has hypertension and type 2 diabetes mellitus, and has attempted to lose weight through multiple methods.


A 49-year-old woman is evaluated during a follow-up visit. She is overweight and has hypertension and type 2 diabetes mellitus, both of which are well controlled. For several years, she has attempted to lose weight through various commercial diets; dietician-monitored, calorie-restricted diets; and physical activity. She has worked with a behavioral therapist, and although she has not achieved weight loss, her weight has remained stable. She exercises 30 minutes daily. Medical history is also remarkable for glaucoma, generalized anxiety disorder, and chronic constipation. Medications are lisinopril, metformin, timolol eye drops, and sertraline.

On physical examination, temperature is normal, blood pressure is 128/74 mm Hg, pulse rate is 70/min, and respiration rate is 12/min. BMI is 29. Waist circumference is 92 cm (36 in). Head, neck, lung, and heart examinations are normal. The abdomen is obese without striae.

In addition to continuing calorie restriction and exercise, which of the following is the most appropriate management to help this patient achieve weight loss?

A. Lorcaserin
B. Orlistat
C. Phentermine-topiramate
D. Roux-en-Y gastric bypass


MKSAP Answer and Critique

The correct answer is B. Orlistat. This item is available to MKSAP 17 subscribers as item 14 in the General Internal Medicine section. More information about MKSAP 17 is available online.

The most appropriate management is to treat this overweight patient with orlistat. Pharmacologic therapy may be used as an adjunct to diet, physical activity, and behavioral treatments in patients with a BMI of 30 or higher or in patients with a BMI of 27 or higher with overweight- or obesity-associated comorbidities. In light of this patient's dieting attempts (including with dietician-monitored diets), physical activity, and behavioral therapy without sustained weight loss, she should be considered for pharmacologic treatment, and the most appropriate pharmacologic agent for this patient is orlistat. Orlistat is an inhibitor of gastric and pancreatic lipases. Taken three times per day (during or up to 1 hour after meals), orlistat results in malabsorption of approximately 30% of ingested fat. Twelve months of orlistat treatment at doses of 120 mg three times per day or 60 mg (available over the counter) three times per day results in a mean weight loss of 3.4 kg or 2.5 kg (7.5 lb or 5.5 lb), respectively, compared with placebo. Orlistat also reduces BMI, waist circumference, blood pressure, blood cholesterol level, and risk for type 2 diabetes mellitus. Loose stool is a common side effect of orlistat; however, this may not be a major concern for this patient given her chronic constipation.

Lorcaserin, a brain serotonin 2C receptor agonist, acts as an appetite suppressant. It should be used with caution in patients taking medications that increase serotonin levels, such as sertraline. Therefore, this patient should not be prescribed lorcaserin.

Combination low-dose phentermine (a sympathomimetic drug) and low-dose topiramate (an antiepileptic drug) has demonstrated efficacy in reducing weight, possibly by suppressing appetite, altering taste, and increasing metabolism. However, phentermine-topiramate is contraindicated in patients with glaucoma; thus, it should not be prescribed in this patient.

Referral for bariatric surgery is indicated in all patients with a BMI of 40 or higher and in patients with a BMI of 35 or higher with obesity-related comorbid conditions. This patient does not meet the criteria for bariatric surgery.

Key Point

  • Pharmacologic therapy may be used as an adjunct to diet, physical activity, and behavioral treatments in patients with a BMI of 30 or higher or in patients with a BMI of 27 or higher with overweight- or obesity-associated comorbidities.