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The Principles of Pharmacology

For appropriate patients, pharmacological treatments are part of a comprehensive approach to long-term weight management.

Three guiding principles should be followed when considering pharmacotherapy for patients with obesity1

Reinforce patient efforts

Pharmacotherapy is meant to reinforce patient lifestyle efforts, not replace them.

Understand side effects

Health care professionals and patients should both be familiar with the medication and its potential side effects and contraindications.

Every patient is different

If clinically meaningful weight loss (≥5%) is not achieved after 3-4 months, a new treatment plan should be implemented.

Most patients living with obesity are not able to achieve and maintain a healthy weight with healthy eating and increased activity alone2

Some pharmacological treatments may benefit patients who:

Have tried lifestyle changes but can’t reach a healthier weight

  • Have tried lifestyle changes but can’t reach a healthier weight

Are regaining weight after losing it

  • Are regaining weight after losing it

Have a BMI of ≥27 kg/m2 and a weight-related comorbidity

  • Have a BMI of ≥27 kg/m2 and a weight-related comorbidity

Have a BMI that is >30 kg/m2

  • Have a BMI that is >30 kg/m2

Different pharmacological medications may help the patient to lower appetite, increase energy expenditure, decrease the amount of fat the body absorbs, or reduce cravings.2,3

Patient with obesity being physically active

Treatment plans that include pharmacotherapy, as an adjunct to healthy eating and increased physical activity, may be more effective than any of those alone4

From a 1-year study of 224 patients with BMI of 30 to 45 kg/m2

Graph comparing weight loss in patients who received combined therapy (medication with lifestyle counseling) versus other treatment groups from a 1-year study
Graph comparing weight loss in patients who received combined therapy (medication with lifestyle counseling) versus other treatment groups from a 1-year study

Significant weight loss

Patients who received combined therapy (medication with lifestyle counseling) lost significantly more weight at weeks 18, 40, and 52 than all other treatment groups (P<0.001).4

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From a 1-year study of 224 patients with BMI of 30 to 45 kg/m2, randomly assigned to receive medication (sibutramine) alone, lifestyle modification with brief therapy, or medication with lifestyle-modification counseling (combined therapy).4

Study design

From a 1-year study of 224 patients with BMI of 30 to 45 kg/m2, randomly assigned to receive medication (sibutramine) alone, lifestyle-modification counseling, or medication with lifestyle-modification counseling (combined therapy).4

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A total weight-management plan

Patients' weight history

1. Bray GA, Fruhbeck G, Ryan DH, Wilding JPH. Management of obesity. Lancet. 2016;387(10031):1947-1956.

2. Garvey WT, Mechanick JI, Brett EM, et al; and Reviewers of the AACE/ACE Obesity Clinical Practice Guidelines. American Association of Clinical Endocrinologists and American College of Endocrinology comprehensive clinical practice guidelines for medical care of patients with obesity. Endocr Pract. 2016;22(suppl 3):1-203.

3. Kim GW, Lin JE, Blomain ES, et al. Antiobesity pharmacotherapy: new drugs and emerging targets. Clin Pharmacol Ther. 2014;95(1):53-66.

4. Wadden TA, Berkowitz RI, Womble LG, et al. Randomized trial of lifestyle modification and pharmacotherapy for obesity. N Engl J Med. 2005;353(20):2111-2120.