At the 2018 annual meeting of the American Association of Clinical Endocrinologists in Boston, Dr. W. Timothy Garvey spoke on strategies for using weight loss medications. Dr. Garvey discussed 4 general principles:
- Why use weight loss medications?
- When should weight loss medications be prescribed?
- What are the therapeutic targets of medication assisted weight loss?
- Which medications should be used?
Why use weight loss medications?
Obesity is a chronic disease that involves interactions among genetic, environmental and behavioral factors. Obesity is treated with medications just like other chronic diseases such as diabetes, hypertension or hyperlipidemia. The regulation of energy intake is mediated by peripheral signals from fat cells, the gastrointestinal tract and the pancreas that act on hypothalamic pathways and higher cortical centers. Obesity medications act along these pathways to decrease appetite and cravings and increase satiety. The addition of a medication for weight loss produces greater weight loss and weight maintenance compared to lifestyle therapy alone.
When should weight loss medications be prescribed?
Weight loss medications are prescribed for patients with a BMI > 30 kg/m2 or with a BMI > 27 kg/m2 if there is a weight-related comorbidity such as hypertension, diabetes or dyslipidemia. Medications should always be used with an effective diet plan.
What are the therapeutic targets of medication assisted weight loss?
Therapeutic targets for weight loss are the reduction of comorbidities. Improvements in type 2 diabetes, hypertension and dyslipidemia can be see with a little as 3-5% weight loss. Where other comorbidities such as fatty liver disease and sleep apnea require 10-15% weight loss to see an improvement.
Which medications should be used?
Currently, there are eight medications approved by the Food and Drug Administration (FDA) for weight loss.
- phentermine (Adipex-P®, Suprenza®)*
- phendimetrazine (Bontril®)*
- benzphetamine (Regimex®, Didrex®)*
- orlistat (Xenical®, alli®)†
- phentermine-topiramate ER (Qsymia®)†
- lorcaserin HCL (BELVIQ®)†
- naltrexone HCl and bupropion HCl (CONTRAVE®)†
- liraglutide injection (Saxenda®)†
*Approved for short term use
†Approved for long term (chronic) use
In selecting the optimal weight loss medication for an individual patient, clinicians should consider differences in efficacy, side effects, cautions, warnings and drug interactions along with the patient’s medical history. These factors are the basis for individualized weight loss therapy.