Phentermine
Phentermine alone is only approved for those older than 16 years who have a BMI of at least 30, or at least 27 with weight-related comorbidities, and it’s not approved for use longer than 12 weeks. It results in a BMI change of up to 5%. It should be considered in those with strong hunger and low energy and in those who don’t have adequate insurance coverage because out-of-pocket costs can be as little as $5/mo.
Contraindications are the same as those for the combined pill above: Substance use, cardiovascular disease, hyperthyroidism, glaucoma, MAOI use, and agitation. Again, take caution with patients who have hypertension, have congenital heart disease, or take SSRIs or insulin.
Side effects can include palpitations, tachycardia, dry mouth, headache, insomnia, and anxiety. The dose starts at 15 mg daily, and Fox advises following a similar follow-up as with the other medications, at which clinicians should assess BMI, the medication’s effect on eating, cardiovascular health, and side effects and have a discussion about off-label use. Off-label use refers to prescriptions lasting longer than 12 weeks, but it’s arguably safer than attention-deficit/hyperactivity disorder stimulants because of the lower addiction potential, Fox said.
What Else to Know
Because obesity is a chronic disease, treatment will be ongoing, Fox noted. A lot of people will ask when or where the “off-ramp” for these medications is, but many people will need these medications long term just as someone with other chronic diseases requires lifetime pharmacotherapy. The treatment intensity will vary based on disease severity and individual characteristics, Fox said.
For those feeling overwhelmed by the options, Fox advises clinicians to start by picking one medication to learn and then spending the time to read the FDA package insert in full. Get samples and then closely follow patients to learn that medication well before moving on to learn another. She also noted the opportunity for pediatricians to see a pediatric obesity medicine fellowship.
No external funding was used for the presentation. Fox is a site principal investigator for clinical trials sponsored by Novo Nordisk and Eli Lilly. Ivers had no disclosures.
A version of this article first appeared on Medscape.com.