Obesity Medication Update
Common questions from my patients are “Should I take a weight loss medication?” and “Which one is the best?”.
The answers are both straightforward and ambiguous.
Anti-obesity medications are FDA approved for patients who have a BMI over 30 and for patients who have a BMI over 27 if they also have a weight related medical condition, like high blood pressure, high cholesterol, type 2 diabetes mellitus or sleep apnea. I also use medication if a patient has obesity based on body fat percentage, which is generally accepted to be >32% for women and >25% for men.
If a patient meets these criteria, there are a several scenarios I typically use medication.
Most of my patients have tried to lose weight on their own many times before they come to see me. In the past, they have struggled with hunger and cravings, and untreated, it has usually been the primary reason they didn’t succeed in losing weight or keeping weight off. As my mentor, Dr. Debbie Horn, always says, “It’s not willpower, it’s physiology”. We know that as soon as a person starts losing weight, their body fights against weight loss by altering hormone levels to increase hunger and slow metabolism. These hormones don’t just change for a brief period of time to try to stop the weight loss, it looks like these changes persist for years afterwards.
Abnormal physiology in the brain drives inappropriate hunger and cravings and slows metabolism. In simplified terms, anti-obesity medications act at the hormone level to decrease this inappropriate hunger. If a patient is struggling with hunger or cravings, I use medication to control the symptoms. The other reason I use medication is when a patient’s weight loss trajectory isn’t what I expect it to be.
So what are the medications?
There are now six medications that are FDA approved to treat weight. I frequently use five of the six and will focus on those. The sixth (Orlistat) commonly causes undesirable gastrointestinal side effects, so I avoid it unless a patient specifically asks for it.
Phentermine is what most people commonly think of as an appetite suppressant. It was FDA approved in 1959 and works primarily to increase levels of the hormone norepinephrine. Phentermine is available generically and is the least expensive at around $25 per month.
Qsymia is a combination of phentermine and topiramate that was FDA approved in 2012. While phentermine mostly acts to increase norepinephrine levels, the exact mechanism of action of topiramate for weight loss is not fully understood. The cost of qsymia varies depending on insurance coverage and if it is prescribed in the brand name form or as the two generic medications.
Contrave is a newer generation medication that was FDA approved in 2014. It’s actually a combination of two older medications, bupropion and naltrexone. The way in which they cause weight loss is not completely understood, but we do know they act in the brain by increasing levels of the hormones dopamine and norepinephrine. Contrave, without insurance coverage, is about $100 per month with a savings card from the pharmaceutical company.
Saxenda is also a newer generation medication that was FDA approved in 2014. Saxenda is a daily injection that acts on a receptor for a hormone called Glucagon-Like-Peptide 1 in the brain. Without insurance coverage, Saxenda is about $1000 per month with a savings card from the pharmaceutical company.
Belviq is another newer generation medication that was FDA approved in 2012. It acts on serotonin receptors in the brain. Without insurance coverage, Belviq costs about $100 per month with a savings card from the pharmaceutical company.
The cost of the medications varies widely depending on insurance coverage. All of the medications reduce hunger and cravings, and they should always be used in combination with nutrition, physical activity and behavioral changes. None of the medications are recommended during pregnancy. Which medication is best really depends on the individual patient in terms of their medical history and other current medications. To find out which is best for you, talk to your obesity medicine physician.
In terms of how well they work, it’s very difficult to compare them. No head to head studies have been done to compare the medications to each other, and even the data on how well the medications work was reported differently between studies, again, making it difficult to compare them.
The effect on weight loss of each medication should be evaluated after a specific period of time. What works for one person, doesn’t necessarily work for another. Sometimes, the dosage needs to be adjusted or another medication needs to be added, although combining medications has not been well studied.
Another common question I receive is, can I stay on the medication?
The FDA approval for phentermine is for 12 weeks of use, however many obesity medicine physicians prescribe the medication for longer periods of time; this is called off-label prescribing. The other anti-obesity medications (including Qsymia, which contains phentermine) do not have a time limit associated with their FDA approval.