LOS ANGELES – Newer medications are much more powerful, but they come with cautions – insurer coverage can be a hurdle, and there are significant gaps in knowledge about their risks for patients with heart disease, Ken Fujioka, MD, told colleagues at the annual scientific and clinical congress of the American Association of Clinical Endocrinologists.
Dr. Fujioka, of Scripps Clinic in San Diego, shared some tips with his peers about using medications to reduce weight.
Diabetes drugs help, but may need a boost
Metformin can reduce weight by as much as 3%, Dr. Fujioka said. And there may be another benefit related to long-term weight loss maintenance, he said, citing a 15-year study of overweight or obese patients at high risk for diabetes who either received metformin, underwent an intensive lifestyle intervention, or took a placebo. Of the participants with weight loss of at least 5% after the first year, those originally assigned to receive metformin had the greatest weight loss during years 6-15. Older age, the amount of weight initially lost, and continued used of metformin were predictors of long-term weight loss maintenance, according to the researchers (Ann Intern Med. 2019 Apr 23. doi: 10.7326/M18-1605).
There are other options among diabetes drugs. Sodium-glucose cotransporter 2 (SGLT2) inhibitors – a class of drugs that includes canagliflozin (Invokana), dapagliflozin (Farxiga), and empagliflozin (Jardiance) – have a striking effect on weight loss, Dr. Fujioka said. They can cause 300 calories to be flushed out in the urine each day. But that typically doesn’t translate into weight loss of more than 20 pounds, he said, because the body doesn’t fully adjust to fewer calories.
“The patients begin to eat more,” he said. “They have to take in more calories to make up for [the loss]. They’re not consciously trying to do this. It’s a metabolic adaptation, so 2%-3% [weight loss] is about all you’ll get. You won’t get 10% or 20%.”
To drive up weight loss, Dr. Fujioka recommended adding the glucagonlike peptide–1 [GLP1] receptor diabetes drug exenatide (Byetta; Bydureon) or the appetite suppressant phentermine (Adipex-p; Lomaira) to an SGLT2 inhibitor. Recent studies have shown that the drug combinations have a greater impact on weight loss than when taken separately (Lancet Diabetes Endocrinol. 2016 Dec;4[12]:1004-16; Diabetes Care. 2017 May;40[5]:632-9).
In regard to phentermine, which acts similarly to amphetamine, Dr. Fujioka advised colleagues to be aware that “15 mg or less is really safe, but you drive pulse and heart rate beyond that.”
Consider insurance coverage and other factors
Often, insurers will pay for GLP1-receptor and SGLT2-inhibitor medications in patients with diabetes, even if their hemoglobin A1c is in the healthy range, Dr. Fujioka said, but they’ll balk at paying for specific weight-loss medications, although that can vary by the region of the country. He added that cash discount cards are available for several weight-loss drugs.