Meds for migraine may be beneficial for weight loss, study suggests

Triptans, a class of migraine medications, are found to be very effective in reducing obesity, according to research done on obese mice.

Animals in the research who received a daily dosage of triptans ate less and lost weight over the course of a month.

“We’ve shown that there is real potential to repurpose these drugs, which are already known to be safe, for appetite suppression and weight loss,” said study leader Chen Liu, PhD, Assistant Professor of Internal Medicine and Neuroscience and an investigator in the Peter O’Donnell Jr. Brain Institute.

Over 41% of American adults are obese, which raises their risk of developing heart disease, stroke, diabetes, and several forms of cancer. The majority of obesity therapies include healthy food and exercise.

Serotonin, a chemical messenger present in many parts of the body and brain, is well-known to scientists to play a significant role in hunger. Serotonin receptors, which sense serotonin and tell cells to alter their behaviour in response, come in 15 distinct varieties. Since prior medications that targeted specific individual receptors, such as fen-phen and lorcaserin (Belviq), were pulled from the market owing to adverse effects, researchers have struggled to comprehend the function of each serotonin receptor in appetite.

Triptans, which are used to treat acute migraines and cluster headaches, work by targeting a different receptor — the serotonin 1B receptor (Htr1b) — that had not previously been well studied in the context of appetite and weight loss, said Dr Liu.

For the new study, the researchers tested six prescription triptans in obese mice that were fed a high-fat diet for seven weeks. Mice fed two of these drugs ate about the same amount, but mice fed the other four ate less. After 24 days, mice were given a daily dose of the drug frovatriptan lost, on average, 3.6% of their body weight, while mice not given a triptan gained an average of 5.1% of their body weight. Dr Liu and his colleagues saw similar results when they implanted devices into the animals that gave them a steady dose of frovatriptan for 24 days.

“We found that these drugs, and one in particular, can lower body weight and improve glucose metabolism in less than a month, which is pretty impressive,” said Dr Liu.

Since triptans are generally prescribed for short-term use during migraines, Dr Liu suspects that patients would not have noticed the longer-term impacts on appetite and weight in the past.

To determine exactly how frovatriptan impacts food intake and weight, the researchers engineered mice to lack either Htr1b or Htr2c, the serotonin receptor targeted by fen-phen and lorcaserin. In mice without Htr1b, frovatriptan no longer could decrease appetite or cause weight loss, while cutting out Htr2c had no effect. This confirmed that the drug worked by targeting the serotonin 1B receptor.

“This finding could be important for drug development,” said Dr Liu. “We not only shed light on the potential to repurpose existing triptans but also brought attention to Htr1b as a candidate to treat obesity and regulate food intake.”

The team went on to show exactly which neurons in the brain were most important for the role of Htr1b in mediating appetite, homing in on a small group of cells within the brain’s hypothalamus.