Phentermine shows highest side effect reports among obesity medications in Korea

Recent data indicates that phentermine, often referred to as a weight loss pill, has been the most reported drug for side effects among obesity treatments prescribed in Korea.

Such data was confirmed through a joint study conducted by Kyung Hee University's School of Pharmacy and Ajou University's School of Medicine and Pharmacy, which analyzed 13,766 reported side effects from obesity treatments in the Ministry of Food and Drug Safety's Adverse Event Reporting System between 2010 and 2019. Professors

The study found that Phentermine exhibited the most severe side effects, followed by Novo Nordisk's and Saxenda (ingredient: liraglutide).

Phentermine, an appetite suppressant, decreases hunger sensations in the brain and increases feelings of fullness by activating neurotransmitters. It's categorized as a narcotic in Korea and is available only by prescription and not to those under 16.

Saxenda slows the digestion time to increase feelings of being full and suppress appetite. Originally developed as a diabetes treatment, its effective application for obesity widened its therapeutic scope.

The average age of patients who reported side effects was 41, with a significant majority (89.02 percent) being female, and 4,168 cases were either confirmed or likely linked to the weight loss medications.

Phentermine accounted for 33.2 percent (1,385 cases), while Saxenda followed at 27.7 percent (1,155 cases).

Common side effects include gastrointestinal disorders (29.1 percent), central and peripheral nervous system disorders (19.2 percent), and mental disorders (16.9 percent).

However, severe cases most frequently involved mental disorders (25.7 percent) and nervous system disorders (19 percent), with 30 percent of the severe mental disorders attributed to Phentermine.

Men frequently reported gastrointestinal-related side effects, while women showed a higher rate of cardiac and pulse-related disturbances. Additional analysis revealed men were more likely to take multiple obesity treatments.

Notably, 16 percent of patients were found to be using two or three anti-obesity drugs simultaneously, a factor deemed to increase the risk of side effects significantly.

The research team stated that the risks of severe side effects stemming from Phentermine and Saxenda were quite high, with patients taking the drug 1.73 times more likely for mental disorders, 4.57 times for respiratory issues, 5.70 times for cardiovascular problems, and a staggering 22.95 times more likely for liver and bile duct disorders compared to people not taking the drug.

"The prevalence of adverse drug events (ADEs) induced by anti-obesity medications has been increasing annually," the team said. "Ongoing ADE collection and future analysis on anti-obesity medications is imperative, considering limited real-world data-based pharmacovigilance investigation along with the limitations of this study."

Moreover, further studies are needed to determine the impact of a specific anti-obesity medication, including newly approved agents, on the risk of the reported ADEs in consideration of potential confounding variables, the team added.

The team stressed that close monitoring of ADE incidences pertaining to anti-obesity medications is crucial for promoting patient safety.

Journal of Global Health published the results of the study.