The History of Drug Treatment for Obesity: Do The Pros Outweigh The Cons

This article is going to look at the history of drug treatment for obesity. Treatment of obesity usually starts with lifestyle (diet and exercise) and psychological changes, followed by drug plans and bariatric surgery. The role of obesity drugs are to decrease consumption (appetite suppressant), absorb nutrients, or to increase energy expenditure. As there isn’t many drugs currently licensed, history would suggest that the side effects are too dangerous and that the cons outweigh the pros.

A combination of phentermine and diethylpropion was used in the 1930s, these were sympathomimetics. Although still available in private clinics, adverse effects include restlessness, insomnia, increased blood pressure and heart rate, and an increased chance of developing pulmonary hypertension. Phentermine has also been combined with topiramate, which was approved in the USA in 2012.

Fenfluramine and dexfenfluramine are 5HT releasing drugs, however are also associated with pulmonary hypertension. Fenfluramine was combined with phentermine until evidence suggested the grouping was associated with cardiac valve disease.

Evidence suggests that cannabinoids stimulate hunger via the CB1 receptor, therefore an antagonist could be effective. Rimonabant is a CB1 antagonist and has shown to be effective in both animal and human studies. The drug was withdrawn due to significant psychiatric adverse effects, the drug is still available on the web however. Some cannabinoid antagonists could be effective, some studies suggest rimonabant combined with an opioid antagonist or 5-HT2c antagonist may be useful.

Currently the only available anti-obesity drug is orlistat, which works by blocking pancreatic and gastric lipase (no lipid digestion, no lipid absorption). Orlistat has been shown to help people lose weight and improve risk factors associated with obesity, such as high blood pressure. However, orlistat does have some side effects, this includes malabsorption of vitamins ADEK, bloating, steatorrhea, and linked with liver toxicity. Liragluitide is a GLP-1 analogue and a new option, it has shown to provide weight loss to diabetic patients.

Although it is tempting to use drugs to provide help with weight loss, the side effects must be taken into consideration. Unless the person is dangerously obese, then nothing beats lifestyle changes.