, commonly known as appetite suppressants. The effect of the drug on chronic weight management may be to reduce appetite and food consumption by mediating the release of catecholamine from hypothalamus, but its exact mechanism is not clear. The exact mechanism of topiramate in chronic weight management is not clear. Its pharmacological effects include inducing the activity of neurotransmitter γ -aminobutyric acid to increase, regulating voltage-gated ion channels, inhibiting glutamate receptors excited by AMPA)/ potassium magnesium sulfate or inhibiting carbonic anhydrase. These effects may be related to both suppressing appetite and increasing satiety. 1) The market prospect of diet pills is broad. In the 20th century, obesity has become one of the most important public health challenges. Obesity is closely related to metabolic syndrome (cardiovascular risk factors, including hypertension, fat metabolism disorder and insulin resistance), which can shorten life expectancy. It is estimated that two thirds of Americans are overweight or obese. In addition, with the increasing adoption of western diets and lifestyles in developing countries, the number of obese patients will further increase. According to the estimate of the World Health Organization, the number of overweight and obese people in the world has exceeded 654.38+0.4 billion. 2) Less competitive products: Many kinds of diet pills have withdrawn from the market, so it is difficult for doctors to have more treatment options. Experts say that continuing to lose at least 5% weight can reduce the risk of obesity and obesity-related cardiovascular diseases and diabetes. According to the guidance issued by the regulatory authorities, 5% weight loss is only the minimum standard for weight loss, while clinicians and patients have higher expectations, and they hope that the weight loss effect will be more obvious, that is, at least 10%. Among the drugs with moderate efficacy available in the market, the market development of obesity drugs is basically inhibited because of their poor tolerance, low safety and lack of new therapies. In recent years, the delisting of diet pills has made the market and the research and development of new drugs worse. The main problem of diet pills is long-term safety. In the past 40 years, five kinds of diet pills have been withdrawn from the market because of potential safety hazards. Two of the most famous drugs, Pontimin (Fenfluramine) and Redux (Dexfenfluramine) from Wyeth Company (acquired by Pfizer) were withdrawn from the market on 1997. These two drugs were found to increase the risk of heart valve disease and were withdrawn from the market only one year later. Recently, Abbott's Meridia/Reduced Tirril (sibutramine) was delisted on 20 10 because it may cause cardiovascular disease; The mediator of Schwiya Company was removed from the list in 2009 because it may lead to heart valve disease. Acomplia (Limonaban) of Sanofi was removed from the list in 2008 because it may lead to depression or suicidal thoughts. Fentamine, the most widely used derivative of amphetamine, has been used for decades because of its low price rather than obvious curative effect or safety and reliability. Other commonly used prescription drugs for weight loss include lipase inhibitor orlistat (Xenical and over-the-counter Alli). Because orlistat often causes gastrointestinal discomfort (such as fecal incontinence or oily stool), its further use is limited. However, with the delisting of sibutramine in Europe, orlistat has become the only drug that can be used to lose weight in this region.

In the China market, on June 5438+ 10, 2009, SFDA requested that fenfluramine hydrochloride tablets and its raw materials be banned nationwide due to serious adverse reactions such as heart damage. 2010101October 30th, SFDA issued a notice and decided to stop the production, sale and use of sibutramine preparations and APIs in China. Drugs that have been put on the market will be recalled and destroyed by the manufacturer. This notice ended the sales history of sibutramine series diet pills represented by Qumei in China 10. 3) Market expectation of phentermine topiramate hydrochloride products: shouldering the heavy responsibility of expanding the market of slimming drugs. Among the newly approved slimming drugs by FDA, Qsymi (Fentamine Topiramate Hydrochloride Preparation) is closest to the expectations of doctors and patients, and can reduce the weight by 65,438+00%. However, topiramate in the composition has the risk of birth defects (cleft lip and palate), and increasing the dose can cause narcolepsy and sensory abnormalities. The risk assessment and disaster reduction countermeasures (REMS) for Qsymia include monthly pregnancy check-ups for patients of childbearing age, which are distributed in specialized mail-order pharmacies. On the contrary, Belviq is safer and more tolerant, but the average weight loss can only reach 3%~4%. According to the application schedule of the United States Drug Enforcement Administration, Qsymia may be listed before the end of 20 12, and it is currently in production, and Belviq will be listed in early 20 13. 5. Domestic listing and intellectual property rights: No products of sustained-release capsules of Phatamine Hydrochloride and Phatamine Topiramate Hydrochloride are listed in China. Topiramate raw materials have been imported in China. At present, only one enterprise in Hengrui Pharmaceutical Gang (20 13.2) in China has applied for the clinical application of new drugs (uniform drugs) of phenetamine hydrochloride and phenetamine topiramate hydrochloride sustained-release capsules.