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is that the second time is the charm for drug Qnexa diet? The Food and Drug Administration (FDA) review the data on the weight loss drug, again - an advisory group will meet on Wednesday - after rejecting the drug for approval once already in 2010.
Endocrinologic and Metabolic Drugs Advisory Committee voted the agency initially 10-6 against Qnexa's approval over concerns that it may increase heart rate and cause birth defects - concerns the FDA still has the second time. According to the FDA's disclosure documents, the Advisory Committee will be asked Wednesday to consider whether the manufacturer of Qnexa, Vivus, should conduct a clinical trial on cardiovascular risk before approval - a move that could delay significantly its reach in the market. Vivus proposes to post-approval study.
The key question for the panel is whether Qnexa is effective for weight loss - clinical trials suggest that it is, although in the second year of a trial, participants regained some of the weight they lost within the first year - but if its potential side effects outweigh its benefits.
Qnexa is a combination of two existing drugs - phentermine, an appetite stimulant suppression, and topiramate, an antiepileptic drug that is usually prescribed to control epilepsy, but also affects the appetite.
To address these concerns, the manufacturer of Qnexa, Vivus, suggested the drug is approved only for use in men and in women of childbearing potential not. This type of labeling work around did not meet the FDA, however, and the agency has asked the company to find a way to prevent pregnant women from using it.
Qnexa is not the first, it will not be the last weight loss pill to get approval from the FDA. The market is ripe for a new drug to help Americans lose weight, "We're really going to Weight Watchers to bariatric surgery regarding treatment options," said Joseph Nadglowski, president of the Obesity Action Coalition , an advocacy group for patients in Tampa, Fla., in an interview with Bloomberg. "For many, this is a pretty big difference."
But the FDA has an uneven history with diet drugs and an ever growing bar for new weight loss remedies. After a brief history of the success of the diet drug industry, failures and near misses.
Amphetamines
The original diet of drugs date back to the 1950s Amphetamines simply worked by stimulating the metabolism around, cause the body to burn more calories faster. The problem - as with any energy system pushed to its limits - was that the cells are not made to burn, burn, burn. They eventually burn, leading to heart problems, chest pain, palpitations, insomnia and other health problems.
Amphetamines, which stimulate energy and mood are as addictive as they tap into the brain's reward system. After their potential for abuse occurred, US and European officials have banned most amphetamine based drugs, but the drug is still available, often hidden in the diet remedies in South America.
Fen-phen and Redux
A new drug combination fenfluramine appetite suppressant and existing phentermine, fen-phen was all the rage in the mid-1990s, leading to a loss of weight in hundreds of thousands of Americans. In 1996, after media attention, the FDA approved a related drug, dexfenfluramine as Redux, which was the same as fen-phen, but with fewer side effects. However, the side effects were always serious: in the summer of 1997, the FDA revealed that 82 patients had developed defects in their heart valves while on fen-phen, and seven patients came down with the same condition on Redux. Other patients developed pulmonary hypertension, a potentially fatal lung disease, and JAMA study confirmed previous reports that both fen-phen and Redux caused brain damage in laboratory animals . After millions of prescriptions written in 1997 both fenfluramine and Redux were withdrawn from the market.
sibutramine (Meridia)
Since amphetamines made too much risk of addiction and other side effects, researchers have begun to focus on ways to trick the brain into want less food. Sibutramine, approved in 1997, worked on brain chemicals that affect appetite by blocking the reuptake of neurotransmitters such as norepinephrine and serotonin, the drug may suppress the desire to eat and convince the body that it was full, helping dieters to lose 5% to 10% of their body weight in a few months. After studies showed users were more likely to develop heart problems and stroke, however, the drug was withdrawn from the market in 2010.
Lorcaserin (Lorqess)
Because sibutramine, lorcaserin focused on changing brain chemicals, especially serotonin, convincing the body it was full. But an FDA panel recommended in 2010 against the approval of the drug because studies in which female rats taking the drug developed an alarming number of mammary tumors. The committee also asked the manufacturer to Lorqess, Arena, to perform additional tests on the drug's effect on users with diabetes and heart disease, conditions that commonly affect those who are overweight.
Contrave
A combination of two drugs already approved the antidepressant drug bupropion and naltrexone anti-addiction pill, Contrave has got the nod of an advisory committee to the FDA, which voted 13-to 7 for approval in 2010, but was ultimately rejected by the body itself over concerns that the drug increased the risk of heart attacks, strokes and other cardiovascular problems. The FDA said the minimal weight loss experienced by users (4.2%) does not justify the potential cardiovascular risks.
In another sign of FDA high threshold is set for diet drugs, the agency said Orexigen Therapeutics, the manufacturer of Contrave, would need to conduct further studies and long-term possible cardiac risks associated with Contrave, before approval would be considered. Such a trial would cost the company hundreds of millions of dollars -. enough to kill further development if Orexigen decides the diet market expected pill does not justify the cost
Orlistat (Alli, Xenical)
Currently, the only drug approved scheme on the US market, orlistat is available in two (Xenical) formulations over-the-counter (Alli) and prescription. Orlistat works not in the brain but in the intestine, promoting weight loss by preventing the body from absorbing the fat in food. The drug, which is intended to be used in combination with a low-fat diet and exercise program can help users lose 50% more weight than they would with diet and 'exercise. In this case, excess gas, oily or fatty stools and even oily stains
Alice Park is a writer at TIME. Find her on Twitter at @aliceparkny. You can also continue the discussion on TIME's Facebook page and on Twitter at @TIME.
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