FDA Approves New Diet Drug Contrave
Posted on September 16, 2014
The U.S. Food and Drug Administration ("FDA") approved a new diet drug called Contrave. The drug is actually a combination of two existing drugs: Naltrexone and Bupropion.
Naltrexone is currently approved to help treat drug addicts. The drug works by keeping the user from feeling pleasure from drinking alcohol and opioids, such as heroin or certain pain medications. Buproprion is the generic of Wellbutrin, an antidepressant which is used to elevate mood. It is also used sometimes to help people stop smoking. The downside of the drug is that a lot of people feel suicidal on it, so it has a black box warning on it. Contrave is an extended release tablet.
This is the third diet drug the FDA has approved recently. The other two on the market now are Qsymia and Belviq. All three of the drugs were initially rejected by the FDA, which was concerned about side effects and effectiveness. Qsymia and Belviq aren't selling that great, and it's unclear whether Contrave will catch on either. For one thing, the drugs don't decrease appetite. They are expensive and are not covered by many health insurance policies.
But the main reason for the poor sales are that the drugs just don't work very well. In double blind, proper clinical trials patients who took Contrave lost, on average, 4.1% of their bodyweight after a year. 42% of the patients taking Contrave managed to lose 5% of their body weight, while they were exercising and dieting. 17% of the patients taking the placebo also lost 5% of their bodyweight. That's not much for a drug that costs a lot and might make you want to jump off the nearest cliff.
These results were for overweight, non-diabetic patients. The numbers for the trial of Type II diabetic patients were even worse. In that trial only 36% of the patients taking Contrave lost an average of 2% more than the patients taking the placebo. Only 36% of those taking Contrave lost at least 5% of their bodyweight. 18% of the patients taking a placebo also lost at least 5% of their bodyweight over one year of taking the drug, while exercising and eating healthily.
Drug industry execs wring their hands over poor sales of diet drugs, but is it any wonder that these new drugs are not selling well? The side effects of Contrave include seizures, suicidal thoughts, high blood pressure, increased heart rate, insomnia, nausea, constipation, vomiting, headaches and dry mouth. Pregnant women must not take the drug. The marketing materials say that the drug won't work without diet and exercise.
The last diet drug combination that worked well was the drug combination popularly known as fen-phen. That was short for fenfluramine/phentermine. Fenfluramine was pulled from the market after Wyeth was hit with a class action lawsuit in which evidence showed that the drug caused sometimes fatal pulmonary hypertension and heart valve problems. Billions were awarded in damages. Phentermine is a safe appetite suppressant that is still around, which provides mild reduction in hunger over a short time.
Japanese company Takeda Pharmaceutical Company is distributing the drug, and it's going to spend a lot of money on marketing in order to outsell Belviq and Qsymia (which should not be that difficult). You should be seeing print ads, internet ads and possibly television ads. Doctors will also be getting samples of the drugs, so you can try before you buy.
The current generation of diet pills is less than impressive.
Here's Dr. Jennifer Ashton explaining Contrave and possible side effects for ABC News.