A Pharmacist Talks About a New Weight Loss Product: Contrave

Contrave is a new weight loss product that is in the investigational stage. Contrave is a combination weight loss product containing sustained-release forms of bupropion and naltrexone.

Bupropion is already on the market under the trade names of Wellbutrin and Zyban, for depression and smoking cessation, respectively.

Naltrexone is already available in a non-sustained-release oral form opiate blocker and an injectable sustained-release form opiate blocker. Naltrexone is used to treat alcohol and narcotic addiction.

Known Side Effect History of Contrave Ingredients

One of buproprion's side effects is weight loss. In clinical studies, using bupropion alone, when dosed at 300mg per day, 14 percent of patients lost more than 5 pounds. At 600mg daily, 19 percent experienced a 5-pound weight loss. Also note that six percent of patients that were given placebo also had a weight loss of five pounds or more. Other side effects of bupropion have included dry mouth, anxiety, nausea, nervous system stimulation, insomnia, pounding or racing of the heart, seizures, psychosis, mania, and elevated blood pressure.

Side effects of oral naltrexone have included nausea, vomiting, decreased appetite, headache, dizziness, fatigue and anxiety. In addition to the known side effects with the regular-release oral form of naltrexone, other side effects may occur with the injectable sustained-release form. The additional known serious side effects may include: blurred vision or eye problems, wheezing, difficulty breathing, thoughts of causing self harm, fever, dark urine, nausea, stomach pain, jaundice of the skin or eyes, ear pain and ringing in the ears, and others. Side effects are more likely to occur in patients who are addicted to opioids. Among addiction-free patients, naltrexone administration has not been associated with a predictable profile of serious adverse or untoward events.

Contrave Side Effects

Available information regarding side effects with Contrave is from clinical trials. Seven serious adverse reactions during trials were thought "possibly related to Contrave treatment." They included two patients with gall bladder inflammation, two had seizures, one had palpitations, one had tingling, and one experienced dizziness. Nausea was the most frequent cause of study-participant dropout. Other frequent side effects were constipation and headache.

Contrave Study Results

The manufacturer of Contrave reported in January that those who completed one year of treatment on Contrave lost 11.5% of their body weight, compared to 7.3% on placebo. It is very important to note that all of the patients in Contrave trials were on a complete weight loss program that included counseling, dieting, and exercising. The manufacturer called it "an intensive behavior modification regime."We don't have evidence of what Contrave would do for an overweight person if taken by itself without using it as part of a comprehensive weight loss program including diet and exercise.

The manufacturer claims, "Contrave patients experienced reductions in the frequency and strength of food cravings and an increased ability to control their eating compared to placebo." Phase III of the clinical trials showed, "... significant improvements in cardiovascular and metabolic risk factors such as waist circumference, visceral fat, HDL cholesterol and triglycerides.

Summary:

I have been a practicing pharmacist for over 30 years. I have never seen positive, long-lasting weight loss by people who have used weight loss medications. They often tend to take weight loss medications as a substitute for learning to alter their behavior.

Contrave is an investigational new weight loss product that is currently undergoing studies. Contrave contains ingredients that cause weight loss, curb food cravings, and increases metabolism. However, the ingredients in Contrave can also cause serious or uncomfortable side effects. Both of the ingredients in this weight loss product commonly cause nausea.

Even though all participants in the study had "significant weight loss" and sustained the weight loss for over one year, all of the participants in the Contrave weight loss program were on a diet and exercise program. The results of the clinical studies for this new weight loss product prove the value of altering lifestyle as a good weight loss method.

I agree with Dr. David Katz, a weight loss expert at Yale University. He had these comments about the Contrave information, "I have limited enthusiasm for pharmacotherapy to manage weight, and these results certainly don't change my view on the topic."

SOURCES:

Nancy Hellmich. 3 New Prescription Diet Drugs May Soon Help Obese. Usatoday.com

Daniel J. DeNoon. Contrave: New Weight Loss Drug Advances. Webmd.com

No author given. Orexigen Therapeutics Presents Phase 3 Trial Results of Contrave for Treating Obesity. News-medical.net

No author given. Contrave Review. Dietspotlight.com

Lauren Cox. New Diet Drug Attacks Craving Center. Abcnews.go.com

No author given. Press Release. Orexigen.com