- Bupropion/naltrexone
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Bupropion/naltrexone Combination of Bupropion norepinephrine/dopamine reuptake inhibitor Naltrexone opioid receptor antagonist Clinical data Pregnancy cat. ? Legal status ? Identifiers ATC code ? (what is this?) (verify)
Bupropion/naltrexone (proposed trade name Contrave) is an experimental treatment for obesity in phase III clinical trials.[1] Currently being developed by Orexigen[2] in a sustained-release formulation, it is a combination of two approved drugs, bupropion and naltrexone. Both drugs have individually shown some evidence of effectiveness in weight loss, and the combination is expected to have a synergistic effect.[3] In clinical trials, patients taking Contrave combined with diet and exercise lost more weight than patients taking a placebo and following the same diet and exercise program.[4] On 31 March 2010, Orexigen submitted a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) for this drug combination.[5] On 7 December 2010, an FDA Advisory Committee voted 13-7 for the approval of Contrave, and voted 11-8 for the conduct of a post-marketing cardiovascular outcomes study.[6] Contrave's PDUFA date is 31 January 2011. Subsequently, on 2 February 2011, the FDA rejected the drug and it was decided that an extremely large-scale study of the long-term cardiovascular effects of Contrave would be needed, before approval could be considered.[7] The recommended daily dose of Contrave is two (8 mg naltrexone/90 mg bupropion) tablets taken twice daily (4 tablets total - 32 mg naltrexone, 360 mg bupropion). Upon initiation, the drug will be started with a quarter-dose (or one tablet) for one week and a pill will be added to the regimen each week until the full recommended dose is reached on Week 4.
During phase 2 testing, different dosages were used in a once daily formula. These include:
- 16 mg naltrexone - 400 mg bupropion
- 32 mg naltrexone - 400 mg bupropion
- 48 mg naltrexone - 400 mg bupropion
The second dosage (32 mg-400 mg) on average showed the best benefit-to-risk ratio.
Treatment is designed to influence the hypothalamus in order to decrease food intake over an extended period of time. Studies of almost 700 patients, 90% female, ran up to 56 weeks. The control group, overall, lost 5% of their initial body weight, or 11-16 lbs. The experimental (medicated) group lost 20-23 lbs during the same amount of time. The average starting weight for participants was 223 lbs.[8] Current medical weight loss medications average 5-22 lbs lost in 6 months.[9][unreliable source?]
References
- ^ Plodkowski, Raymond A.; Nguyen, Quang; Sundaram, Umasankari; Nguyen, Loida; Chau, Diane L.; St. Jeor, Sachiko (2009). "Bupropion and naltrexone: a review of their use individually and in combination for the treatment of obesity". Expert Opinion on Pharmacotherapy 10 (6): 1069–1081. doi:10.1517/14656560902775750. PMID 19364254.
- ^ Obesity expert named Life Scientist of the Year
- ^ Sinnayah P, Wallingford N, Evans A, Crowley MA (2007). "Bupropion and naltrexone interact synergistically to decrease food intake in mice". Obesity 15 (9): A179.
- ^ Positive 24-week Results For Contrave Phase III Obesity Treatment Study Reported By Orexigen, Medical News Today, 28 Sep 2006
- ^ Orexigen(R) Therapeutics Submits Contrave(R) New Drug Application to FDA for the Treatment of Obesity
- ^ www.orexigen.com
- ^ [1]
- ^ WebMD.com
- ^ WeightLossNYC.com, About Weight Loss Medications
Categories:- Anorectics
- Combination drugs
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