A new diet drug, tesofensine, produced weight loss that was twice that of Acomplia (rimonabant) in phase II clinical trials, according to Professor Arne Astrup of the University of Copenhagen reporting online and in an upcoming edition of the medical journal, The Lancet.

In a randomized, placebo-controlled phase II study of 203 obese patients conducted in five Danish obesity management centres, mean weight loss for those on placebo was under 5 pounds while those on a .5 mg dose of tesofensine lost almost 25 pounds.

“We conclude that tesofensine 0.5 mg, once daily for 6 months, has the potential to produce twice the weight loss as currently approved drugs; however, larger phase III studies are needed to substantiate our findings," the researchers said.

Danish pharmaceutical company Neurosearch, which accidentally discovered that tesofensine promoted weight loss during studies of the drug for treatment of Alzheimer's Disease and Parkinson's Disease, has said it is preparing for Phase III trials of the diet drug.

Tesofensine is a triple monoamine re-uptake inhibitor which blocks the re-uptake of the neurotransmitters serotonin and nor-adrenaline in the brain with no direct effect on the monoamine receptors.

The drug is believed to induce weight reduction both by reducing appetite and by increasing the metabolic rate that helps the body burn fat.

The most frequently reported adverse events from the drug are mild to moderate, and include dry mouth, sleep disturbances, nausea, constipation and diarrhea.