Researchers have discovered that a drug from a new class of weight-loss treatments seems to disrupt certain wiring needed for brain development in young mice. This raises concerns about using such medications, especially in children.
Scientists at the Massachusetts Institute of Technology studied the effects of a chemical that suppresses appetite by blocking cannabinoid receptors in the brain, the same brain mechanisms that make people hungry when they smoke marijuana. These new weight loss drugs are based on this idea.
"I think that the cautionary note is that these mechanisms play an important role in brain development," said Mark Bear, principal author, whose study appears in the journal Neuron.
Sanofi-Aventis' weight-loss pill known as Zimulti, sold under the brand name Acomplia in Europe, is the first in this new class of drugs. A U.S. expert panel rejected it last June because of fears it might trigger suicidal thoughts. However, other pharmaceutical companies (including Merck & Co.) are working on similar drugs right now, and this research could be quite concerning.
The researchers were specifically testing learning in the visual cortex of the mouse, a part of the brain that processes information gathered from what they see, when they discovered that some of the developmental wiring had gone astray in those animals which had consumed this compound. Their work suggested that as a result, the visual cortex was not adapting as it should.
Bear said the finding is similar to the situation with many drugs, "You have to weigh the benefits against the risks. If the benefit is related more to vanity than morbidity, I don't think the risks are tolerable," he said.