New York, NY: US regulatory authorities have announced that they will decide this spring on whether to approve the prescription use of the cannabinoid receptor antagonist SR 141716A, to be marketed by Sanofi-Aventis Pharmaceuticals as a diabetes treatment and anti-obesity drug under the trade name Acomplia (Rimonabant). In July, the selective cannabinoid blocking agent received regulatory approval in a handful of European nations as a dietary aid. Acomplia is the first cannabinoid antagonist ever to be approved for human consumption.
The US Food and Drug Administration (FDA) will review newly published clinical data indicating that Acomplia significantly lowers blood sugar levels in humans compared to placebo. The FDA had previously denied Sanofi permission to market Acomplia in the United States.
In clinical trials, patients who take Acomplia on a daily basis lose, on average, 14 pounds their first year, and an additional 2.4 pounds their second year. However, published reports indicate that more than 15 percent of subjects who try the drug discontinue its use because of intolerable side effects, including nausea, anxiety, headaches, upper respiratory tract infections, and depression. At least one study reports a 2.7-fold increased risk of psychiatric disorders in Acomplia users.
Acomplia works by blocking the natural binding of endogenous cannabinoids (as well as exogenous cannabinoids such as THC) to the neuronal CB1 receptors, causing users to lose their appetites. (Volunteers administered both Acomplia and cannabis in clinical trials also report decreased feelings of euphoria and other physiological effects associated with THC.) However, because the endocannabinoid receptor system is believed to be involved in the regulation of a broad range of primary biological functions — including appetite, body temperature, mood regulation, blood pressure, bone density, reproduction, learning capacity, and motor coordination — some experts are concerned that the long-term use of Acomplia may eventually contribute to a host of significant adverse health effects.
“CB1 receptors commonly play protective roles in minimizing the consequences of free-radical induced, age-related illnesses, … as well as the aging process itself,” says University of Colorado at Colorado Springs biology professor Dr. Robert Melamede. “The long-term use of CB1 antagonist drugs such as Acomplia may turn out to be disastrous [because] they may promote the illnesses that CB1 activity normally protects against.”
In preclinical trials, newborn mice injected with Rimonabant refuse feeding and often die days after birth. Mice genetically bred to lack the CB1 receptor also suffer from numerous health defects such as cognitive decline, hypoalgesia, decreased locomotor activity, and increased mortality compared to healthy controls.
At least one published case study also reports that daily use of the drug may have triggered neurological symptoms of multiple sclerosis in a volunteer with no known history of the disease.
According to Sanofi spokespersons, the FDA will make its determination by April 26. Sanofi-Aventis is the third largest pharmaceutical company in the world.
For more information, please contact Paul Armentano, NORML Senior Policy Analyst, at (202) 483-5500.