Potential benefits of Labopharm's novel trazodone formulation published

Nov 11 2009

Labopharm Inc. (TSX: DDS; NASDAQ: DDSS) today announced an article has been published in the international journal of neuropsychiatric medicine, CNS Spectrums October, 2009 issue (www.cnsspectrums.com), citing the potential benefit of its novel trazodone formulation, which contains Contramid(R). Labopharm's Contramid is the clinically validated proprietary technology that controls the release of active substances from oral medications to optimize drug delivery.

The article is authored by Dr. Stephen Stahl, adjunct professor of psychiatry, University of California, San Diego School of Medicine as part of a series entitled Trends in Psychopharmacology, the Mechanism of Action of Trazodone: A Multifunctional Drug.

"Although trazodone has traditionally been used as a low dose hypnotic, a new controlled release formulation that has the potential to improve the tolerability of high doses may provide an opportunity to revisit this multifunctional drug as an antidepressant as well," writes Dr. Stahl in the article's abstract.

The article states that high doses of trazodone must be delivered to take advantage of the multifunctional activity of the drug. Contramid technology contained within the controlled-release trazodone tablet is designed to maintain plasma concentrations of the drug at levels high enough to inhibit serotonin re-uptake, providing antidepressant effects, while simultaneously blocking 5HT2A and 5-HT2C receptors. Blocking these receptors is thought to avoid side effects such as sexual dysfunction, weight gain and development or exacerbation of anxiety often seen with other antidepressant drugs. Controlled-release trazodone containing Contramid was designed to avoid peak blood levels of trazodone associated with multiple administrations of immediate-release formulations. Such peak levels are thought to affect tolerability and possibly result in the intolerable sedation seen in some patients.

"Controlled-release trazodone should theoretically allow adequate dose escalation to administer high doses for antidepressant action while avoiding sedation of the immediate release formulation," concludes Dr. Stahl. "As an antidepressant, the new trazodone formulation should be as effective as selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs), yet as a serotonin antagonist reuptake inhibitor (SARI), have a low incidence of anxiety, insomnia and sexual dysfunction."

The efficacy and safety profile of Labopharm's controlled release trazodone formulation has been demonstrated in a placebo-controlled phase III study, the results of which were discussed in a separate article entitled Extended Release Trazodone in Major Depressive Disorder: A Randomized, Double-Blind, Placebo-Controlled Study, which was published in the May 2009 issue of the peer-reviewed journal Psychiatry (Edgemont) (Volume 6, Number 5) (www.psychiatrymmc.com).