Posted by ben on June 29, 2005, at 14:25:34
Medscape Medical News 2005. © 2005 Medscape
Melatonin Agonist Shows Benefits in Treating Bipolar Depression
June 21, 2005 (Pittsburgh) — Patients with bipolar depression may get relief from the adjunctive use of agomelatine (Valdoxan), according to U.S. and French investigators who presented their findings here at the Sixth International Congress on Bipolar Disorder."This is the first melatoninergic antidepressant, and it may fill a need in bipolar depression," said Joseph R. Calabrese, MD, in an interview. "Others have not shown benefit, and we think that agomelatine may work because it has a different mechanism of action."
The new agent works on the melatonin 1 and melatonin 2 receptors and also has 5-HT2c antagonist properties, as do selective serotonin reuptake inhibitors (SSRIs), said Dr. Calabrese, a professor of psychiatry, at Case Western Reserve University, Cleveland, Ohio. He added that the hope is that a melatoninergic agent would be less likely to cause hypomania and rapid cycling than are SSRIs.
The expectation is that agomelatine would be used in an adjunctive manner along with a mood stabilizer, according to Dr. Calabrese, who was the coinvestigator. The lead investigator was Judith D. Guelfi, MD, a consultant psychiatrist in the Psychiatric Clinic at Hôpital Sainte-Anne in Paris, France.
The investigators were interested in agomelatine's potential to treat bipolar depression because it has been shown to be effective in treating major depressive disorder. The drug has been submitted for approval to the European Agency for the Evaluation of Medical Products, and approval is expected in early to mid-2006.
Therefore, in an initial study, Drs. Guelfi and Calabrese recruited 21 patients with bipolar I disorder who were experiencing a major depressive episode to see if adjunctive treatment with agomelatine in addition to a mood stabilizer would improve their symptoms. The investigators used the Hamilton Rating Scale for Depression-17 (HAM-D17), and eligible patients had a score of at least 18, and a response was defined as a reduction of at least 50% in the HAM-D17 score, and remission was defined as a HAM-D17 score of no more than 6.
All patients received 0.25 mg of agomelatine daily during an initial six-week acute period, in which 47% of patients responded during the first week of treatment, and in which 85% had responded by the end of the acute phase. Afterward, 19 patients continued for an extension phase from weeks 6 to 52; 11 patients completed the study. Among those who continued, 10 were in remission by the end of the study. Among the eight discontinuations, two were for lack of efficacy, three were for adverse events, and of the remaining three, one had recovered by week 18 and did not feel the need for ongoing therapy, one had withdrawn consent, and one had poor compliance. Fifteen adverse events occurred, including two manic or hypomanic episodes. Generally, though, treatment was well tolerated, with an average Young Mania Rating Scale score that was 4 at onset and declined throughout the study period to 2 by the study's end.
"We were looking for a signal that agomelatine could be effective in bipolar depression, and we think the findings warrant further study," said Dr. Calabrese. "We would anticipate that agomelatine would be used as an adjunctive therapy." However, Dr. Calabrese cautioned that larger studies would be needed that replicated these findings to make a more definitive statement.
Sixth ICBD: Abstract P163. Presented June 17, 2005.
Reviewed by Gary D. Vogin, MD
poster:ben
thread:521130
URL: http://www.dr-bob.org/babble/20050627/msgs/521130.html