May 5, 2004 - Results from an analysis presented today show that long-term treatment with Lamictal(R) (lamotrigine) is not associated with clinically relevant changes in weight when used in patients with bipolar I disorder compared to placebo. The results were presented at the 157th annual meeting of the American Psychiatric Association (APA) in New York, NY.
The data reports on the long-term impact of mood stabilizers on body weight. Weight gain is an area of concern for psychiatrists and patients in the long-term treatment of bipolar I disorder. It has previously been reported that side effects such as medication-related weight gain may have a negative impact on compliance. In fact, medication compliance is considered to be an essential component of the long-term management of bipolar disorder.
Researchers evaluated weight data retrospectively from patients with bipolar I disorder in two 18 month maintenance studies of Lamictal, lithium and placebo. The analysis showed that for patients taking Lamictal and placebo, a low proportion of patients experienced clinically important weight changes and weight-related adverse events. Furthermore, no statistically significant weight differences were seen between patients taking Lamictal and placebo over the course of the study. For patients taking lithium, the study found that body weight increased over time and that after one year of treatment, patients experienced moderate weight gain, although not statistically significantly different from placebo.
"This study shows that weight gain is not an inherent part of treatment for people with bipolar I disorder," said Gary Sachs, M.D., Associate Professor of Psychiatry, Harvard Medical School and Director, Bipolar Disorder Clinic and Research Program, Massachusetts General Hospital. "This is good news for patients concerned about weight gain who are being treated for bipolar I disorder."
Lamictal received approval from the U.S. Food and Drug Administration in June 2003 for maintenance treatment of bipolar I disorder to delay the time to occurrence of mood episodes (depression, mania, hypomania, mixed episodes) in patients treated for acute mood episodes with standard therapy. The effectiveness of Lamictal in the acute treatment of mood episodes has not been established.
BACKGROUND ON BIPOLAR DISORDER
Bipolar I disorder is characterized by the occurrence of one or more manic or mixed episodes and often individuals also have had one or more major depressive episodes; in bipolar II disorder, a person experiences one or more major depressive episodes and hypomania (a milder form of mania with less severe symptoms). If manic and depressive symptoms overlap for a period of time, it is called a "mixed" episode. Overall, the predominant structure of bipolar disorder is depressive rather than manic.
Bipolar disorder is a lifelong condition; effective and tolerable maintenance therapy is critical to disease management. Bipolar illness is often misdiagnosed, most commonly with major depressive disorder. Inappropriate treatment due to misdiagnosis can have a harmful effect on patients potentially accelerating the natural course of the illness. When left untreated, bipolar disorder can worsen and patients can experience a greater frequency of events.
