Source: DGNews  |  Posted 6 years ago

By Steve Pridgeon

VANCOUVER, CANADA -- November 11, 2005 -- Depressed patients taking mirtazapine together with fluoxetine (Sarafem) or venlafaxine responded to treatment better than those taking fluoxetine (Sarafem) alone.

However, relapse rates upon discontinuation of medication were greater in patients with the best remission rates, according to research presented here at the 55[^]th[] annual conference of the Canadian Psychiatric Association (CPA).

Remission rates in major depression are low (25% - 45%) when monotherapy is used. Despite this, combination therapy is rarely employed until the patient proves to be resistant to treatment.

"Patients typically start out with just one medication," said Philippe Tremblay MD, Institute of Mental Health Research, University of Ottawa, Canada. "Then, if it doesn't work, there is a delay before they start combination therapy."

"We wanted to see the result of putting patients on a combination to begin with," he added.

During his poster presentation on November 4[^]th[], Dr. Tremblay presented the results of a prospective, randomized, double-blind study which evaluated the effects of combination therapy on remission rates in patients with major depression.

Dr. Tremblay and colleagues ransomized 105 patients to one of four treatment arms for 42 days: fluoxetine plus placebo; fluoxetine plus mirtazapine; venlafaxine plus mirtazapine; or buproprion plus mirtazapine.

Patients who met the study entry criteria at any visit during the study were deemed to have relapsed. Remission was defined as a Hamilton Rating Scale for Depression (HAMD-17) score of 7 or less.

Patients who achieved a score of 12 or less on the Montgomery Asberg Rating Scale continued in a 6-month extension phase, in which they were switched to monotherapy. Patients on fluoxetine plus placebo or fluoxetine plus mirtazapine continued on fluoxetine alone. Patients in the venlafaxine plus mirtazapine or buproprion plus mirtazapine regimens continued on mirtazapine alone.

At day 42, patients in the three combination arms had significantly lower scores on the HAMD17 than did patients on fluoxetine alone (P = .002).

Remission rates were significantly higher in the fluoxetine plus mirtazapine and the venlafaxine plus mirtazapine arms than among patients on monotherapy. The rates of 52% and 58%, respectively, were more than double those of fluoxetine alone, at 25%.

The percentage of patients who responded to treatment was significantly higher in the combination therapy arms than in the monotherapy arms, but the difference was not significant.

The researchers concluded that use of drug combinations at treatment initiation is well tolerated and improves remission rates within a standard treatment period.

[Presentation title: Combining Antidepressants to Improve Treatment Outcome in Depression. Abstract P-14]