Lower Side Effects of Milnacipran than Paroxetine in the Treatment of Major Depression Disorder among Han Chinese in Taiwan

Milnacipran is a dual-action antidepressant which inhibits both serotonin and norepinephrine reuptake. To our knowledge, it has limited affinity for most monoamine neurotransmitter receptors. With limited pharmacokinetic interaction with the cytochrome 450 system, milnacipran may have a low risk in drug interaction. The present study compares milnacipran with paroxetine, a selective serotonin reuptake inhibitor (SSRI) and which has been used clinically for years to evaluate the efficacy, patient tolerance, and side effects in the treatment of major depression. The study took place in two medical centers located in Northern and Southern Taiwan. Six-three participant who met the Diagnostic and Statistical Manual of Mental Disorder 4th edition (DSM-IV) criteria for it major depressive disorder and a total Hamilton Depression Rating Scale (HAM-D) score > 16 on the 17 item scale, were recruited. Participants first received either 100 mg/day or milnacipran (33 participants) or 20 mg/day of paroxetine (30 participants), and were then assessed with HAM-D and clinical global impression scale (CGI) for severity of the illness and global improvement, at the beginning and the end of the first, second, fourth, and eighth weeks of the drug treatment. Thirty-eight patients with major depressive disorder completed the study. No statistically significant differences were observed between the two groups in the reduction of HAM-D and CGI scores. However, side effects such as headache and tremor in the first week, psychomotor retardation and difficulty in concentration in the fourth week, and psychomotor retardation in the eighth week of treatment were significantly lower in the milnacipran group, as compared to that of the paroxetine group. We concluded that milnacipran and paroxetine had similar clinical effectiveness during the eight-week treatment of major depressive disorder. Further investigation is needed to examine the clinical suitability of this drug for patients with liver impairments and for elderly patients suffering from major depression.