General Information

Cymbalta (duloxetine hydrochloride) is a oral dual reuptake inhibitor that enhances the levels of the neurotransmitters, serotonin and norepinephrine, which are involved in depression.

Cymbalta is indicated for the treatment of major depressive disorder (MDD), with a prominent and relatively persistent depressed or dysphoric mood, nearly every day for at least 2 weeks, that usually interferes with daily functioning. Symptoms include at least 5 of the following 9: depressed mood, loss of interest in usual activities, significant change in weight and/or appetite, insomnia or hypersomnia, psychomotor agitation or retardation, increased fatigue, feelings of guilt or worthlessness, slowed thinking or impaired concentration, or a suicide attempt or suicidal ideation.

Cymbalta is also indicated for the management of diabetic peripheral neuropathic pain.

Clinical Results

FDA approval of Cymbalta was based on four randomized, double-blind, placebo-controlled, fixed-dose pivotal studies in subjects, 18 to 83 years old, with major depression. In two studies, 123 subjects were randomized to Cymbalta 60 mg once daily while 128 were randomized to receive placebo, for nine weeks. In the third study, patients were randomized to Cymbalta 20 or 40 mg twice daily and N=91, respectively) or placebo (N=89) for 8 weeks. In the fourth study, patients were randomized to Cymbalta 40 or 60 mg twice daily (N=95 and N=93, respectively) or placebo (N=93) for 8 weeks.

Results from all four studies showed that Cymbalta demonstrated superiority over placebo as measured by improvement in the 17-item Hamilton Depression Rating Scale (HAMD-17) total score.

Mechanism of Action

Cymbalta (duloxetine hydrochloride) is a oral dual reuptake inhibitor that enhances the levels of the neurotransmitters, serotonin and norepinephrine, which are involved in depression. Duloxetine is also believed to affect stress urinary incontinence (SUI) by blocking the reuptake of serotonin and norepinephrine in the spinal cord. This inhibition stimulates increased activity of the pudendal nerve, which may increase contractions of the urethral sphincter at the opening of the bladder.

Literature References

Bymaster FP, Beedle EE, Findlay J, Gallagher PT, Krushinski JH, Mitchell S, Robertson DW, Thompson DC, Wallace L, Wong DT. Duloxetine (Cymbalta), a dual inhibitor of serotonin and norepinephrine reuptake. Bioorg Med Chem Lett. 2003 Dec 15; 13(24): 4477-80.

Goldstein DJ, Lu Y, Detke MJ, Wiltse C, Mallinckrodt C, Demitrack MA. Duloxetine in the treatment of depression: a double-blind placebo-controlled comparison with paroxetine. J Clin Psychopharmacol. 2004 Aug; 24(4): 389-99.

Wohlreich MM, Watkin JG. The Role of Duloxetine in the Treatment of Depression and Associated Painful Physical Symptoms. Prim Care Companion J Clin Psychiatry. 2003 Dec; 5(6): 286-287.