Introduction
Dapoxetine is a selective serotonin reuptake inhibitor, for the treatment of premature ejaculation. In a phase II proof-of-concept study conducted by PPD, dapoxetine demonstrated a statistically significant increase in ejaculatory latency when compared to placebo.
Uses
Dapoxetine is a selective serotonin reuptake inhibitor used in the treatment of premature ejaculation.
For the treatment of premature ejaculation.
Associated Conditions
Pharmacodynamics
Dapoxetine is a selective serotonin reuptake inhibitor currently undergoing trials through Alza (under license from GenuPro, a collaboration between Eli Lilly and PPD). Dapoxetine is a short-acting SSRI drug currently being considered for approval by the Food and Drug Administration (FDA) for the treatment of premature ejaculation in men, which would make it the first drug approved for such treatment. Despite two clinical trials finished in 2006, experts doubt it will be approved by the FDA soon because SSRIs come with undesirable side-effects after long-term use, such as psychiatric problems, dermatological reactions, increase in body weight, lower sex-drive, nausea, headache, upset stomach and weakness, thus not significantly outweighing the benefit of premature ejaculation medication versus the risks. By contrast with SSRIs approved for depression, which take 2 weeks or longer to reach steady-state concentration, dapoxetine has a unique pharmacokinetic profile, with a short time to maximum serum concentration (about 1 h) and rapid elimination (initial half-life of 1-2 h).
Mechanism of Action
The drug's mechanism of action is thought to be related to inhibition of neuronal reuptake of serotonin and subsequent potentiation of serotonin activity. The central ejaculatory neural circuit comprises spinal and cerebral areas that form a highly interconnected network. The sympathetic, parasympathetic, and somatic spinal centers, under the influence of sensory genital and cerebral stimuli integrated and processed at the spinal cord level, act in synergy to command physiologic events occurring during ejaculation. Experimental evidence indicates that serotonin (5-HT), throughout brain descending pathways, exerts an inhibitory role on ejaculation. To date, three 5-HT receptor subtypes (5-HT(1A), 5-HT(1B), and 5-HT(2C)) have been postulated to mediate 5-HT's modulating activity on ejaculation.
Absorption
Rapidly absorbed.
Half Life
Initial half-life of 1-2 hours.
Dosage
Adult men (18 to 64 years of age): The recommended starting dose for all patients is 30 mg, taken as needed approximately 1 to 3 hours prior to sexual activity. The maximum recommended dosing frequency is once every 24 hours. If the effect of 30 mg is insufficient and the side effects are acceptable, the dose may be increased to the maximum recommended dose of 60 mg. Dapoxetine may be taken with or without food.
Children and adolescents: Dapoxetine should not be used in individuals below 18 years of age. Elderly (age 65 years and over): Safety and efficacy of Dapoxetine have not been established in patients age 65 years and over as limited data are available in this population.
Patients with renal impairment: Caution is advised in patients with mild or moderate renal impairment. Dapoxetine is not recommended for use in patients with severe renal impairment.
Patients with hepatic impairment: Dapoxetine is contraindicated in patients with moderate and severe hepatic impairment
