Sustinex (Dapoxetine):
SSRIs can be used in the treatment of PE. However these drugs are not approved drug for this indication. SSRIs must be used with caution as there is a risk of suicidal ideation associated with the use of this class of drugs. Appropriate information and counseling of the patient must be done and patients must be followed up closely and documentation should be made that they are aware that SSRI use is “off-label” and of the small but relevant suicide risk. Therefore there is unmet treatment need for an on-demand efficacious medication for the treatment of PE. This has led to the development of Dapoxetine for this specific use.
Dapoxetine:
Dapoxetine((+)-(S)-N,N-dimethyl-(a)-[2(1naphthalenyloxy)ethyl]-benzenemethanamine hydrochloride) is the first compound specifically developed for the treatment of PE. Dapoxetine, structurally similar to fluoxetine is a potent SSRI. Reported equilibrium radioligand binding studies using human cells demonstrate that dapoxetine binds to 5-HT, norepinephrine (NE) and dopamine (DA) reuptake transporters and inhibits uptake in the following order of potency: NE < 5-HT >>DA.
Dapoxetine: Current Regulatory Status
Oral dapoxetine has been approved in various European countries, including Finland, Germany and Sweden, under the decentralized procedure and in several other countries worldwide for the treatment of men aged 18-64 years with premature ejaculation.
Efficacy and tolerability of dapoxetine in treatment of premature ejaculation:
Pryor JL et al (2006) report results from a prespecified integrated analysis of two identically designed clinical trials to determine the efficacy and tolerability of on-demand dapoxetine at two doses in patients with premature ejaculation.Two 12-week randomised, double-blind, placebo-controlled, phase III trials of identical design done independently, in parallel, at 121 sites in the USA. Men with moderate-to-severe premature ejaculation in stable, heterosexual relationships took placebo (n=870), 30 mg dapoxetine (874), or 60 mg dapoxetine (870) on-demand (as needed, 1 - 3 h before anticipated sexual activity). The primary endpoint was intravaginal ejaculatory latency time (IELT) measured by stopwatch. Safety and tolerability were assessed. All analyses were done on an intention-to-treat basis.
Improvement in IELT:
At baseline, 1623 men (62%) had IELT of 1 minute or less, with mean IELT values much the same across groups. At week 12, both dapoxetine doses were better than placebo (p<0.0001, each dose vs. placebo), and 60 mg Dapoxetine was better than 30 mg dapoxetine (p=0.0007; figure 6) Overall, IELT increased in all three groups, but the increase was greatest in those on dapoxetine (table 2). At the study endpoint, 109 (14%) of 787 patients on placebo, 232 (29%) of 801 on 30 mg dapoxetine, and 261 (34%) of 763 on 60 mg dapoxetine had an IELT of 3 minutes or more (table 2). The p values for the tests of difference of proportions between placebo and the 30 mg group, as well as between placebo and the 60 mg group, were both p<0.0001.