Even if premature ejaculation (PE) is the most common sexual disorder in men, it is often poorly understood.
PE affects almost 30% of men worldwide, considering only the diagnosed cases.
The difficulties in understanding PE are in fact the difficulty of expression what PE is and the symptoms of PE.
The general perception of what truly is a “normal ejaculation time”, as well as diversity of social, and economic characteristics among men with the complaint of PE, have raised concerns in the medical communities.
Recent definitions of PE include the definition of International Society of Sexual Medicine(ISSM) from 2014, the definition published by the American Psychiatric Association (APA in the Diagnostic and Statistical Manual of Mental Disorders 5th Edition , and the definition embraced by International Statistical Classification of Diseases and Related Health problems 10th Revision (ICD-10) in 2016.
Ejaculation that always or nearly always occurs prior to or within about 1 minute of vaginal penetration from the first sexual experience (lifelong PE) or a clinically significant and bothersome reduction in latency time, often to about 3 minutes or less (acquired PE).
The inability to delay ejaculation on all or nearly all vaginal penetrations.
Negative personal consequences, such as distress, bother, frustration, and/or the avoidance of sexual intimacy.
Diagnostic and Statistical Manual of Mental Disorders 5th Edition
A persistent or recurrent pattern of ejaculation occurring during partnered sexual activity within approximately 1 minute following vaginal penetration and before the individual wishes it.
The symptom must have been present for at least 6 months and must be experienced on almost all or all (approximately 75–100%) occasions of sexual activity (in identified situational contexts or, if generalized, in all contexts).
The symptoms cause clinically significant distress in the individual” and “The sexual dysfunction is not better explained by a nonsexual mental disorder or as a consequence of severe relationship distress or other significant stressors and is not attributable to the effects of a substance/medication or another medical condition.
International Statistical Classification of Diseases and Related Health problems 10th Revision
The inability to control ejaculation sufficiently for both partners to enjoy sexual interaction.
The theory of the psychologically overanxious constitution of PE dated back from 1943, when Bernhard Schapiro, a German endocrinologist, argued that PE is a psychosomatic disturbance caused by a combination of psychological factors leading to ‘‘an inferior ejaculatory apparatus as a point of least resistance for emotional pressure’’. Dr Schapiro described two types of premature ejaculation.
Type A (the hypotonic type) leading also to erectile dysfunction who were believed to respond well to nerve tonics, testosterone, prolonged sexual rest, sports, hydrotherapy, and electrotherapy.
Type B (the sexually hypertonic or hyper-erotic type), representing a continuously present tendency to ejaculate rapidly from the ﬁrst act of intercourse. These patients were treated with sedatives.
After the very fortunate development of sildenaﬁl for the treatment of an erectile disorder, pharmaceutical companies have become interested in sexual medicine. In addition to their widespread prevalence, sexual dysfunctions have been found to impact significantly on interpersonal functioning and overall quality of life in both men and women.
Sexual medicine is aiming nowadays to improve the treatment and to boost the benefits of medication administered to patients with sexual disorders.
Between 2000 and 2012, a few companies have investigated existing compounds for the treatment of PE. Only the pharmaceutical company Johnson & Johnson was able to obtain a registration by the European Medicines Agency (EMEA) for their drug dapoxetine, an SSRI with a short half-life, for the on-demand treatment of PE.
Dapoxetine, also known as Priligy (commercial name) was studied through the works of the Dapoxetine Study Group.
Dapoxetine belongs to a class of drugs called selective serotonin reuptake inhibitors (SSRIs) which are frequently prescribed to treat patients suffering from depression. Prior to dapoxetine becoming available, psychotherapy (e.g. cognitive behaviour therapy) was widely used to treat PE.
More recently, several SSRIs (other than dapoxetine) have been used off-label to treat PE, but currently, dapoxetine is the only oral drug approved to treat PE.
These SSRIs were not developed to treat PE, in contrast with dapoxetine which was specifically developed for this purpose and has a different pharmacological profile to the other SSRIs, with properties making it suitable for on-demand dosing. Briefly, the pharmacology of dapoxetine may be summarized as follows:
Dapoxetine is rapidly absorbed following oral administration, whereas other SSRIs take several days or even weeks to reach steady-state concentrations
Peak plasma levels of dapoxetine are reached in approximately 1 hour following a dose of 30 mg or 60 mg
Dapoxetine is rapidly eliminated; its initial half-life is approximately 1.4 hours for both doses, compared with 21 hours to 4 days for other SSRIs
Dapoxetine has a terminal half-life of 18.7 hours for the 30 mg dose and 21.9 hours for the 60 mg dose
Even with multiple dosing, the pharmacokinetics of dapoxetine is unchanged, and it does not appear to accumulate significantly. These pharmacokinetic characteristics make dapoxetine ideal for on-demand dosing, which reduces the probability of unwanted side effects.
Previous Phase II studies identified the optimal dose to be 30 mg initially, with an increase to 60 mg (the maximum recommended dose) if required. Pharmacodynamic studies identified the optimal dose administration time to be 1–3 hours before sexual intercourse.
In a dapoxetine extension study (with 1774 participants) 7, the volunteers received on-demand dapoxetine 60 mg, regardless of prior treatment group in the original studies (dapoxetine 30 mg, 60 mg, or placebo). At 9 months, approximately 70% of patients reported “fair”, “good”, or “very good” control over ejaculation. These data represent clear evidence of a significant improvement over placebo in perceived control over ejaculation in adult patients with PE taking dapoxetine 30 mg or 60 mg on-demand.
The strongest evidence for the use of dapoxetine in adult males with premature ejaculation is for the main disease-oriented outcome of intravaginal ejaculatory latency time or IELT, reported in several publications. Dapoxetine significantly and consistently increased IELT by approximately 3–4 minutes, representing a 3–4-fold increase in IELT.
Dapoxetine is contraindicated in men with moderate to severe hepatic impairment and in those receiving concomitant therapy with potent cytochrome P450 3A4 inhibitors (eg, ketoconazole, ritonavir, telithromycin), thioridazine, monoamine oxidase inhibitors, serotonin reuptake inhibitors (eg, SSRIs, serotonin-norepinephrine reuptake inhibitors, tricyclic antidepressants) or other medicinal/herbal products with serotonergic effects (eg, hypericum [St John’s wort]).
Dapoxetine is not recommended in men with severe renal impairment, and caution is advised in men with mild to moderate renal impairment. Alcohol and recreational drugs should be avoided when taking dapoxetine.
PE remains a complex condition, which is incompletely characterised despite advances in our understanding over the last decade. As a consequence, the ability to define and classify the condition has been difficult. A move to a more evidence-based approach as applied by the ISSM has improved the clinicians’ ability to define those who need treatment, as well as perform further research in this complex condition.
Dapoxetine is the only drug specifically formulated and licensed for PE in adult males. The unique pharmacology of dapoxetine makes it ideal for on-demand dosing, allowing great convenience and flexibility for the patient.
Dapoxetine is clearly a promising treatment option for PE, and its use can result in greater quality of life for the patient and their sexual partner.
American Psychiatric Association. Diagnostic and statistical manual of mental disorders: DSM-5™. 5th ed. Arlington, VA: American Psychiatric Publishing, 2013.
International Statistical Classification of Diseases and Related Health problems 10thRevision.Available online: http://apps.who.int/classifications/icd10/browse/2016/en [PubMed]
Marcel D Waldinger- History of premature ejaculation
Pryor JL, Althof SE, Steidle C, Rosen RC, Hellstrom WJ, Shabsigh R, Miloslavsky M (2006) Dapoxetine study group. Efﬁcacy and tolerability of dapoxetine in treatment of premature ejaculation: an integrated analysis of two double-blind, randomised controlled trials. Lancet 368:929–937
Porst H, McMahon CG, Althof SE, et al. Baseline characteristics and treatment outcomes for men with acquired or lifelong premature ejaculation with mild or no erectile dysfunction: integrated analyses of two phase 3 dapoxetine trials. J Sex Med. 2010;7(6):2231–2242
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