Primary or lifelong PE originates at the beginning of the patient’s sexual life and continues to appear from then on. Secondary PE means that the disorder appeared after a period of time of sexual normality. It is likely that this type of PE is caused by diabetes mellitus, atherosclerosis, prostatitis, UTI and neurological diseases. There are other aspects that may be involved, such as behavioral therapy or depression but up to now no psychological study has revealed any connection.
Following the success of selective serotonin re-uptake inhibitors (SSRI), fluoxetine and paroxetine, a new neurobiological method of treatment of PE is being promoted. -1 noradregenic stimulation mediates ejaculation and possibly with cholinergic influences. SSRI have no sympathicolytic effects on the parasympathetic system meaning that the effects of these drugs are in the CNS. A theory by Adler-Graschinsky proposes that serotonin inhibits the noradrenergic mechanism of orgasm especially on the presynaptic neurons. These neurons promote sympathetic neurotransmission and cause the delay of ejaculation.
Studies on animals have proved that serotonin receptors 5-HT2C and 5-HT1A have a great deal of influence on ejaculation. The 5-HT2C receptor reduces the ejaculatory latency (IELT) while 5-HT1A delays ejaculation.
A way of ascertaining that treatment of PE is effective is the increase of the value of the IELT. Nonetheless, there is not a universally-accepted value of IELT for patients with or without PE. The value ranges from 1 min (Waldinger) to even 7 minutes (Schover). The American Psychiatric Association (APA) diagnoses PE not according to a specific time of ejaculation but according to the sexual satisfaction of the couple. A common method for rating sexual satisfaction is from the report of the patient and his partner. A standard method is the International Index of Erectile Function questionnaire (IIEF) which provides information on overall sexual satisfaction, but is not recommended for PE diagnosis because it does not measure IELT.
A characteristic of patients with PE is penile sensitivity, so by treating this there is a possibility of treating PE. Treating penile sensitivity can delay the ejaculation by numbing the effects. A study was conducted in which 42 patients were divided in 2 groups, group A was given lidocaine-prilocaine solution and group B a placebo cream. The patients were selected at random and they were asked to assess the effects of the treatment and what happened during the sexual act by measuring IELT. The results revealed that there is an increase in the value of IELT in group A but not group B. Further results suggest that men with PE have a higher degree of cortical representation of sensory stimuli from the glans penis than men without PE.
These studies have reported that the local anesthetic off-label combination of lidocaine-prilocaine is among the most effective there is and should be placed directly to the penis. There is controversy regarding how much time one should leave the cream on before intercourse. Studies by Choi have showed that if applied one hour before and then removed just before intercourse there is an increase of 2 minutes of IELT in 80% of the cases as opposed to 15% of those who have applied placebo creams. Sexual satisfaction also increases in 82% of the cases as opposed to 20% of those who used placebo.
In the study involving the two groups A and B, the cream was left on for 10-20 minutes and the IELT increased in 75% of the subjects as opposed to 15% of those with placebo. Morales suggested the cream be applied for 30 minutes but tried to produce a cream called ‘eutectic mixture’ in aerosol formulation and succeeded in reducing the time with 10-15 minutes. Atikeler also examined the optimum time for cream appliance and concluded that 20 minutes would prove most effective. Berkovitch was the one who realized that as a consequence of cream appliance the penile area will be partially numbed and thus ejaculation will be delayed. The disadvantage is still the loss of sensitivity in the penile area. Moreover, cases have been reported of female partners suffering from numbness in the vaginal or clitoral area, particularly when the men do not use a condom, which could prevent this unwanted effect.
Another way to prevent the numbness is washing the penis. Unwanted side-effects were reported in the 2 group study, 17% of group A suffering from retarded ejaculation, penile irritation (without use of condom) and vaginal sensitivity in the partner.
The reported results have proved that the lidocaine-prilocaine cream can be an effective treatment of PE. Further studies will enable doctors to confirm these findings on a long-term period.
