constricts the urogenital diaphragm and stimulates synchronized rhythmic
contractions of the vas deferens. Hence, agents that enhance e1-adrenergic transmission (*)
have the capacity to restore/maintain anterograde ejaculation
Urinary bladder
Stimulates urogenital sphincter constriction and contractility of the vas deferens Inhibits * Ephedrine, imipramine ** Chlorpromazine, clomipramine, perphenazine, phenoxybenzamine, risperidone, thioridazine
Legend
Notes about the scheme
Initial stimulation of the sympathetic nerves from sympathetic motor neurons emerging in
segments T12(11)–L3, produces emission of semen from the ampulla of the vas deferens into the posterior urethra. Following the initial emission of semen into the posterior urethra, sympathetic contraction of the posterior urethra and closure of the bladder neck, together with parasympathetically (originating from S2–S4) induced contraction of the bulbocavernosus and ischiocavernosus muscles and pelvic floor activity, leads to antegrade ejaculation through the urethral meatus. Failures in the initial step can lead to anejaculation, which is defined as total failure of seminal emission into the
posterior urethra. Failures in the latter two steps lead to retrograde ejaculation, which is defined as substantial propulsion of seminal fluid from the posterior urethra into the bladder.
Retrograde ejaculation can appear as complete (no antegrade fraction) or incomplete (only minimal antegrade emission). Diagnostic clues to anejaculation are complete absence of antegrade ejaculation combined with non-viscous,
fructose-negative, and sperm-negative
postorgasmic urinalysis. Diagnostic evidence of retrograde ejaculation includes absent or intermittent emission of ejaculate, orgasm without ejaculation, ability to empty the bladder during erection, and the absence of
spermatozoa and fructose in postcoital
specimens of urine. In the absence of antegrade ejaculation, retrograde ejaculation is the most common cause of ejaculatory dysfunction and accounts for 0.3–2% of cases of male infertility. The most common reasons for retrograde ejaculation in patients attending infertility clinics are a history of retroperitoneal lymph node dissection, diabetes mellitus, bladder neck surgery, transurethral resection of the prostate, and idiopathic retrograde ejaculation (no identifiable cause for ejaculatory dysfunction), which together account for more than 80% of patients with retrograde ejaculation. Spinal cord injury is the most common diagnosis in patients with anejaculation.
Various medical treatments have been proposed for the treatment of anejaculation or retrograde ejaculation. Drugs used in the medical treatment of retrograde ejaculation include a-adrenergic agonists or anticholinergic and antihistaminic drugs, which either increase the sympathetic or decrease the
parasympathetic tone of the bladder. Drugs frequently used are imipramine, midodrine,
chlorpheniramine plus phenylpropylamine,
and brompheniramine. Frequent side-effects at the doses given are various degrees of dizziness, sleep disturbances, weakness, restlessness, dry mouth, nausea, and sweating. The most effective pharmacological treatments of retrograde ejaculation include
chlorpheniramine plus phenylpropylamine, imipramine, and midodrine (with 50–80%
success rates).
Premature ejaculation is defined as
persistent or recurrent ejaculation with minimal sexual stimulation before, on, or shortly after penetration and before the person wishes it. Behavioral therapies include the stop–start technique, the squeeze technique, and other psychotherapeutic interventions. However, it has been shown that the initial positive effects of behavioral techniques disappear after 3 years.
Pharmacotherapy is also used to delay ejaculation. Initially, local anesthetic ointments were recommended, but later case reports and open trials described the beneficial effects of
monoamine oxidase inhibitors (MAOIs), clomipramine, benzodiazepines, and selective serotonin reuptake inhibitors
(SSRIs) such as fluoxetine, paroxetine, and
sertraline.
The involvement of central serotonergic neurotransmission in human ejaculation has been investigated mainly in animal studies. To date, it seems that the beneficial effect of SSRI treatment in premature ejaculation results from 5-HT2Creceptor stimulation. Among the SSRIs,
paroxetine has been demonstrated to be more
effective than clomipramine and the other
SSRIs. Moreover, it has been suggested that
long-term SSRI administration is much more efficient than short-term treatment.4–6
5.4 Drugs affecting sexual function
Antipsychotic drugs
Others
Sexual adverse side-effects associated with various psychotropics
Psychotropics
Sexual adverse side-effects
High capacity to cause the specific adverse effect Moderate capacity to cause the specific adverse effect Minor capacity to cause the specific adverse effect Negligible capacity to cause the specific adverse effect The adverse effect has not been reported with this drug
In cr ea sed libido Dec re ased libido Er ectile dysf un ctio n Pr ia psi m In hibited ej ac u la tio n * Pa in fu l ej ac u la tio n In cr ea sed libido Dec re ased libido Dec re ased o rg as m c ap acity Chlorpromazine Men Women Haloperidol Fluphenazine Perphenazine Pimozide Thioridazine Trifluoperazine Carbamazepine Isocarboxazid Lithium Phenelzine Tranylcypromine
* Might also cause inhibited orgasm capacity
References
1. Meston CM, Frohlich PF. The neurobiology of sexual function. Arch Gen Psychiatry 2000; 57: 1012–1030.
2. Halaris A. Neurochemical aspects of the sexual response cycle. CNS Spectr 2003; 8: 211–216.
3. Segraves, RT. Pharmacologic management of sexual dysfunction: benefits and limitations. CNS Spectr 2003; 8: 225–229.
4. Kamischke A, Nieschlag E. Update on medical treatment of ejaculatory disorders. Int J Androl 2002; 25: 333–344.
5. Waldinger MD, Berendsen HHG, Blok BFM et al. Premature ejaculation and serotonergic antidepressants induced delayed ejaculation: the involvement of the serotonergic system. Behavioural Brain Res 1998; 92: 111–118. 6. Waldinger MD, Olivier B. Utility of selective
serotonin reuptake inhibitors in premature ejaculation. Curr Opin Invest Drugs 2004; 5: 743–747.