Oral Medication

Erectile Dysfunction

The Efficacy of Oral Medication

Our center provides oral medications for the treatment of insufficient rigidity / ED that work as a selective enzyme inhibitor. They can inhibit cGMP-specific phosphodiesterase type 5 (PDE-5), an enzyme that maintains the amount of cGMP in human body (when a man is sexually aroused, cGMP will be released to the penis). Balancing the level of cGMP will allow the smooth muscle of a penis to relax, which increases the blood flow coming to the penis.

Mechanism of erection and oral medication

During arousal the following occurs:

  • The man’s central nervous system stimulates the release of a number of chemicals, including nitric oxide (NO), the main contributor for eliciting and maintaining erection.
  • Nitric oxide stimulates production of cGMP, a chemical that relaxes the smooth muscles in the penis. Smooth muscle relaxation allows blood to flow into the tiny pool-like cavernous sinusoids, resulting in increased rigidity of the penis.
  • This increased blood flow nearly doubles the diameter of the cavernous sinusoids.
  • Penile veins surrounding the chambers are squeezed almost completely by this pressure.
  • The veins are unable to drain blood out of the penis and so the penis becomes rigid and erect.

After ejaculation or arousal, cGMP is broken down by an enzyme called phosphodiesterase-5 (PDE5), and other compounds are released that cause the penis to become flaccid (unerect) again. PDE5 inhibitor helps maintain erection by inhibiting the action of PDE5. Since there is no activation of the NO / cGMP system in the absence of sexual stimulation, taking those oral medication does not independently cause an erection.

Patients that are Not Recommended

Some patients are not recommended to take oral medication for the treatment of insufficient rigidity / ED. If a man has the following situations, he should not take in any oral medication that contains PDE-5 without the instruction of a doctor:

  • taking nitrate drugs to treat angina pectoris or alpha-blocker (except taking 0.4mg Flomax) for high blood pressure or having prostatic hypertrophy
  • suffering from severe heart disease, such as unstable angina pectoris, history of heart attack, or irregular heartbeat. Sildenafil contained in oral medication will increase the load of the heart, particularly in the presence of psychological and physiological stresses. Therefore, men with heart disease should receive check and evaluation to determine whether having sex will increase the risk of heart attack
  • recent history of stroke
  • suffering from low blood pressure
  • suffering from uncontrollable diabetes
  • suffering from uncontrollable high blood pressure
  • receiving anticoagulant treatment
  • suffering from severe heart failure
  • suffering from retinitis pigmentosa (people with this this genetic disease will not produce phosphate esters, therefore they will not respond to sildenafil)

Premature Ejaculation

Our Center provides oral medication that belongs to a member of selective serotonin reuptake inhibitor (SSRI) family, for the treatment of uncontrollable / premature ejaculation in men between 18 to 64 years old[1]. Oral medication delays ejaculation by inhibiting the serotonin transporter and increasing serotonin’s action at the post synaptic cleft. 

Without doctor’s consultation, patients who have below conditions should not take any medication that consists of SSRI to treat PE：

  • men with permanent pacemaker or with cardiac problem, including heart failure, heart block or any valvular disease
  • men with history of fainting or severe renal impairment
  • men with moderate to severe hepatic impairment and receiving CYP3A4 inhibitors such as ketoconazole, ritonavir, and telithromycine
  • men with current or past mental problems such as depression and receiving thioridazine, monoamine oxidase inhibitors, SSRIs, serotonin-norepinephrine reuptake inhibitors, or tricyclic antidepressant