ED is defined as the inability to get and maintain an erection that is sufficient for
satisfactory sexual intercourse. In simple terms it means soft penis during sex.
How does erection occur?
The process of erection begins with stimulation either by sight, smell or taste which
then causes the release of chemicals called nitric oxide (NO) from the walls of blood
vessels and nerve endings. This chemical then activates another chemical called
guanylate cyclase, which in turn increases another chemical known as cyclic
guanosine monophosphate (cGMP). This chemical (cGMP) causes relaxation of the
smooth muscles in the penis. This causes the blood vessels bringing blood to the penis
to dilate (vasodilatation) which in turn will lead to increased blood flow into the
penis. What happens next is engorgement of the penis which gives it the erection and
rigidity.
The erection and rigidity is maintained because the engorgement of the penis
compresses the blood vessels draining blood out from the penis. Therefore drainage of
blood is impeded and the engorgement of the penis with blood stays.
To reverse this, another chemical called the 5-phosphodiesterase, is produced. This
chemical causes the breakdown of cGMP, which will then lead to softening or
flacidity of the penis.
Causes of ED
Since the process of erection requires stimulation, intact nerves and blood vessels, any
diseases or conditions that affect any of these may lead to ED. Psychological
conditions such as depression and stress are not uncommonly associated with ED.
Certain medications/drugs like those used to treat hypertension and psychiatric
disorders may cause ED. Recreational drugs like marijuana are also notorious for it.
Other than that, diseases that affect the blood vessels like cholesterol clogging the
vessels (atherosclerosis) as well as those affecting the nerves like diabetes (neuropathy) will lead to ED. Surgeries around the pelvis like the removal of the
prostate (prostatectomy) and trauma are also other common causes of ED. Hormones
like testosterone also play a role in erection and when there are low levels of
testosterone(hypogonadism), erection will be affected.
Diagnosis
Most of the time, no special test is required to make a diagnosis. Doctors commonly
use a questionnaire known as the International Index of Erectile Function (IIEF) to
grade the severity of the ED. The other grading is the Erection Hardness Score (EHS).
A physical examination as well as some simple blood tests for sugar (glucose),
cholesterol and testosterone will usually be done. In certain cases, further tests like nocturnal penile tumescence test (NPT),
cavernosogram, areteriogram or colour Dopper ultrasound may be needed. These tests
are usually done for more complicated cases and in those not responding to treatment.
In the NPT test, it measures tumescence and rigidity at both the base and the tip of the
penis (via bands placed around the tip and base of the penis) and recordings are made
throughout the night before computer-based analysis of the results. Cavernosogram is
mainly used to look for venous leak i.e. blood escaping too quickly from the penis to
maintain erection. Penile arteriogram on the other hand is to assess the flow of blood
into the penis. Colour Doppler ultrasound assesses the flow of blood in and out of the
penis.
Treatment
There are a few treatment options for ED.
1) Healthy lifestyle
Maintaining a healthy lifestyle by itself has been proven to be effective and may
be the only treatment needed. It is still important to maintain a healthy lifestyle
even when other treatments are given as well. Healthy lifestyle means no
smoking, reduction of weight, well balanced diet as well as exercise.
2) Phosphodiesterase-5 inhibitors (PDE5 inhibitor)
These are pills/medications taken orally. Examples are sildenafil (Viagra),
tadalafil (Cialis), vardenafil (Levitra). These medications blocks the action of the
chemical known as phosphodiesterase-5 (which breaks down cGMP). Therefore,
it increases the concentration of cGMP in the penis and thus increases blood flow
and engorgement in the penis. Side effects of PDE5 inhibitors include redness of the face (flushing), headache and backache. It should be used with caution in
those with heart diseases. Those on medications known as nitrates for heart
problems should avoid PDE5 inhibitors. It needs to be noted that stimulation is
still needed before the medication works.
3) Intracavernosal prostaglandin injection.
These are medications (prostaglandin) which are injected directly into the penis. It
causes an increase in the concentration of chemicals known as cyclic adenosine
monophosphate (cAMP). cAMP similarly to cGMP, causes increased blood flow to the penis causing erection. This action is direct and no stimulation is needed.
Possible complications include bleeding and plaques formation in the penis.
4) Vacuum erection device
This is an appliance which is used to cup the penis. Suction is then applied to
create a vacuum around the penis. This will draw out blood to the penis causing it
to get engorged and achieve erection. A band is then applied at the base of the
penis to keep the blood trapped in the penis therefore maintaining the erection.
The drawback of this device is that the penis feels cold and there may be
numbness and bruises around the penis.
5) Penile implants.
These are devices which are inserted via surgery into the penis. There are the
inflatable and semi-rigid ones. The semi-rigid (malleable) types are basically rods
which are inserted into the penis to give the erection and rigidity. The inflatable
penile implant consists of two cylinders inserted into the penis. There is a pump
which sends water into the cylinders, causing them to get inflated and this results
in an erect penis. This pump is inserted into the scrotum. When erection is not
needed, a valve is pressed which sends the water back to a reservoir causing the
cylinders to be deflated. The success rate is above 95% though cost is a major
factor as the device costs above RM20,000.
6) Psychological treatment
Finally, there is also cognitive behavioural therapy (CBT) and sex therapy which may
be able to help those who have no problem with the nerves or blood supply to the
penis but are affected by their emotional and mental well being. It can also be used
together with the other medical therapies.
