Clinic Location & Map

#09-40 Mt Elizabeth Novena Specialist Centre
(located within Mt Elizabeth Novena Hospital)
38 Irrawaddy Road
Singapore 329563

Phone: +65 6235 1180
Fax: +65 668 41310
Emergency: +65 6535 8833

Clinic Hours

Monday - Friday 9:00am - 5:30pm
Saturday 9:00am -12:30pm
Sunday / Public Holiday Closed

Erectile Dysfunction

Picture of Erectile Dysfunction

Erectile dysfunction (ED) is the constant inability to attain or maintain erection sufficient for satisfactory sexual intercourse. The causes of ED are advancing age, diseases like hypertension, diabetes mellitus, neurological diseases, pelvic surgery / injury (especially prostate surgery), and medications. The basic process of erection requires blood to enter the penis as well as remain in the penis until the act of intercourse is completed. This requires a good blood supply, intact nerves, normal testosterone levels, and libido. Hence, any disease that affects the blood vessels, nerves, (esp. diabetes, hypertension, drugs) hormone levels (esp. aging) and mental health (esp. stress, depression, alcohol, drugs) can cause ED. Because of this strong association, ED can also be a harbinger of neurovascular diseases and should not be viewed as a disease in isolation. Indeed, many men have subsequently been found to have significant heart disease and early diabetes upon further evaluation. An unfortunate few may develop catastrophic heart attacks or stroke after taking medication to restore erection, and thus wrongly implicate the medication as the cause.


Picture of the IIEF-5 questionnaire

Fig 1. The IIEF-5 questionnaire

How is ED diagnosed? This is based on the history of the patient but a questionnaire is also available to help patients and doctors determine if ED is present and how severe it is. This is the IIEF-5 questionnaire and a score of 21 or less indicates the patient has a problem with his erection. [Fig 1] There are also xray studies that can be done to verify ED, eg. colour doppler ultrasound and venous cavernosography, but these are reserved for those who do not respond to treatment, and in whom surgery is contemplated.


The treatment of ED falls into 4 groups:

  1. Psychotherapy - this is for those whom the doctor has assessed to have stress or depression related ED.
  2. Drugs [Fig 2] - either injection of a drug called prostaglandin (PGE1) into the penis or oral medication like PDE5 inhibitors
  3. Devices [Fig 3]- a vacuum pump sucks out blood into the penis and thereafter, a ring placed round the base of the penis prevents the blood from draining out
  4. Surgery [Fig 4] - involves tying up leaking veins or inserting in an implant to artificially create an erection.
Picture of PGE1 injection into the penis

Fig 2. PGE1 injection into the penis

Picture of Vacuum pump device

Fig 3. Vacuum pump device

The vacuum pump (Fig 3) is rather cumbersome to use because it requires the placement of a rubber ring (c) at the base of the penis and using a hand-held pump (b) to create a vacuum within the cylinder (a) so as to draw blood into the penis.

Venous leak ligation surgery does not have sustained results while penile implant surgery is expensive and carries risks of infection and implant failure.

Picture of Penile prosthesis

Fig 4. Penile prosthesis

PGE1 injections are painful to give and short-lived. Subsequently, a compound that prevented nitric oxide levels (responsible for erection) from being destroyed was discovered. This compound is PDE5 inhibitor (PDE5i). The first such drug was Viagra® which was launched in 1998. Subsequently, two other drugs, Cialis® and Levitra® came into the market. These drugs are effective in up to 90% of men with ED. Viagra® and Levitra® lasts up to 4 hours. Cialis® has a longer duration of action (36 hours), while Levitra® has the fastest onset (30 mins). Despite the initial fears and reports of deaths, these drugs are safe, as long as they are not given to men who have severe heart disease and who are on nitrate drugs. The main side effects are headache, flushing and nasal congestion. The recent reports of sudden blindness are rare occurrences and seen mostly in those with long-standing hypertension and diabetes mellitus. What about natural remedies? Every country has its own herbs and plants that claim to be effective. From ginseng to tongkat ali, these plants have even been made into pills. There are no conclusive studies done to show that they are superior to PDE5i drugs. The placebo rate in well-conducted scientific trials have been shown to be as high as 30%.

What about premature ejaculation - is this a form of ED too? Currently, this condition is considered a form of anxiety state, although many patients who suffer form ED also seem to have premature ejaculation. Some believe this to be a precursor to ED. There are drugs available, from anaesthetic gel eg. lignocaine which is applied to the penis head some 30 to 60 mins beforehand, to tablets like clomipramine, taken 4 hours beforehand.

One should not rely on drugs to restore one’s sexual health. A more sensible way is prevention and control of diseases like hypertension, diabetes, hyperlipidaemia and correcting bad lifestyle, eg. smoking, drinking, work-stress. The temptation is to buy drugs from private sellers or through the internet because of cheaper price or convenient delivery. These drugs contain reduced doses of PDE5i and may even contain harmful chemicals. They not only put these men at further risk of drug interactions with concurrent medicines. In the event of a serious event, it would be impossible to seek redress or compensation because these illegal vendors would not be easy to trace or prove they were directly responsible. ED sufferers should always seek proper medical evaluation before starting drug treatment.