The Collison Newsletter April 2013



Erectile dysfunction, or impotence, is the inability to get and/or keep an erection that allows sexual activity with penetration. Erectile dysfunction is not a disease. It is a symptom of some other problem - physical, psychological or a mixture of both.

It is common, especially in older men. It is estimated that in Australia around a million men suffer from this symptom to some degree. Over the age of 60 years, about 60% of men have some degree of erectile dysfunction. With each decade of age, the chance of having erectile problems increases.

Erectile dysfunction should not be confused with low libido (little interest in sex) or the inability to reach an orgasm or ejaculate. Premature (too early) and retrograde ejaculation (into the bladder) are different problems that need a different approach to diagnosis and treatment.

Occasional erectile dysfunction is normal. This is often caused by alcohol, anxiety and tiredness.

The study of erectile dysfunction within medicine is called andrology, a sub-field within urology.

How Does an Erection Happen?

A penile erection is the hydraulic effect of blood entering, and being retained in, sponge-like tissue within the penis.

At a superficial level, getting an erection is a simple process. There are two tubes of spongy tissue (called the corpora cavernosa) that run along the length of the penis, and this spongy material is surrounded by a tough, fibrous, partially elastic covering.

A message is sent through the nerves that leave the lower spinal cord, telling the blood vessels entering the spongy tissue of the penis to let more blood in. The flow of blood out of the penis is then blocked off (via valves) so that the penis fills with blood and stretches within the outer casing. This creates an erection. The penis stays hard until after either ejaculation, or the removal of the sexual stimulus.

Underlying this relatively simple explanation is a very complex range of chemicals in the body that also work together to enable an erection. At any one time, the muscle cells in the spongy tissue and the blood vessels are influenced by a balance of chemical factors, some of which cause an erection and some which encourage a flaccid (soft) penis.

Causes of Erectile Dysfunction

Penile erection is managed by two mechanisms: the reflex erection, which is achieved by directly touching the penile shaft, and the psychogenic erection, which is achieved by erotic or emotional stimuli. The former uses the peripheral nerves and the lower parts of the spinal cord, whereas the latter uses the limbic system of the brain. In both conditions, an intact neural system is required for a successful and complete erection.

Many factors can interfere with achieving an erection, and often two or three factors are present at one time. Sometimes there can appear to be no obvious cause of the erectile dysfunction.

It used to be thought that erectile dysfunction was mainly caused by psychological factors. However, physical illness is a common cause. Psychological causes of erectile dysfunction can happen with physical causes. There may be multiple physical factors involved.

  • Psychological Problems

Performance anxiety


Sexual attitudes and upbringing

Relationship problems

Mental disorders such as clinical depression and schizophrenia

Psychological problems linked, for example, to employment or financial worries

Generalised anxiety disorder.

  • Neurogenic Disorders

Spinal cord and brain injuries

Multiple sclerosis

Parkinson's disease

Alzheimer's disease

Diabetic neuropathy

Pelvic surgery (prostate, bowel)

Radiation therapy (prostateand bladder cancer).

  • Metabolic Problems Affecting Blood Vessel Function


High blood pressure


High blood cholesterol

Kidney failure

Sleep apnoea.

  • Reduced BloodFlow

Atherosclerosis (narrowing of the arteries)

Surgical damage to blood vessels.

  • Medications, Alcohol and Other Drugs

Alcohol excess

Recreational drugs

Nicotine (tobacco smoking)

Prescribed medications used in the treatment of : high blood pressure, depression, psychiatric disorders, high cholesterol, cancer (chemotherapy)

  • Urological Problems

Peyronie's disease (cavernosal disorder)

Pelvic trauma.

  • Iatrogenic Causes (Medically Caused)

Surgical intervention for a number of conditions may remove anatomical structures necessary to enable an erection, damage nerves, or impair blood supply. Complete removal of the prostate gland and radiation therapy to that area are common causes of erectile dysfuntion; both are treatments for prostate cancer.

  • Erectile Dysfunction and Age

There is no doubt that the ageing penis has less responsive muscle cells, which interferes with good erections. Like the rest of the ageing body, 'muscle tone' in the penis reduces with age, as do many other aspects of sexual function. Arousal can take longer. It may take much longer before a second erection happens, and usually the erection is not as firm or hard.




The diagnosis is made by the patient. "I can't get it up ... It won't stay hard etc, etc". When erectile dysfunction (impotence) is experienced, it is important to seek medical advice, since the inability to gain an adequate erection may be a symptom of an underlying medical condition(s) as yet undiagnosed (as listed above).

Diagnosis of erectile dysfunction does not need complicated tests. A general health history, as well as sexual history, will be taken by your doctor, a physical examination of the penis, testes and prostate will be carried out, and blood tests for glucose (diabetes), cholesterol and testosterone levels will be done.

A useful and simple way to distinguish between physiological and psychological erectile dysfunction is to determine whether the patient ever has an erection. If never, the problem is likely to be physiological. If sometimes (however rarely), it could be physiological or psychological.

Nocturnal Penile Tumescence (NPT) is the spontaneous occurrence of a penile erection during sleep or when waking up. All men without physiological erectile dysfunction experience this phenomenon, usually three to five times (sometimes more) during the night. It typically happens during REM sleep. The cause of NPT is not known with certainty, but is probably linked to activity of the noradrenergic neurones of the locus ceruleus in the brain stem. A full bladder may stimulate an erection. The presence of NPT rules out a physiological cause of erectile dysfunction and the erectile problems are then presumed to be due to a psychosomatic illness such as sexual anxiety or other psychological conditions listed above.


The treatment depends on the cause. Treating the cause may restore normal erectile function.

Erectile dysfunction is typically the first clinical manifestation of cardiovascular disease, making it a helpful early marker of men who are likely to die of heart attacks. There is a strong relationship between erectile dysfunction and high blood pressure, high cholesterol, angina, stroke, heart attack and premature death. Erectile dysfunction usually occurs one to five years before there are overt signs of cardiovascular disease. Hence the importance of seeking medical help for erectile dysfunction.

Prescription drugs are a common cause of erectile dysfunction. Changing the prescription may solve the problem.

Psychotherapy and counselling are needed to overcome psychological erectile dysfunction. Hypnotherapy can be particularly useful in the management of this condition.

Oral medications may be indicated. These include:

  • Viagra (sildenafil) 1998
  • Cialis (tadalafil) 2003
  • Levitra (vardenafil) 2005

All three are PDE5 inhibitors, and they work by relaxing the blood vessels of the penis, allowing blood to flow into it, causing an erection. They are not aphrodisiacs and do not increase sexual desire. For them to be effective, sexual stimulation (foreplay) is required. They also cause other blood vessels to dilate, possibly causing flushing and/or headache.

Other possible treatments that your specialist physician may consider include:

  • External vacuum devices to create blood flow
  • Injections directly into the penis. These include papaverine (Pavabid, Vasal) and alprostadil (Caverject), both being vasodilators giving increased blood flow into the penis
  • Penile prosthetic implants
  • Hormone therapy.

Natural Ways to Overcome Erectile Dysfunction

In addition to the treatments outlined above, the following should be an essential and integral part of the management of erectile dysfunction.


Exercise, particularly aerobic exercise, is an effective treatment. One Harvard study showed that 30 minutes walking a day was linked to a 41% drop in the risk for erectile dysfunction.

Healthy eating

In the Massachusetts Male Aging Study, eating a diet rich in fruit, vegetables, whole grains and fish, with fewer red and processed meats and refined grains, decreased the likelihood of erectile dysfunction.

Vascular Health

High blood pressure, high blood sugar, high cholesterol and triglycerides can damage arteries in the heart (causing a heart attack), in the brain (causing stroke) and in the penis (causing erectile dysfunction). If it is felt that there are vascular problems, a change in lifestyle is not only indicated but is essential - weight loss if BMI is > 25, better nutrition (towards vegetarian and 75-80% alkali-forming foods) and exercise.

Weight and Abdominal Girth

Obesity increases the risk for vascular disease and diabetes, two major causes of erectile dysfunction.

Desirable weight is a BMI of less than 25 (weight in kilograms divided by height in meters squared). Overweight is 25-30 BMI, and obesity is >30 BMI. We are currently in an epidemic of overweight/obesity.

Abdominal Girth BMI Health Risk in Men
Very high>120>47>30
Very low<80<31.5<20

Research has shown that a man with a 107cm (42inch) waist is 50% more likely to have erectile dysfunction than one with a 81cm (32inch) waist. [American College of Sports Medicine (2005)]

A trim waist line is also a good defence against erectile dysfunction.

Pelvic Floor Exercises

A strong pelvic floor enhances rigidity during erections, and helps keep blood from leaving the penis by pressing on a key vein.

Kegel pelvic floor exercises are strongly recommended (see

Smoking and Alcohol

Stop smoking!

Limit alcohol to no more than 16 standard drinks per week. (See my September 2012 newsletter What is a Standard Drink?)


The initial approach in the management of erectile dysfunction should be to identify the cause, and then carryout the appropriate treatment.

If there is no obvious cause for the erectile dysfunction, and even if one or more causes are identified, the Natural Ways to Overcome Erectile Dysfunction set out above should be carried out, and may well be all that is needed. Of course, identified physical disorders must also be treated. It is also strongly recommended that the "natural ways" be embraced, as they are preventive as well as therapeutic.

Drugs Associated with Sexual Dysfunction

All drugs have potential side effects.

The list of those resulting in sexual dysfunction is significant. The link between a prescribed medication and sexual dysfunction (decreased desire, decreased arousal and/or orgasmic or ejaculatory difficulties) is often not recognised.

The following table sets out a list of drugs (prescribed medications) that are known to, and reported to, cause sexual dysfunction. It is reproduced from Australian Prescriber (published by NPS MedicineWise, an independent publication, Volume 36: Number 2: April 2013).

The drug names set out below are the generic form (or chemical name). 'Generic' is a term referring to the chemical name of the drug. All drugs are marketed under a trade (proprietary or brand) name. Once the patent expires on a drug (after 17-20 years), or if the drug has never held a patent, it can be marketed by another company or even several companies other than the original one, with a new trade name for the same generic substance. In fact, some drugs have several brand names.

Drugs associated with sexual dysfunction.

Drug ClassDecreased DesireDecreased ArousalOrgasm or
clonipramine CitalopramClomipramine
imipramine DoxepinEscitalopram
paroxetine Nortriptyline
sertraline sertraline**
Other Psychotropic DrugsAlprazolamChlorpromazineAlprazolam
Cardiovascular DrugsClonidinebeta blockers
hydrochlorothiazide Digixin
methyldopa hydrochlorothiazide
spironolactone Methyldopa
Other DrugscimetidineAntihisaminesNaproxen
gonadotrophin-releasing hormone agonists

**common cause of orgasmic difficulty.

The complete article by Helen M Conaglen and John V Conaglen, Drug-induced sexual dysfunction in men and women (Aust. prescr. 2013; 36: 42-5) can be accessed via


*Copyright 2013: The Huntly Centre.

Disclaimer: All material in the website is provided for informational or educational purposes only. Consult a health professional regarding the applicability of any opinions or recommendations expressed herein, with respect to your symptoms or medical condition.


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