Nearly every primary care physician, internist and geriatrician now understand that many older men retain an interest in sexual activity as they age. Some primary care physicians think that sexual potency in older men is the norm, and that if it is lacking, it is ‘all in the head.’ This viewpoint has not been supported by current literature. The Massachusetts Male Aging Study (MMAS) found that 52% of men between 40 and 70 years old reported having some form of erectile dysfunction (ED).1 The reality is that ED is a natural part of ageing and that the prevalence increases with age. In the MMAS, they found that roughly 50% of men at 50 years old, 60% of men at 60 years old and 70% of men at 70 years old had ED. Thus, nearly all men who live long enough should develop ED. The myths that surround the problems of impotence or ED confound the attempts of patients to receive treatment and the attempts of physicians to help them.1
In prescribing sildenafil, a doctor considers the age, general health status, and other medication(s) the patient is taking. The usual starting dose for most men is 50 mg, however, the doctor may increase or decrease the dose depending on side effects and effectiveness. The maximum recommended dose is 100 mg every 24 hours. However, many men will need 100 mg of sildenafil for optimal effectiveness, and some doctors are recommending 100 mg as the starting dose.
Nerve or spinal cord damage: Damage to the spinal cord and nerves in the pelvis can cause erectile dysfunction. Nerve damage can be due to disease, trauma, or surgical procedures. Examples include injury to the spinal cord from automobile accidents, injury to the pelvic nerves from prostate surgery for cancer (prostatectomy), and some surgeries for colorectal cancer, radiation to the prostate, surgery for benign prostatic enlargement, multiple sclerosis (a neurological disease with the potential to cause widespread damage to nerves), and long-term diabetes mellitus.
One study examined the role of testosterone supplementation in hypogonadal men with ED. These men were considered nonresponders to sildenafil, and their erections were monitored by assessing nocturnal penile tumescence (NPT). After these men were given testosterone transdermally for 6 months, the number of NPTs increased, as did the maximum rigidity with sildenafil.  This study suggests that a certain level of testosterone may be necessary for PDE5 inhibitors to function properly.
It is important to understand that ED is frequently, if not usually, directly related to endothelial dysfunction, and that the release of NO by the vasculature of the penile arteries is directly related to the function of intact, healthy endothelium. In the face of endothelial dysfunction, the process of erection fails to occur in a normal fashion.16
Erectile dysfunation medications may not be suitable for you if you have been told not to have sex, not to engage in sexual activity/actions that widen your blood vessels, have low blood pressure (hypotension), have recently had a stroke, have unstable angina, have had a heart attack or have a history of non-arteritic anterior ischaemic optic neuropathy. Men with cardiovascular disease/anatomical issue with their penis/priapism/taking long-lasting alpha-blockers should use with caution and discuss with a doctor first. Do not mix with drugs/medications containing nitrates.
A physical exam checks your total health. Examination focusing on your genitals (penis and testicles) is often done to check for ED. Based on your age and risk factors, the exam may also focus on your heart and blood system: heart, peripheral pulses and blood pressure. Based on your age and family history your doctor may do a rectal exam to check the prostate. These tests are not painful. Most patients do not need a lot of testing before starting treatment.