Updated: November 29, 2007

An editing error in Suzi Godson’s sex column below, which has now been corrected, said that Viagra was free for patients over 60. Medicine treatments for erectile dysfunction are available on the NHS only if you have a specific medical condition or if it is causing severe distress.

Q I’m 70 and I bought some Viagra online. While I can achieve an erection, I have difficulty ejaculating. Could my high blood pressure be the problem?

DR THOMAS STUTTAFORD

A Congratulations on mastering the internet and still being potent, even if you do need help from Viagra. But I wouldn’t advise buying it or any other drug on the internet. Much of the counterfeit Viagra sold is made in developing countries and its quality is not guaranteed.

Viagra, Cialis and Levitra are potent drugs that affect arteries all over the body, as well as those leading to the penis. For this reason they could be dangerous if not produced to the high standard demanded by the quality control departments at Pfizer, Lilly or Bayer.

As Shakespeare said, tissues, organs and bodily functions all degenerate with age. Our skin loses its elasticity, the heart muscle deteriorates, guts don’t absorb nutrients so well and muscles shrink.

Our penises are no exception. Their nerve supply, even without disease – or the surgery to cure it – deteriorates. By the age of 70 more than 50 per cent of men are impotent, and by 75 the majority hasn’t had a spontaneous erection with a regular partner for 20 years.

Viagra and similar preparations seem like wonder drugs to many older men, but they affect erectile function rather than ejaculation or libido. The nerve supply to the male genitalia that controls ejaculation is through the sympathetic system, which is responsible for acts as an accelerator. Conversely, erections are controlled by the parasympathetic nervous system, which acts as a brake.

Libido is controlled by several parts of the brain, another example of the truism that sex is as much about what happens between the ears as between the legs. Treatment you are having for your high blood pressure could well affect your ejaculatory powers.

Discuss this with your doctor as there are several different, but equally good, schedules of medication to treat high blood pressure and some affect neither your ejaculatory nor erectile systems. Your doctor will know what drugs you are taking and whether they interact with Viagra.

Viagra was the first of the drugs to treat impotence and, therefore, its action is less effectively targeted on the genitalia. It dilates the penile arteries, which increases the blood supply to the penis and causes it to engorge.

Viagra’s power to dilate arteries also increases the blood flow through the retina so that vision may acquire a pink hue, and blood can accumulate in the limbs, temporarily taking it away from the brain, leaving patients feeling dizzy. The drop in blood pressure may also affect the coronary circulation.

Viagra and the others are not recommended for people who have had a stroke or heart attack recently, anyone with uncontrollable cardiac arrhythmias, taking nitrates for anginal pain, or who have a heart conduction system that results in the impulse controlling the beat being slower than usual. Nor should it be taken by patients suffering from some eye problems.

One unexpected side-effect is that concentrated grapefruit juice delays the metabolism of Viagra and similar drugs. So lovers taking Viagra should leave the grapefruit juice alone.

Dr Thomas Stuttaford, The Times doctor, spent many years working in a genitourinary clinic

SUZI GODSON

A Why didn’t you go to see your GP? Mixing prescription medicines for high blood pressure and erectile dysfunction without proper medical guidance is dumb, particularly as you have no guarantee that you are getting the real deal when you buy online. According to the Centre for Medicine in the Public Interest, worldwide counterfeit sales of Viagra are increasing by 13 per cent annually.

In the past, the main problem with counterfeit medications was that they didn’t contain enough, or even any, active ingredients to actually work. However, investigations by the drugs company Pfizer and regulatory bodies have found traces of boric acid, leaded motorway paint, floor polish, heavy metals, arsenic and even brick dust in counterfeit Viagra. And there is no way of tracing how, or where, the pills are made. Another Pfizer-led investigation into an online pharmacy claiming to be based in Canada found that the site’s domain name was hosted in Korea, but an order on the website came from an address that turned out to be a vacant piece of land.

It is just too easy to buy prescription medicines on the internet. Search under “buy Viagra” on Google and you get 1,030,000 results from UK pages alone. The first company that comes up on UK pages is www.have.co.uk. It sells something called “the little blue pill” and promises rock-hard erections, but it doesn’t say Pfizer on it, which is probably why it is selling eight little blue pills for £14.95, without offering medical advice or providing health warnings.

The next company on the list is www.online-clinic.co.uk. Its site explains what erectile dysfunction is and suggests that 85 per cent of all such dysfunction is treatable with either Viagra, Levitra or Cialis, which, needless to say, it offers for sale. The Online Clinic says that it is “the UK’s first legal, online clinic for impotence, hair loss and obesity”, and because it boasts qualified and experienced UK doctors and 100 per cent genuine medication from the UK, I checked in for a free consultation. I used my husband’s name and completed the questionnaire. I said “no” when asked if I had tried any treatments and received an e-mail saying: “Dear Tim, thanks for completing the consultation at www. onlineclinic.co.uk. Taking into account the information you have provided, I diagnose that you are suffering from the symptoms of impotence.” Two clicks later I am offered the chance to buy four 25mg Viagra pills for £74.95. Good value if you have sex four times a year, but a survey of more than 3,000 US adults aged 57 to 85, carried out last year by the National Social Life, Health and Ageing Project, Chicago, found that more than half to three quarters of respondents were still sexually active, though elderly men reported significantly more sexual activity than women thanks to treatments for erectile dysfunction.

Among the oldest age group, 54 per cent of those who were sexually active reported having sex at least two to three times a month, and 23 per cent reported having sex once a week or more. That works out at about £900 a year for online Viagra, but a GP’s prescription for the same number of tablets would cost less than £200.

Suzi Godson is author of The Sex Book (Cassell, £16.99) and The Body Bible (Penguin, £16.99)

timesonline.co.uk/love Just log on for more sex advice from Dr Thomas Stuttaford and Suzi Godson

E-mail your sexual dilemmas to body&soul@thetimes.co.uk or write to Body&Soul, The Times, 1 Pennington Street, London E98 1TT

Times recommends

• Live chat: Thrifty ways to update your winter wardrobe
• Is anybody out there really listening?
• Nutrition Q&A: Will eating late make me fat?