A trial is under way to investigate whether a one-off jab of Botox can improve symptoms of erectile dysfunction for men with diabetes – who tend to be less responsive to standard treatments for the condition.
Erectile dysfunction (ED), the inability to achieve and maintain an erection, affects half of men aged between 40 and 70 to some degree.
The causes include a narrowing of the blood vessels supplying the penis, which can be associated with heart disease and high cholesterol.
Men with diabetes are more at risk of ED as their bodies are unable to control blood sugar levels effectively – raised blood sugar levels can damage the blood vessels and nerves that help produce an erection.
Viagra-type drugs (known as PDE5 inhibitors) treat ED by increasing levels of nitric oxide, which widens blood vessels to allow better blood flow. The effects last up to four hours.
Erectile dysfunction affects half of men aged between 40 and 70 to some degree
But while they help in around 70 per cent of cases, they’re not suitable for men taking nitrates (medication for angina), for example, or those who have liver problems, or who have recently had a stroke.
Men on the new trial include those with severe ED or those for whom the Viagra-type drugs have not worked.
Botulinum toxin (the active compound found in Botox jabs) blocks signals from nerves that make muscles contract.
Previous research had suggested that it may help with ED as it relaxes the muscles around the blood vessels supplying the penis, helping improve blood flow.
It also prevents the release of norepinephrine, a chemical messenger that reduces blood flow.
The 32 men on the new trial will have a single injection of botulinum toxin and then take a pill containing 5mg tadalafil, a PDE5 inhibitor, daily for three months.
This follows a recent trial of 216 men, most of whom had not responded to Viagra-like drugs. At the start of this trial the men had been given two Botox injections, one into each of the two spongy chambers that run along the length of the penis and fill with blood to create an erection (numbing creams or gels were applied first).
After the first injection there was a meaningful improvement in 85 per cent of men with mild ED, 79 per cent of those with moderate ED and 64 per cent of those with severe ED.
Over the next six years, further injections were carried out on request – the response rate increased as it was repeated (it’s unclear why).
Among those with mild and moderate ED, there was an overall 50 per cent improvement at the end of the trial, while there was a near threefold improvement in those with severe disease, reported the researchers from Poincare University Hospital in France, writing in the journal Toxins.
The results of the new trial, under way at Aswan University in Egypt, are expected next year.
Commenting on the study, Professor Raj Persad, a consultant urologist at Bristol Urology Associates, said: ‘Using Botox would seem attractive as, although it involves an injection into the penis on each side, it avoids the cumbersomeness of using vacuum erection devices, which themselves may not work, or pharmacological agents that need to be injected before every sexual encounter.
‘If the trial results are verified in everyday clinical practice, this approach may add greater flexibility for the treatment of erectile dysfunction.’
Men whose diets are rich in vitamin B6 – found in foods such as fish, chickpeas and fortified cereal – are less likely to have erectile dysfunction (ED), reports the journal Translational Andrology and Urology.
Analysis of data from 3,875 men found that those who consumed the highest levels of the vitamin had a 23 per cent lower risk of ED (other B vitamins also reduced the risk). It’s thought B vitamins reduce levels of homocysteine, an amino acid that can damage arteries, reducing blood flow.
