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04 February 2020

By Dr Wendy Winnall - Scientific writer for PCFA.

Surgery to remove a prostate tumour can have devastating effects on a man’s ability to have sex. Many men try devices and medications such as Viagra to help them have sex after surgery. This week’s research blog discusses the help available to achieve erections and the latest research comparing erection medications.

Surgery for prostate cancer reduces erections

Treatment for localised prostate cancer can have terrible consequences for a man’s sex life. Soon after surgery, most men find that achieving and maintaining an erection is difficult. For some men, this gradually improves over 12 months or more. Unfortunately, many have long term problems having sex. Radiotherapy for prostate cancer can also affect a man’s sex life, but these effects are usually delayed.

It’s believed that these issues are caused by damage occurring during surgery. Damage to the nerves and blood supply to the penis and surrounding tissue reduces erections. The nerves connecting to the penis are very close to the prostate gland. So surgery in this area can easily affect them. Even if nerve-sparing surgery is performed, the nerves need to be separated from the prostate in order to remove the gland. This causes damage through bruising and inflammation. Over time, this damage can heal, leading to improvements for some men.

The ability to have an erection is not the only issue for men after prostate surgery. Other problems include infertility, penis shortening, lack of orgasm and loss of urine during orgasm. This research blog addresses the ability to form an erection, while other issues have been discussed in previous articles.

Men having treatment with hormone therapy (androgen deprivation therapy, ADT) will have more issues than the inability to get an erection. Hormone therapy also affects a man’s desire for sex.

Improving erections

Unfortunately there are no miracle cures for erection problems. But there are medications and devices that can help. Some men experience improvements after trying these methods, but others report no luck with them. All these erections treatments have potential side effects. Your doctor or Prostate Cancer Specialist Nurse can help you choose an appropriate method and apply this safely. A sexual therapist can also offer professional assistance. More information about help improving erections is available from PCFA.

Vacuum erection devices

A vacuum erection device helps draw blood into the penis to stimulate an erection by creating a negative pressure. A trial involving 109 volunteers showed that the vacuum erection device helped about a third of men achieve erections after surgery.

Penile rings

These can be used by men who can achieve an erection but can’t maintain it long enough. The rings are made of rubber and are placed onto the base of the penis.

PDE5 inhibitors (Viagra, Cialis, Levitra and Spedra)

Drugs known as PDE5 inhibitors are tablets used to treat erection problems. They relax the smooth muscles cells lining the blood vessels in the penis. This increases blood flow to the penis. They don’t work for every man. It depends on the nature of the damage that is preventing erections. Common PDE5 inhibitors are Viagra (sildenafil), Cialis (tadalafil), Levitra (vardenafil) and Spedra (Avanafil). Large clinical trials have provided evidence that these drugs are safe and effective, resulting in their approval for use in Australia.

Caverject injections (Alprostadil)

Alprostadil is a drug that is injected into the penis to induce erections. Clinical trials have shown this treatment helps men achieve erections after prostate surgery. Like any medication, Alprostadil has potential side effects.

Penile implants

A penile implant is generally used when all else has failed. Surgery is required to insert the implants. They are used to form a “mechanical erection”. The spongy tissue that runs along each side of the penis is removed and the implants are placed there.

Penile rehabilitation

Penile rehabilitation is a treatment program for preventing ongoing erection problems. The aim is to improve a man’s chances of returning to typical erections. Penile rehabilitation stimulates a regular blood supply to the penis, starting soon after surgery. This is believed to protect the penis tissue from low oxygen and promote the gradual recovery of normal erections. A previous research blog has addressed the ongoing controversy – does penile rehabilitation actually work?

A new trial comparing Spedra to Viagra

Treatments to improve erections are far from perfect. The best way to improvement is through research. An important part of this research is comparing the different medications and asking the men who take them how well they are working.  

A new study from Italy has compared Spedra with Viagra. Spedra (Avanafil) is a relatively new medication available in Australia. Spedra is very similar to Viagra, Cialis and Levitra. These drugs all act on a protein called PDE5 (phosphodiesterase type 5). Spedra is considered a second generation PDE5 inhibitor. It inhibits this protein more selectively, meaning it may be less likely to have side effects.

The Italian study asked whether there were any differences in the benefits and side effects for men taking Spedra compared to Viagra after prostate surgery. 160 men joined the trial. They took medication for 6 months after their nerve-sparing prostate surgery to help their erections. Half the men took Spedra and half took Viagra.

The men joining this trial were less than 70 years old and had relatively good erections before surgery. They started taking the medication 10 days after surgery, when catheters were removed. The tablets were taken at least 30 mins before attempting sex and a maximum of three were taken each week.

After six months of treatment, the men were asked how well it was working via survey questions. Most of their answers showed that the medications were equally effective in producing erections. Viagra was slightly more effective for two counts: erection hardness and “how often erections were hard enough for penetration”.

Fewer men taking Spedra had side effects. 5% of men taking Spedra had side effects compared to 20% of men taking Viagra. These side effects included headaches and hot flushes with both drugs. Some of the men taking Viagra experienced muscle pain and indigestion. One of these men also experienced a condition called cyanopsia – where everything looks blue-tinted. 

This study has shown that Spedra may not be quite as effective as Viagra, but the side effects may be easier to manage. A larger randomised controlled trial will be needed to confirm these findings.

NOTE: You should not take PDE5 inhibitors if you are also taking medications in the nitrates group, which are used for chest pain or prevention of chest pain. These nitrates can be given as tablets, sprays or patches. Discuss your medical conditions and current medications with your doctor.

Erectile dysfunction PDE5 inhibitor medications should only be used with a doctor’s prescription and under medical supervision.

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