Medicines for erectile dysfunction in MS

MS can cause erectile dysfunction in men. This can be distressing and affect how men feel about themselves and intimate relationships. 

Medicines to treat erectile dysfunction have been available on the NHS since 1998. There are several related drugs called phosphodiesterase 5 (PDE-5) inhibitors which work in the same way. These drugs temporarily increase the blood flow to your penis when you get sexually excited. They can be provided without restriction by GPs to people affected by erectile dysfunction. 

Alprostadil is an alternative to PDE-5 medicines that works by relaxing blood vessels in the penis to improve blood flow.

The first PDE-5 inhibitor to be licenced was sildenafil. This is sold as Viagra, Liberize, Aronix or Nipatra. Other drugs in this group include tadalafil (Cialis), vardenafil (Levitra) and avanalfil (Spedra). The choice of PDE-5 drug you are offered will depend on how often you are sexually active and whether you have tried any of the medications before.

Although all the PDE-5 drugs work in the same way, they have differences in how long they take to have an effect, how long they last, and whether they are affected by eating food. 

Alprostadil and PDE-5 drugs like Viagra (sildenafil) or Cialis (tadalafil) can be taken by men with MS and have been shown to work as expected.

You can read more about each drug in their Patient Information Leaflets.

Patient Information Leaflet: Viagra (sildenafil) 10mg

Patient Information Leaflet: Spedra (avanafil) 100mg

Patient Information Leaflet: Cialis (tadalafil) 10mg

Patient Information Leaflet: sildenafil (Boots generic)

Patient Information Leaflet: Levitra (vardenafil) 10mg

You can find Patient Information Leaflets for other formulations of PDE-5 inhibitors at the Electronic Medicine Compendium. Just type in the name of the drug to search.

All of the PDE-5 inhibiting drugs are provided as tablets and need to be taken some time before sexual activity. Sildenafil, vardenafil and avanafil work for about eight hours and they are designed to work within an hour after taking them and last for up to 10 hours. Tadalafil lasts for up to 36 hours and is more suitable if you require treatment for a longer period of time, for example, over a weekend. 

It may take longer to notice the effects if the tablet is taken with food, so it’s best to take it on an empty stomach. You can then eat after an hour without affecting the medicine. 

PDE-5 medications are triggered by sexual stimulation, so you need to be aroused for it to work.

You should only take one tablet within a 24-hour period.

If you have tried more than one type of PDE-5 medicine, but they have not worked for you, speak to your doctor. You may be offered other treatments such as  Alprostadil. 

Common side effects for PDE-5 inhibitors include

• headaches and migraines
• flushing (redness) 
• indigestion
• nausea (feeling sick)
• vomiting (being sick)
• a blocked or runny nose
• back pain
• vision disturbances
• muscle pain

You should not take a PDE5 inhibitor if you:

• are receiving treatment with drugs containing nitrates, such as those used to treat angina
• are using recreational drugs such as poppers (butryl nitrate)
• have serious heart disease
• have recently had a stroke
• have low blood pressure or uncontrolled high blood pressure.

If you have problems with liver or kidney function, have anatomical differences with your penis, or have cardiovascular disease, talk to your doctor before starting an erectile dysfunction medication.

• Sexual problems for men with MS
• Sex and MS: a guide for men - (book)
• Erectile dysfunction
• Sex and MS (Men): Breaking it down Our MS podcast with experts in men's sexual issues.