What is iloprost?

Iloprost is a man-made form of a substance called prostacyclin which is produced naturally in the body. Iloprost is used to improve blood flow in people with severe circulatory problems.

Epoprostenol is another form of prostacyclin, used by some doctors for the same reasons and in the same way. The information in these pages refers to both iloprost and epoprostenol.


Iloprost or epoprostenol may be prescribed if you have ulcers of the fingers resulting from systemic sclerosis (scleroderma) or related conditions. They may also be used for severe Raynaud's phenomenon or when there is gangrene due to very poor circulation.

Iloprost improves the circulation of the blood by:

  • opening up the blood vessels, which helps them to carry more blood to all areas of the body
  • reducing clumping of the red cells in the blood, which reduces the tendency of the blood to clot
  • helping to prevent or repair damage to blood vessels.

Iloprost usually starts to work immediately, although it can sometimes take up to six weeks.

If you've been suffering with very cold hands or feet they may feel warmer straight away. Ulcers may begin to improve within a few days.

Iloprost's beneficial effects may carry on for weeks and sometimes even months after the infusion.

Usually, iloprost is prescribed if other drugs such as nifedipine haven't worked for you. Your doctor will discuss other treatment options with you if need be.

How is it taken and how long does it take to work?

Iloprost is given through a drip (infusion) into your arm, usually continuously for about six hours a day for 3–5 days in a row in hospital or a clinic. It can sometimes be given continuously over 24 hours.

In some hospitals you stay on the ward for the three to five days and in others you attend the day-case unit during the day and go home in the evenings.

The infusion will be started at a low dose and then increased gradually to make sure you can tolerate the higher doses. If you develop side-effects, your dose will generally be reduced again.

The rate at which iloprost is given depends on your weight, but can also be adjusted if you have side-effects.

Sometimes longer-term or continuous prostacyclin is prescribed, for example in people with pulmonary hypertension (a condition sometimes associated with scleroderma that leads to raised pressure in the arteries supplying the lungs).

Iloprost usually starts to work immediately, although it can sometimes take up to six weeks.

Side-effects and risks

The main side-effects of iloprost are:

  • facial flushing
  • headaches
  • a fall in blood pressure – therefore your blood pressure will be carefully monitored during your treatment.

Less common side-effects include:

  • nausea (feeling sick)
  • vomiting
  • diarrhoea
  • muscle cramps
  • pain in the jaw.

Paracetamol and an anti-sickness drug can be given if you experience side-effects. All side-effects disappear very quickly once the iloprost infusion is stopped or reduced.

If you have any concerns about your treatment or its side-effects you should discuss these with your doctor, rheumatology nurse or pharmacist.

Effects on other treatments

You can take all your usual medications before and after a course of iloprost. However, during a course of iloprost, your doctor will probably recommend that you don't take certain other medications which also widen the blood vessels or lower blood pressure.

When you go to the hospital on the first day, take a list of all your medications with you. Your doctor will tell you whether you should leave out any medications on the days when you're having an infusion.


Iloprost doesn't affect vaccinations, so you can have them before or after a course of iloprost treatment. In the unlikely event that you need a vaccination during a course of iloprost, your specialist will advise you.


There's no particular reason to avoid alcohol before or after a course of iloprost treatment. However, in the evenings after your infusions you should limit your alcohol intake as it may make the side-effects of iloprost worse.

Fertility, pregnancy and breastfeeding

We don't know whether iloprost has any effect on fertility. Current guidelines state that iloprost will only be prescribed to pregnant women in special circumstances if their disease is severe.

If you're pregnant or planning to start a family you should tell your doctor before you start the treatment.

There is no research on use of this drug in breastfeeding so it's probably best avoided while on iloprost.