Sildenafil for pulmonary hypertension

This leaflet is about the use of sildenafil for pulmonary hypertension.

Information Standard quality markThis leaflet has been written specifically about the use of this medicine in children. The information may differ from that provided by the manufacturer. Please read this leaflet carefully. Keep it somewhere safe so that you can read it again.

Name of drug

Sildenafil
Brand names: Viagra®, Revatio®

Why is it important to take this medicine?

Pulmonary hypertension means high blood pressure in the lungs, which often occurs after heart surgery. Taking sildenafil will reduce the blood pressure in the lungs, so that they can work properly. Sometimes babies on ventilators need it in the neonatal unit.

What is sildenafil available as?

  • Tablets: 20 mg (white, these contain small amounts of lactose), 25 mg, 50 mg, 100 mg (blue)
  • Liquid medicine can be ordered specially from your pharmacist (e.g. 50 mg in 5 mL)

When should I give sildenafil?

  • Sildenafil is usually given four times a day. This is usually first thing in the morning, at about midday, late in the afternoon and at bedtime. Ideally, these times should be about 4 hours apart (e.g. 8 am, midday, 4 pm, 8 pm).
  • Sildenafil is sometimes given three times a day. This should be once in the morning, once in the early afternoon and once in the evening. Ideally, these times are at least 6 hours apart, for example 8 am, 2 pm and 8 pm.

Give the medicine at about the same times each day so that this becomes part of your child’s daily routine, which will help you remember.

How much should I give?

Your doctor will work out the amount of sildenafil (the dose) that is right for your child. The dose will be shown on the medicine label.

Your doctor may suggest that your child has a low dose to start with. They may then increase the dose as your child gets used to the medicine and depending on how your child
responds to it.

It is important that you follow your doctor’s instructions about how much to give.

How should I give it?

TabletsTablets should be swallowed with a glass of water, milk or juice. Your child should not chew the tablet.

Dissolving a tabletYou can dissolve the tablet in a small glass of water and then add some strong-flavoured drink (e.g. blackcurrant squash) to hide the taste. Your child should drink it all straight away. Then add some more water or squash to the glass, swirl it round and ask your child to drink it. This makes sure they get all the medicine.

You can crush the tablet and mix it with a small amount of soft food such as yogurt, honey or jam. Make sure your child swallows it straight away, without chewing.

Liquid medicine with oral syringeLiquid medicine: measure out the right amount using an oral syringe or medicine spoon. You can get these from your pharmacist. Do not use
a kitchen teaspoon as it will not give the right amount.

When should the medicine start working?

Your child will usually start taking the medicine while in hospital. It will start to work within a few days, although you may not notice any difference in your child. Your doctor will check that it is working.

What if my child is sick (vomits)?

  • If your child is sick less than 30 minutes after having a dose of sildenafil, give them the same dose again.
  • If your child is sick more than 30 minutes after having a dose of sildenafil you do not need to give them another dose. Wait until the next normal dose.

What if I forget to give it?

Do not give the missed dose. Just give the next dose as usual.

Never give a double dose of sildenafil.

What if I give too much?

You are unlikely to do harm if you give an extra dose of sildenafil by mistake, although your child may have more side-effects.

If you are concerned that you may have given your child too much sildenafil, contact your doctor or NHS Direct (0845 4647 in England and Wales; 08454 24 24 24 in Scotland). Have the medicine or packaging with you if you telephone for advice.

Are there any possible side-effects?

We use medicines to make our children better, but sometimes they have other effects that we don’t want (side-effects).

  • Your child may feel dizzy or light-headed when they stand up, or may faint. Encourage them to stand up slowly, and to sit or lie down if they feel dizzy or lightheaded. If this happens too often, contact your doctor to check your child’s blood pressure, as it may be too low.
  • Your child’s hair may become thinner and some may fall out. It should grow back when the medicine is stopped.

Your child may get some of the following side-effects when they first start taking sildenafil. They are usually mild and should usually wear off after a few days as your child gets used to the medicine. If they are still a problem after 2 weeks, or you are worried, contact your doctor, but continue to give sildenafil.

  • They may get a headache, feel tired or become easily breathless.
  • Your child’s eyesight may become blurry or double and their eyes may become red and painful or sensitive to bright light.
  • They may get mild indigestion or stomach pain, or may feel sick (nausea) or be sick (vomit).
  • They may have a dry mouth. Eating citrus fruits (e.g. oranges) and taking sips of water may help.

There may, sometimes, be other side-effects that are not listed above. If you notice anything unusual and are concerned, contact your doctor.

Can other medicines be given at the same time as sildenafil?

  • You can give your child medicines that contain paracetamol or ibuprofen, unless your doctor has told you not to.
  • Sildenafil should not be taken with some medicines that you get on prescription. Tell your doctor and pharmacist about any other medicines that your child is taking
  • before giving sildenafil.
  • Check with your doctor or pharmacist before giving any other medicines to your child. This includes herbal or complementary medicines.

Is there anything else I need to know about this medicine?

  • Do not suddenly stop giving sildenafil to your child as their symptoms may come back.
  • The liquid medicine does not keep for long once it has been opened. Write the date that you start it on the bottle and make sure you do not keep it past the expiry date given on the bottle.
  • You may have heard that Viagra (which is one of the brands for sildenafil) is used to treat erectile dysfunction (impotence). However, your child will be taking a much lower dose of it for pulmonary hypertension. Sildenafil may cause erections but this is rare and is nothing to worry about.

General advice about medicines

  • Try to give medicines at about the same times each day, to help you remember.
  • If you are not sure a medicine is working, contact your doctor but continue to give the medicine as usual in the meantime. Do not give any extra doses, as you may do
  • harm.
  • Only give sildenafil to your child. Never give it to anyone else, even if their condition appears to be the same, as this could do harm.
  • If you think someone else may have taken the medicine by accident, contact your doctor.
  • Make sure that you always have enough medicine. Order a new prescription at least 2 weeks before you will run out (longer for liquid medicine).
  • Make sure that the medicine you have at home has not reached the ‘best before’ or ‘use by’ date on the packaging. Give old medicines to your pharmacist to dispose of.

Where I should keep this medicine?

  • Keep the medicine in a cupboard, away from heat and direct sunlight. It does not need to be kept in the fridge.
  • Make sure that children cannot see or reach the medicine.
  • Keep the medicine in the container it came in.

Who to contact for more information

Your doctor, pharmacist or nurse will be able to give you more information about sildenafil and about other medicines used to treat pulmonary hypertension.


You can also get useful information from:


Publication Date

30/1/2012

Copyright Disclaimer

Version 1, January 2012. © NPPG, RCPCH and WellChild 2011, all rights reserved. Reviewed by: January 2014.
The primary source for the information in this leaflet is the British National Formulary for Children. For details on any other sources used for this leaflet, please contact us through
our website, www.medicinesforchildren.org.uk
We take great care to make sure that the information in this leaflet is correct and up-to-date. However, medicines can be used in different ways for different patients. It is
important that you ask the advice of your doctor or pharmacist if you are not sure about something. This leaflet is about the use of these medicines in the UK, and may not apply
to other countries. The Royal College of Paediatrics and Child Health (RCPCH), the Neonatal and Paediatric Pharmacists Group (NPPG), WellChild and the contributors and
editors cannot be held responsible for the accuracy of information, omissions of information, or any actions that may be taken as a consequence of reading this leaflet.