A medicine for high blood pressure in the lung arteries
Ambrisentan
A once-daily oral medicine that widens the lung arteries for pulmonary arterial hypertension, with less liver effect than bosentan.
What is Ambrisentan?
Ambrisentan is a once-a-day tablet used to treat pulmonary arterial hypertension, which is high blood pressure in the arteries of the lungs. Like bosentan, it is an endothelin receptor antagonist that relaxes and widens the lung arteries, easing breathlessness and helping you do more. It tends to affect the liver less than bosentan, but it can cause fluid retention and a fall in the blood count (anaemia). It can harm an unborn baby, so reliable contraception is essential. It is started and supervised by a specialist pulmonary hypertension centre.
Education and reference only. This is a plain-language guide to Ambrisentan — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Ambrisentan is an oral medicine for pulmonary arterial hypertension, a serious condition where the pressure in the arteries carrying blood from the heart to the lungs is too high. This strains the right side of the heart and causes breathlessness, tiredness and reduced activity. Ambrisentan is one of the endothelin receptor antagonists, taken once a day, and is prescribed only through specialist pulmonary hypertension services in the UK.
How it works
In pulmonary arterial hypertension a natural substance called endothelin makes the lung arteries tighten and narrow. Ambrisentan blocks the main receptor that endothelin acts on, allowing the lung arteries to relax and widen. This lowers the pressure the heart pumps against and can improve breathlessness and exercise capacity. It controls rather than cures the condition and is often used alongside other pulmonary hypertension treatments.
Company & origin
Originated / developed by: GlaxoSmithKline (originator).
An endothelin receptor antagonist used in the UK by specialist centres to treat pulmonary arterial hypertension.
Practical use
How to take Ambrisentan
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take one dose by mouth once a day, as directed by your pulmonary hypertension specialist, swallowed whole with water.
- Attend the blood tests your team arranges, including blood-count and liver checks.
- Use reliable contraception throughout treatment, as it can harm an unborn baby.
- Do not stop the medicine suddenly without specialist advice, and keep taking it even when you feel well.
- Report swelling of the ankles, increasing breathlessness, unusual tiredness or signs of anaemia to your team.
Weighing it up
Advantages & disadvantages of Ambrisentan
Advantages
- Taken just once a day by mouth, which is simple and convenient.
- Tends to affect the liver less than bosentan, so liver monitoring may be less intensive.
- Can ease breathlessness and improve exercise capacity in pulmonary arterial hypertension.
Disadvantages
- Can cause fluid retention with swollen ankles or legs.
- Can lower the blood count, causing anaemia and tiredness.
- Can harm an unborn baby, so reliable contraception is essential throughout treatment.
Practical use
Good to know
Ambrisentan is a specialist medicine, always started and monitored by a pulmonary hypertension centre. A practical advantage is that it tends to affect the liver less than bosentan, so routine liver checks may be less intensive, though your team will still monitor blood tests as they see fit. Its more common drawbacks are fluid retention (swollen ankles or legs) and a fall in the blood count, so weight, swelling and blood counts are reviewed. Like other medicines in its group, it can harm a developing baby, so it must not be used in pregnancy and effective contraception is essential throughout treatment and for a time afterwards. It is taken just once a day, which many people find convenient.
Who should not take it / use with caution
- Women who are pregnant, or who could become pregnant without reliable contraception, must not take it because it can harm the baby.
- People with significant liver disease or certain abnormal liver blood tests are usually not started on it.
- It is used with caution, and only under specialist guidance, in people with significant anaemia or fluid overload.
Monitoring
- Blood-count checks to watch for anaemia, and liver blood tests as the team advises.
- Review of fluid retention, weight and ankle swelling.
- Regular specialist review of breathlessness, walking distance and overall response.
Side effects
- Fluid retention with swollen ankles or legs, headache and flushing are common.
- A fall in the blood count (anaemia), with tiredness.
- Nasal congestion, palpitations and, less often, low blood pressure.
Key interactions
- Can harm an unborn baby, so it is part of a careful contraception plan.
- Levels can be affected by some other medicines, such as ciclosporin, so the specialist team coordinates these.
- Used alongside other pulmonary hypertension medicines under specialist supervision.
Available as: Tablets taken by mouth.
Answers
Ambrisentan: frequently asked questions
How is ambrisentan different from bosentan?
Both widen the lung arteries, but ambrisentan is taken once a day and tends to affect the liver less, though it can cause fluid retention and a fall in the blood count.
Can I take it if I might become pregnant?
No. It can harm an unborn baby, so it must not be used in pregnancy and reliable contraception is essential throughout treatment.
Why are my ankles swollen?
Ambrisentan can cause fluid retention, leading to swollen ankles or legs; tell your specialist team so it can be assessed and managed.
Will I still need blood tests?
Yes. Your team will check your blood count and liver as they see fit, even though liver monitoring may be less intensive than with bosentan.
Does it cure pulmonary hypertension?
No, it controls the condition by relaxing and widening the lung arteries, which can ease breathlessness and improve what you can do.
Authoritative sources
- BNF
- NICE CKS
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