Ambrisan 5

Indications

Ambrisentan is used to treat pulmonary arterial hypertension (PAH), a serious condition in which the blood pressure in the arteries of the lungs is too high, making the right side of the heart work harder. It improves the ability to exercise and slows the worsening of symptoms such as breathlessness and tiredness. It may be used alone or together with Tadalafil. Treatment is started and supervised by a specialist.

How It Works

Endothelin-1 is a natural substance that narrows blood vessels and causes them to thicken. Ambrisentan blocks endothelin type A receptors in the lung blood vessels. This lets the vessels relax and widen, lowering the pressure in the lungs and reducing the strain on the heart.

Dosage and Administration

Take exactly as prescribed by your specialist, usually once a day, with or without food, at about the same time each day. The starting dose is often 5 mg, which the doctor may increase. Swallow the tablet whole; do not split, crush or chew it. Do not stop treatment without medical advice.

Interactions

• Ciclosporin raises ambrisentan levels; the dose of ambrisentan is limited when they are used together.
• Rifampicin may change ambrisentan levels at the start of treatment; your doctor will monitor you.
• Other medicines that lower blood pressure can add to its effect.
• Tell your doctor about all medicines, including herbal products.

Contraindications

• Pregnancy, and women who could become pregnant and are not using reliable contraception.
• Breastfeeding.
• Idiopathic pulmonary fibrosis (scarring of the lungs of unknown cause), with or without pulmonary hypertension.
• Severe liver disease, or liver enzymes more than 3 times the upper normal limit.
• Allergy to ambrisentan or soya (some tablets contain soya lecithin).

Side Effects

Common effects include swelling of the legs and ankles (fluid retention), headache, blocked or runny nose, sinus problems, flushing, dizziness, palpitations, tiredness, nausea and a fall in red blood cells (anaemia).

Get urgent medical help if you have rapidly increasing swelling or weight gain, worsening breathlessness, chest pain, fainting, yellowing of the skin or eyes, dark urine with severe tiredness, or signs of a serious allergic reaction.

Pregnancy and Lactation

Ambrisentan can cause serious birth defects and must not be taken during pregnancy. Women who can become pregnant must have a negative pregnancy test before starting and regularly during treatment (usually monthly), and must use reliable contraception during treatment and for 1 month after stopping. Tell your doctor at once if you think you may be pregnant. Do not breastfeed while taking it.

Precautions and Warnings

• Your doctor will check your blood count and liver tests before and during treatment.
• It may reduce sperm count in men; discuss family planning with your doctor.
• Dizziness may affect driving.
• If fluid in the lungs develops, your doctor may check for a rare condition called pulmonary veno-occlusive disease.

Overdose

Overdose may cause headache, flushing, dizziness, nausea, nasal congestion and low blood pressure. Get medical help promptly.

Therapeutic Class

Endothelin receptor antagonist (pulmonary arterial hypertension treatment).

Storage

Store below 30°C in a dry place, away from light. Keep out of the reach of children.