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Bosentan Zentiva 125 mg film-coated tablets – patient leaflet, side effects, dosage

Last updated: · Text from the MHRA, as of · About this document

Medicine status: No longer supplied Details

Medicine strength:
125 mg
Still supplied:
The same active substance, strength and form in the NHS Dictionary of Medicines and Devices (dm+d). Ask your pharmacist or doctor before changing to another make.
Contains active substance:
ATC code:

Patient leaflet - Bosentan Zentiva 125 mg film-coated tablets

1. WHAT BOSENTAN IS AND WHAT IT

IS USED FOR

The name of your medicine is Bosentan 62.5 mg film-coated tablets or Bosentan 125 mg film-coated tablets (called bosentan throughout this leaflet). Bosentan tablets contain bosentan, which blocks a naturally occurring hormone called endothelin-1 (ET-1), which causes blood vessels to narrow. Bosentan therefore causes blood vessels to expand and belongs to the class of medicines called “endothelin receptor antagonists”.

Bosentan is used to treat:

  • Pulmonary arterial hypertension (PAH): PAH is a disease of severe narrowing of the blood vessels in the lungs resulting in high blood pressure in the blood vessels (the pulmonary arteries) that carry blood from the heart to the lungs. This pressure reduces the amount of oxygen that can get into the blood in the lungs, making physical activity more difficult. Bosentan widens the pulmonary arteries, making it easier for the heart to pump blood through them. This lowers the blood pressure and relieves the symptoms.

Bosentan is used to treat patients with class III PAH to improve exercise capacity (the ability to carry out physical activity) and symptoms. The “class” reflects the seriousness of the disease: “class III” involves marked limitation of physical activity. Some improvements have also been shown in patients with class II PAH. “Class II” involves slight limitation of physical activity. The PAH for which bosentan is indicated can be:

  • primary (with no identified cause or familial).
  • caused by scleroderma (also called systemic sclerosis, a disease where there is abnormal growth of the connective tissue that supports the skin and other organs).
  • caused by congenital (inborn) heart defects with shunts (abnormal passageways) causing abnormal flow of blood through the heart and lungs.
  • Digital ulcers: (sores on the fingers and toes) in adult patients with a condition called scleroderma. Bosentan reduces the number of new finger and toe ulcers that appear.
  • WHAT YOU NEED TO KNOW

BEFORE YOU TAKE BOSENTAN

Do not take bosentan

  • if you are allergic to bosentan or any of the other ingredients of this medicine (listed in section 6).
  • if you have liver problems (ask your doctor).

    • if you are pregnant, or could get pregnant because you are not using reliable contraceptive methods. Please read the information under “Contraceptives” and “Other medicines and bosentan”.
    • if you are taking ciclosporin A (a medicine used after a transplant or to treat psoriasis).

If any of these apply to you, tell your doctor.

Warnings and precautions

Tests your doctor will do before treatment

  • a blood test to check your liver function.
  • a blood test to check for anaemia (low haemoglobin).
  • a pregnancy test if you are a woman of childbearing potential.

Some patients taking bosentan have been found to have abnormal liver function tests and anaemia (low haemoglobin). Tests your doctor will do during treatment

During treatment with bosentan, your doctor will arrange for regular blood tests to check for changes in your liver function and haemoglobin level.

For all these tests please refer also to the Patient Alert Card (inside your pack of bosentan tablets). It is important that you have these regular blood tests as long as you are taking bosentan. We suggest you write the date of your most recent test and also of your next test (ask your doctor for the date) on the Patient Alert Card, to help you remember when your next test is due.

Blood tests for liver function

These will be done every month for the duration of treatment with bosentan. After an increase in dose an additional test will be done after 2 weeks.

Blood tests for anaemia

These will be done every month for the first 4 months of treatment, then every 3 months after that, as patients taking bosentan may get anaemia.

If these results are abnormal, your doctor may decide to reduce your dose or stop treatment with bosentan and to perform

further tests to investigate the cause. Children and adolescents

Bosentan is not recommended in paediatric patients with systemic sclerosis and ongoing digital ulcer disease. Please see also section 3. How to take Bosentan. Other medicines and bosentan

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines, including medicines obtained without a prescription. It is especially important to tell your doctor if you are taking:

  • Ciclosporin A (a medicine used after transplants and to treat psoriasis), which must not be used together with bosentan.
  • Sirolimus or tacrolimus, which are medicines used after transplants, as these are not recommended to be used together with bosentan.
  • Glibenclamide (a diabetes medicine), rifampicin (a tuberculosis medicine), fluconazole (a medicine against fungal infections), ketoconazole (a medicine used to treat Cushing’s syndrome), or nevirapine (an HIV medicine) as these medicines are not recommended to be used together with bosentan.
  • Other medicines for the treatment of HIV infection, which may require special monitoring if used together with bosentan.
  • Hormonal contraceptives, which are not effective as the sole method of contraception when you take bosentan. Inside your pack of bosentan tablets you will find a Patient Alert Card which you should read carefully. Your doctor and/or gynaecologist will establish the contraception which is appropriate for you.
  • Other medications for the treatment of pulmonary hypertension: sildenafil and tadalafil.
  • Warfarin (an anticoagulant agent).
  • Simvastatin (used to treat

    hypercholesterolaemia).

Driving and using machines

Bosentan has no or negligible influence on the ability to drive and use machines. However, bosentan can induce

hypotension (decrease of your blood pressure) which can make you feel dizzy, affect your vision and affect your ability to drive and use machines. Therefore, if you feel dizzy or that your vision is blurred while taking bosentan, do not drive or operate any tools or machines.

Pregnancy, breast-feeding and fertility

If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking bosentan.

Women of childbearing age

Do NOT take bosentan if you are pregnant or planning to become pregnant. Pregnancy tests

Bosentan may harm unborn babies conceived before starting or during treatment. If you are a woman who could become pregnant, your doctor will ask you to take a pregnancy test before you start taking bosentan, and regularly while you are taking bosentan.

Contraceptives

If it is possible that you could become pregnant, use a reliable form of birth control (contraception) while you are taking bosentan. Your doctor or gynaecologist will advise you about reliable contraceptive methods while taking bosentan. Because bosentan may make hormonal contraception (e.g. oral, injection, implant, or skin patches) ineffective, this method on its own is not reliable. Therefore, if you use hormonal contraceptives you must also use a barrier method (e.g. female condom, diaphragm, contraceptive sponge, or your partner must also use a condom). Inside your pack of bosentan tablets you will find a Patient Alert Card. You should complete this card and take it to your doctor at your next visit so that your doctor or gynaecologist can assess whether you need additional or alternative reliable contraceptive methods. Monthly pregnancy tests are recommended while you are taking bosentan and are of childbearing age.

Tell your doctor immediately if you become pregnant while you are taking bosentan, or plan to become pregnant in the near future.

Breast-feeding

Bosentan passes into your breast milk. You are advised to stop breast-feeding if bosentan is prescribed for you, because it is not known if bosentan in breast milk can harm your baby. Talk to your doctor about this.

Fertility

If you are a man taking bosentan, it is possible that this medicine may lower your sperm count. It cannot be excluded that this may affect your ability to father a child. Talk to your doctor if you have any questions or concerns about this. Bosentan contains sodium

This medicine contains less than 1 mmol sodium (23 mg) per tablet, that is to say essentially “sodium-free”.

3. HOW TO TAKE BOSENTAN

Treatment with bosentan should only be started and monitored by a doctor who has experience in the treatment of PAH or systemic sclerosis. Always take this medicine exactly as your doctor has told you.

Check with your doctor or pharmacist if you are not sure.

Adults

The treatment in adults is usually started for the first 4 weeks with 62.5 mg twice daily (morning and evening), from then your doctor will usually advise you to take a 125 mg tablet twice daily, depending on how you react to bosentan.

Children and adolescents

The dose recommendation in children is only for PAH. For children aged 1 year and older, treatment with bosentan is usually started with 2 mg per kg bodyweight twice daily (morning and evening). Your doctor will advise you on your dosing. Bosentan should not be administered to children with a body weight below 31 kg, and an alternative product containing bosentan should be used.

If you have the impression that the effect of bosentan is too strong or too weak, talk to your doctor in order to find out whether your dose needs to be changed. How to take bosentan

Tablets should be taken (morning and evening), swallowed with water. The tablets can be taken with or without food. If you take more bosentan than you should

If you take more tablets than you have been told to take, contact your doctor immediately.

If you forget to take bosentan

If you forget to take bosentan, take a dose as soon as you remember, then continue to take your tablets at the usual times. Do not take a double dose to make up for forgotten tablets.

If you stop taking bosentan

Suddenly stopping your treatment with bosentan may lead to your symptoms getting worse. Do not stop taking bosentan unless your doctor tells you to. Your doctor may tell you to reduce the dose over a few days before stopping completely.

If you have any further questions on the use of this medicine, ask your doctor or pharmacist.

4. POSSIBLE SIDE EFFECTS

Like all medicines, this medicine can cause side effects, although not everybody gets them.

The most serious side effects with bosentan are:

Abnormal liver function which may affect more than 1 in 10 people.

Anaemia (low blood value) which may affect up to 1 in 10 people. Anaemia may occasionally require blood transfusion. Your liver and blood values will be monitored during treatment with bosentan (see section 2). It is important that you have these tests as ordered by your doctor.

Signs that your liver may not be working properly include:

º Nausea (urge to vomit).

º Vomiting.

º Fever (high temperature).

º Pain in your stomach (abdomen). º Jaundice (yellowing of your skin or the whites of your eyes).

º Dark-coloured urine.

º Itching of your skin.

º Lethargy or fatigue (unusual tiredness or exhaustion).

º Flu-like syndrome (joint and muscle pain with fever).

If you notice any of these signs tell your doctor immediately.

Other side effects:

Very common (may affect more than 1 in 10 people):

  • Headache.
  • Oedema (swelling of the legs and ankles or other signs of fluid retention). Common (may affect up to 1 in 10 people):
  • Flushed appearance or redness of skin.
  • Hypersensitivity reactions (including skin inflammation, itching and rash).
  • Gastroesophageal reflux disease (acid reflux).
  • Diarrhoea.
  • Syncope (fainting).
  • Palpitations (fast or irregular

    heartbeats).

  • Low blood pressure.
  • Nasal congestion.

Uncommon (may affect up to 1 in 100 people):

  • Thrombocytopenia (low number of blood platelets)
  • Neutropenia/leukopenia (low number of white blood cells)
  • Elevated liver function tests with hepatitis (inflammation of the liver) including possible exacerbation of underlying hepatitis and/or jaundice (yellowing of the skin or the whites of the eyes).

Rare (may affect up to 1 in 1,000 people):

  • Anaphylaxis (general allergic reaction), angioedema (swelling, most commonly around the eyes, lips, tongue or throat).
  • Cirrhosis (scarring) of the liver, liver failure (serious disturbance of liver function), autoimmune hepatitis (inflammation of the liver caused by the

    body’s own defence system attacking liver cells) which may occur even several months to years after initiation of treatment.

    Blurred vision has also been reported at an unknown frequency (frequency cannot be estimated from the available data). Side effects in children and

    adolescents

    The side effects that have been reported in children treated with bosentan are the same as those in adults.

    Reporting of side effects

    If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

    By reporting side effects, you can help provide more information on the safety of this medicine.

5. HOW TO STORE BOSENTAN

Keep this medicine out of the sight and reach of children.

Do not use this medicine after the expiry date which is stated on the carton and blister after EXP. The expiry date refers to the last day of that month.

Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.

This medicine does not require any special storage conditions.

6. CONTENTS OF THE PACK AND OTHER INFORMATION

What Bosentan film-coated tablets contain

The active substance is bosentan. Each film-coated tablet contains bosentan monohydrate equivalent to 62.5 mg of bosentan.

Each film-coated tablet contains bosentan monohydrate equivalent to 125 mg of bosentan.

The other ingredients are maize starch, povidone (K-30), sodium starch glycolate (type A), pregelatinized maize starch, glycerol dibehenate, magnesium stearate, opadry II 85F230061 orange (a mixture consisting of polyvinyl alcohol (E 1203), titanium dioxide (E 171), macrogol (E 1521), talc (E 553b), iron oxide yellow (E 172) and iron oxide red (E 172)). What Bosentan film-coated tablets look like and contents of the pack

Bosentan 62.5 mg film-coated tablets are round, biconvex-shaped, light orange coloured film-coated tablets with the diameter approx. 6.1 mm.

Bosentan 125 mg film-coated tablets are oval, biconvex-shaped, light orange coloured film-coated tablets with length approx. 11.1 mm and width approx. 5.1 mm.

Size of packing:

Bosentan 62.5 mg 14, 56 and 112 film-coated tablets.

Bosentan 125 mg 14, 56, 112 and 120 film-coated tablets.

Not all pack sizes may be marketed. Marketing Authorisation Holder and Manufacturer

Marketing Authorisation Holder

Zentiva Pharma UK Limited, 12 New Fetter Lane, London, EC4A 1JP, UK Manufacturer

ITC Production s.r.l.

Via Pontina KM 29

00071 Pomezia (Rome) – Italy

This leaflet was last updated in September 2025.

About this document

Source: MHRA - Medicines and Healthcare products Regulatory Agency (products.mhra.gov.uk) · Marketing authorisation: PL 17780/0610

Last revision stated in the text: September 2025 · MHRA data as of 13 October 2026

Found a mistake? Tell us on the contact page.

The information on this site does not replace the advice of a doctor or pharmacist.

Facts about Bosentan Zentiva 125 mg film-coated tablets

Active substance Bosentan
Strength 125 mg
Pharmaceutical form Oral tablet
Bosentan 125mg: oval, biconvex-shaped, light orange coloured film coated tablets with length approx. 11mm and width approx. 5mm.
How is it taken Oral
Excipients Core ingredients, Maize starch, Povidone, Sodium starch glycolate, Pregelatinized maize starch, Glycerol dibehenate, Magnesium stearate, Coating ingredients, Polyvinyl alcohol (E 1203), Titanium dioxide (E 171), Macrogol (E 1521), Talc (E 553b), Iron oxide yellow (E172), Iron oxide red (E172)
Is it available? No, all its packs are listed as discontinued (NHS Dictionary of Medicines and Devices – not a record of current supplies)
Shelf life 2 years
Storage This medicinal product does not require any special storage conditions.
Drug group (ATC) Antihypertensives, other antihypertensives
  1. C Cardiovascular system drugs
    1. C02 Antihypertensives
      1. C02K Other antihypertensives
        1. C02KX Antihypertensives for pulmonary arterial hypertension
          1. C02KX01 bosentan
Marketing authorisation PL 17780/0610 (first authorised 24 July 2013)
Marketing authorisation holder Zentiva Pharma UK Limited
Codes BNF 02050100

Sources: the MHRA product information (products.mhra.gov.uk) and the NHS Dictionary of Medicines and Devices (dm+d), release 10.1.0 of 12 October 2026, NHS Business Services Authority. Contains public sector information licensed under the Open Government Licence v3.0.