Bosentan needs a blood test every month to check your liver. It must never be used in pregnancy, so reliable birth control and monthly pregnancy tests are required.
Bosentan blocks a natural body chemical (endothelin) that tightens blood vessels. It is approved to reduce the number of new finger ulcers in people with systemic sclerosis who keep getting them, and it is used the same way in myositis-overlap patients with repeated finger ulcers. It prevents new ulcers rather than healing ones you already have.
Cuts down how many new ulcers you get.
Taken by mouth.
Useful when blood-vessel-relaxing medicines are not enough.
Good evidence in systemic sclerosis.
Your doctor chose this because the likely benefits outweigh the risks for you. Here is the honest, full picture.
Bosentan can affect the liver, so you have a liver blood test every month. It causes serious birth defects, so you must not be pregnant. You need reliable birth control (hormonal birth control alone may not be enough) and a pregnancy test every month.
Bosentan must not be used in pregnancy, because it causes serious birth defects. Reliable birth control and a monthly pregnancy test are required while you take it. Tell your doctor at once if you might be pregnant.
This guide is for learning, not medical advice. Myositis care is different for everyone, and many of these medicines are used based on specialist experience rather than a formal Canadian myositis approval. Never start, stop, or change a medicine without your own doctor. Your doses are decided with your care team at the Centre.