Precautions to keep in mind
It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly and to check for unwanted effects.
It is also important that your doctor does a blood test to check your liver function before you start bosentan and each month after that.
Do not use hormone-based birth control (pills, injections, patches, and implants) as your only method of birth control while you are taking this medicine.
In addition, check with your doctor immediately if you experience dark urine, light colored stools, loss of appetite, nausea and vomiting, unusual tiredness, yellow eyes or skin, fever with or without chills, or stomach pain.