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.
Using this medicine while you are pregnant can cause very serious birth defects. Use two forms of effective birth control to keep from getting pregnant while you are using this medicine (even if the medicine is temporarily stopped), and for at least one month after you stop taking the medicine. The most effective forms of birth control are hormone birth control pills, patches, shots, vaginal rings, or implants, an IUD, or a vasectomy (for men). One of these forms of birth control should be combined with a condom, a diaphragm, or a cervical cap. If a woman has had a tubal ligation, she does not need to use a second form of birth control. If you think you have become pregnant while using this medicine, tell your doctor right away.
You must have a negative pregnancy test before you will be allowed to take this medicine. You will also be required to have a pregnancy test every month during your treatment. If you miss a period while you are using this medicine, tell your doctor right away.
Liver problems may occur while you are using this medicine. Stop using this medicine and check with your doctor right away if you are having more than one of these symptoms: dark urine, fever with or without chills, light colored stools, loss of appetite, nausea and vomiting, skin rash, stomach pain, unusual tiredness, or yellow eyes or skin.
Bosentan may decrease the amount of sperm men make and affect their ability to have children. If you plan to have children, talk with your doctor before using this medicine.
This medicine may cause fluid retention (edema) in some patients. Check with your doctor right away if you are gaining weight rapidly; have swelling in your hands, ankles, feet, or all over the body; or if you have trouble with breathing while you are using this medicine.
Pulmonary edema may occur while using this medicine. Stop using this medicine and check with your doctor right away if you have chest pain; difficult, fast, noisy breathing, sometimes with wheezing; blue lips and fingernails; pale skin; increased sweating; coughing that sometimes produces a pink frothy sputum; or shortness of breath.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.