bosentan

What is the most important information I should know about bosentan?

Certain other medicines can interact with bosentan and should not be used at the same time. Tell your doctor about all your current medicines.

Bosentan is available only from a certified pharmacy under a special program.

What is bosentan?

Bosentan lowers blood pressure in your lungs, helping your heart pump blood more efficiently.

Bosentan is used to treat pulmonary arterial hypertension (PAH) in adults and children who are at least 3 years old. It improves your ability to exercise and prevents your condition from getting worse.

Bosentan is available only under a special program from a certified pharmacy. You must be registered in the program and understand the risks and benefits of taking this medication.

Bosentan may also be used for purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking bosentan?

Some medicines can cause unwanted or dangerous effects when used with bosentan. Your doctor may change your treatment plan if you also use:

• cyclosporine; or
• glyburide.

Tell your doctor if you have ever had:

• liver disease;
• fluid retention;
• diabetes;
• an autoimmune disorder such as rheumatoid arthritis or psoriasis; or
• a heart or kidney transplant.

You will need to have a negative pregnancy test before starting this treatment. You will be re-tested every month during your treatment, and 1 month after you stop taking this medicine.

Even if you are not planning a pregnancy, you are considered able to become pregnant if:

• you have entered puberty (even if you have not yet started having periods);
• you have never had a hysterectomy or had your ovaries removed; or
• you have not gone through menopause (you have never gone 12 months in a row without a menstrual period).

While taking bosentan and for at least 30 days after your last dose, you must use a highly effective form of birth control or two methods together.

• A tubal ligation alone is an effective birth control method.
• An intrauterine device (IUD) alone is also an effective birth control method.
• If you use birth control pills, implants, injections, skin patches, or vaginal rings, you must use a back-up barrier form of birth control, such as a condom or diaphragm or cervical cap. Always use a spermicide gel or insert together with a barrier form of birth control.
• If you use only a barrier method, you must use a second barrier method as a back-up. For example, use a diaphragm or cervical cap in addition to a condom, plus a spermicide gel or insert.
• If your sexual partner has had a vasectomy, you must still use a second method of birth control--either a barrier method or a hormonal form (birth control pills, injections, skin patch, or vaginal ring).

Bosentan comes with patient instructions about acceptable forms of birth control to use while taking this medicine. Follow these directions carefully. Ask your doctor or pharmacist if you have any questions.

If you are the parent or caregiver of a female child taking this medicine, talk to the child's doctor once you notice any signs of puberty (breast development or pubic hair), even if menstrual periods have not yet begun.

Bosentan can decrease sperm count and may affect fertility in men (your ability to have children).

How should I take bosentan?

Bosentan is usually taken 2 times per day. Your doctor may change your dose after 4 weeks of treatment. Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

You may take bosentan with or without food.

Do not swallow a dispersible tablet whole. Place it into a small amount of water and allow the tablet to disperse in the liquid. The tablet will not dissolve completely. Stir gently and drink this mixture right away.

If your doctor tells you to use only half of a dispersible tablet, break the tablet at the line scored on it and disperse only one tablet half in water. Place the unused tablet half back into the blister pack for storage, and use that half within 7 days. Do not break a tablet half into smaller pieces.

Your blood cells may also need to be tested during treatment and for up to 3 months after you stop taking this medicine.

You should not stop using bosentan suddenly. Stopping suddenly may make your condition worse. Follow your doctor's instructions about tapering your dose.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

What should I avoid while using bosentan?

What are the possible side effects of bosentan?

• swelling in your legs or ankles, with or without weight gain;
• a light-headed feeling, like you might pass out;
• low red blood cells (anemia) --pale skin, unusual tiredness, feeling light-headed or short of breath, cold hands and feet;
• liver problems --nausea, vomiting, fever, upper stomach pain, tiredness, dark urine, jaundice (yellowing of the skin or eyes); or
• new lung problems --anxiety, sweating, pale skin, severe shortness of breath, wheezing, gasping for breath, cough with foamy mucus, chest pain, fast or uneven heart rate.

Common side effects may include:

• headache, joint pain;
• low blood pressure, fainting;
• flushing (warmth, redness, or tingly feeling);
• irregular heartbeats; or
• cold symptoms such as stuffy nose, sinus pain, sneezing, sore throat.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect bosentan?

Tell your doctor about all your other medicines, especially:

• rifampin;
• tacrolimus;
• warfarin (Coumadin, Jantoven);
• antifungal medication --fluconazole, itraconazole, ketoconazole, voriconazole;
• HIV/AIDS medication that contains ritonavir --Norvir, Kaletra, Technivie, Viekira, and others;
• hormonal forms of birth control --birth control pills, injections, skin patches, or implants; or
• "statin" medicine to treat high cholesterol --Crestor, Lipitor, Mevacor, Pravachol, Vytorin, Zocor, and others.

This list is not complete and many other drugs may affect bosentan. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Where can I get more information?

Your pharmacist can provide more information about bosentan.