Mar-Bosentan: Uses, Side Effects and Dosage

ABOUT THIS MEDICATION

What the medication is used for:

Mar-BOSENTAN (bosentan) tablets are prescribed for the treatment of pulmonary arterial hypertension (high blood pressure in the blood vessels between the heart and the lungs).

What it does:

Mar-BOSENTAN reduces abnormally high blood pressure by relaxing these blood vessels. Mar-BOSENTAN tablets belong to the class of medicines known as endothelin receptor antagonists.

Before you take Mar-BOSENTAN:

Tests your doctor will do before treatment:

• a blood test for liver function;
• a blood test for anemia (reduction in red blood cells);
• a pregnancy test.

When it should not be used:

Do not use Mar-BOSENTAN if you:

• are hypersensitive (allergic) to bosentan or any other ingredients

  in the tablet (See What the nonmedicinal ingredients are);

• have liver problems;
• are pregnant or planning to become pregnant (hormonal contraceptives alone are not effective when you take Mar- BOSENTAN);
• are a woman of childbearing age and not using adequate contraceptive methods;

• are being treated with cyclosporine A, or glyburide. Tell your doctor immediately if you are pregnant or plan to become pregnant in the near future. This is because Mar- BOSENTAN may harm your unborn baby and you must not take Mar-BOSENTAN if you are pregnant. You must also not become pregnant while taking Mar-BOSENTAN. If you are a woman of childbearing age, your doctor or gynecologist will advise you about adequate contraceptive methods while taking Mar- BOSENTAN. Because Mar-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). Monthly pregnancy tests are recommended while you are taking Mar-BOSENTAN and you are of childbearing age.

  Tell your doctor immediately if you are breastfeeding. You are advised to stop breastfeeding if Mar-BOSENTAN is prescribed for you because it is not known if this drug passes into the milk in women who are taking Mar-BOSENTAN.

  If you feel dizzy while taking Mar-BOSENTAN, do not drive or operate any tools or machines.

  Mar-BOSENTAN is not recommended for children.

What the medicinal ingredient is:

Bosentan monohydrate.

What the nonmedicinal ingredients are:

Maize starch, Magnesium stearate, povidone, pregelatinized starch, sodium starch glycolate and glyceryl behenate . The film-coating is composed of hydroxypropyl methylcellulose, ethylcellulose, talc, iron oxide red, iron oxide yellow, titanium dioxide and triacetin.

What dosage forms it comes in:

Tablets: 62.5 mg and 125 mg

WARNINGS AND PRECAUTIONS

Warnings and Precautions

Before you use Mar-BOSENTAN talk to your doctor or pharmacist if you are:

• known to have liver problems;

• pregnant or thinking of becoming pregnant;

• a woman of childbearing age and not using adequate contraceptive methods;
• breastfeeding;
• hypersensitive (allergic) to bosentan or any other ingredients of Mar-BOSENTAN.

Before starting Mar-BOSENTAN treatment, tell your doctor and your pharmacist if you are taking or have recently taken any other medicines, even those you have bought yourself. It is especially important to tell your doctor if you are taking:

• hormonal contraceptives (as these may not be effective as the sole method of contraception when you take Mar- BOSENTAN);
• glyburide (for diabetes);
• cyclosporine A (a medicine used after transplants and to treat psoriasis), or any other drugs used to prevent rejection of transplanted organs;
• fluconazole (to treat fungal infections);

• rifampicin (to treat tuberculosis).

  Tests during treatment:

  Some patients taking Mar-BOSENTAN were found to have abnormal liver function values (increase in liver enzymes) and some patients developed anemia (reduction in red blood cells). Because these findings may not cause symptoms you can feel or observe yourself, your doctor will do regular blood tests to assess any changes in your liver function and hemoglobin level.

Liver function:

This blood test will be done:

• every month or more frequently, if needed.

If you develop abnormal liver function, your doctor may decide to reduce your dose or stop treatment with Mar-BOSENTAN. When your blood test results for liver function return to normal, your doctor may decide to restart treatment with Mar-BOSENTAN.

Anemia:

This blood test will be done:

• after 1 month and after 3 months of treatment;
• every 3 months during treatment thereafter.

If you develop anemia, your doctor may decide to perform further tests to investigate the cause.

Your regular blood tests, both for liver function and anemia, are an important part of your treatment. We suggest you write in a diary the date of your most recent test and also that of your next test (ask your doctor for the date) to help you remember when your next test is due.

Pregnancy tests for women of childbearing age:

Due to the risk of failure of hormonal contraception when taking Mar-BOSENTAN and the risk in patients with pulmonary hypertension of rapid and severe deterioration of the disease, monthly pregnancy tests are recommended before and during treatment with Mar-BOSENTAN.

INTERACTIONS WITH THIS MEDICATION

Drugs that may interact with Mar-BOSENTAN include: warfarin, simvastatin and other statins, glyburide, ketoconazole, cyclosporine A, tacrolimus, sirolimus and hormonal contraceptives.

PROPER USE OF THIS MEDICATION

Always take Mar-BOSENTAN exactly as your doctor has instructed you. You should check with your doctor or pharmacist if you are unsure.

Usual dose:

The usual dose is one tablet, swallowed twice daily (morning and evening), consistently with or without food. For the first 4 weeks, you will take a 62.5 mg tablet twice daily, from then on, your doctor will advise you to take a 125 mg tablet twice daily, depending on how you react to Mar-BOSENTAN.

Overdose:

If you take more tablets than you have been told to take, see a doctor or go to a hospital immediately.

In case of drug overdose, contact a health care practitioner, hospital emergency department or regional Poison Control Center immediately, even if there are no symptoms.

Missed Dose:

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

Stopping treatment:

Suddenly stopping your treatment with Mar-BOSENTAN may lead to a worsening of your symptoms. Do not stop taking Mar- BOSENTAN unless your doctor tells you to. Your doctor may tell you to reduce the dose over a few days before stopping completely.

SIDE EFFECTS AND WHAT TO DO ABOUT THEM

Like all medicines, Mar-BOSENTAN can have side effects even when used as directed.

If you notice yellowing of the skin or eyes (jaundice) or other symptoms such as nausea, vomiting, fever, abdominal pain or unusual tiredness, see your doctor immediately because this may be related to abnormal liver function.

Headaches were the most common side effect in clinical studies.

You may also notice one or more of the following side effects

• flushed appearance, inflammation of the throat and nasal passages, swelling of the legs and ankles, or other signs of fluid retention, low blood pressure, irregular heartbeat, heartburn, tiredness, itching, nausea. If these side effects become bothersome, contact your doctor.

Other less common side effects that you might notice:

• vomiting, abdominal pain, diarrhea, skin rash.

If you notice any other side effects or signs of allergic reaction (e.g. swelling of the face or tongue, rash, pruritus) while you are taking Mar-BOSENTAN or if any of the side effects mentioned above worries you, please inform your doctor or pharmacist.

REPORTING SIDE EFFECTS

MORE INFORMATION

This document plus the full product monograph, prepared for health professionals can be obtained by contacting the sponsor, Marcan Pharmaceuticals Inc.

This is not a complete list of side effects. For any unexpected effects while taking Mar-BOSENTAN, contact your doctor or pharmacist.

HOW TO STORE IT

Marcan Pharmaceuticals Inc., 77 Auriga Drive, Unit# 4,

Ottawa, ON, Canada, K2E 7Z7.

Date of Preparation: May 12, 2014

Keep out of reach and sight of children. Store between 15ºC and 30ºC. Do not use after the expiry date stated on the label.