Treprostinil dilates (widens) the arteries and decreases the amount of blood clotting platelets in your body. These effects lower blood pressure in the pulmonary artery that leads from the heart to the lungs.

Treprostinil is used to treat pulmonary arterial hypertension (PAH). treprostinil improves your ability to exercise and can help prevent your condition from getting worse.

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

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed. You may need to use this medicine for many years.

You may receive your first dose in a hospital or clinic setting to quickly treat any serious side effects.

Treprostinil is given around the clock using an infusion pump attached to a catheter placed under your skin (subcutaneous) or into a vein (intravenous). A healthcare provider can teach you how to properly use the infusion pump by yourself.

Read and carefully follow any Instructions for Use provided with your medicine. Do not use treprostinil if you don't understand all instructions for proper use. Ask your doctor or pharmacist if you have questions.

You may need to mix treprostinil with a liquid (diluent). When using injections by yourself, be sure you understand how to properly mix and store the medicine.

Prepare your injection only when you are ready to give it. Do not use if the medicine has changed colors or has particles in it. Call your pharmacist for new medicine.

Call your doctor if your symptoms do not improve, or if they get worse.

You should not reduce your dose or stop using treprostinil suddenly. Stopping suddenly may make your condition worse.

To make sure there is no interruption in your treatment, you may need to have a back-up infusion pump, replacement batteries, and extra infusion sets. Get your prescription refilled before you run out of medicine completely.

Store unopened vials (bottles) of treprostinil at room temperature away from moisture and heat. Throw away a vial after 30 days of use, even if there is still medicine left inside.

After mixing your medicine, you will need to use it within a certain number of hours or days. This will depend on the type of diluent used, and whether you store the mixture at room temperature or in a refrigerator. Carefully follow the mixing and storage instructions provided with your medicine. Ask your pharmacist if you have questions.

Use a needle and syringe only once and then place them in a puncture-proof "sharps" container. Follow state or local laws about how to dispose of this container. Keep it out of the reach of children and pets.

You should not use treprostinil if you are allergic to it.

Tell your doctor if you have ever had:

• liver disease; or

• kidney disease.

Do not start or stop using treprostinil during pregnancy without your doctor's advice. It is important to properly control PAH during pregnancy because having this condition can harm both mother and baby. Tell your doctor right away if you become pregnant.

It may not be safe to breast-feed while using treprostinil. Ask your doctor about any risk.

Because treprostinil is given around the clock, you should not miss a dose if you use the medicine properly. Call your doctor right away if your treprostinil therapy is interrupted for any reason.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include severe tingling or warmth under your skin, diarrhea, vomiting, or fainting.

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

An intravenous catheter may increase your risk of a serious infection called sepsis. If you use intravenous treprostinil, watch for symptoms such as: fever, flu symptoms, mouth and throat ulcers, rapid heart rate, or rapid and shallow breathing. Call your doctor right away if you have any of these conditions.

Treprostinil may cause serious side effects. Call your doctor at once if you have:

• pain, swelling, redness, bleeding, or a hard lump where your catheter is placed;

• swelling in your hands or feet;

• a light-headed feeling, like you might pass out; or

• worsening PAH symptoms (tiredness, pale skin, chest pain, trouble breathing).

Common side effects of treprostinil may include:

• pain, redness, bleeding, bruising, or swelling around the catheter;

• headache, jaw pain;

• diarrhea, nausea; or

• flushing (warmth, redness or tingling).

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.

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Other drugs may affect treprostinil, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.