This medication is used to treat a type of high blood pressure in the lungs (pulmonary arterial hypertension). Treprostinil helps to improve symptoms such as shortness of breath and tiredness. It works by relaxing and widening the blood vessels (arteries) in the lungs and other parts of the body so that blood can flow more easily. This medication belongs to a class of drugs known as vasodilators.

When you first start using this medication, it must be given by a health care professional in a hospital or clinic. This medication is given as a continuous injection, usually under the skin using an infusion pump. If you cannot receive the drug under the skin, it may be mixed with an IV solution and given into a vein using an infusion pump. The dosage is based on your medical condition, weight, and response to treatment. Your doctor may direct you to use other medications in addition to treprostinil to treat your condition and to prevent problems. Use all prescribed medications exactly as directed.

Your health care professional will prepare and mix the solution for you according to the manufacturer's instructions. If you are using this medication at home, learn all preparation and usage instructions from your health care professional. Before using, check this product for particles or discoloration. If either is present, do not use the liquid, and contact your health care professional right away. Learn how to store and discard medical supplies safely.

Do not suddenly decrease the dose or suddenly stop using this medication because doing either may lead to serious (rarely fatal) worsening of your condition. If you must stop this medication, gradually reduce the dose as directed by your doctor. Consult your doctor right away if your infusion is interrupted or if you develop worsening trouble breathing, dizziness, or weakness. To avoid interruptions in drug treatment, you should have a backup infusion pump and infusion sets available in case your equipment fails. Consult your health care professional for more information.

Tell your doctor if your condition does not get better or if it gets worse.

Nausea, vomiting, diarrhea, headache, dizziness, jaw pain, flushing, loss of appetite, weakness, abdominal pain, and redness/swelling/pain at the injection site may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• new/worsening swelling of the arms/legs
• mental/mood changes (such as restlessness, nervousness)
• unusual bleeding/bruising

To avoid infection, follow your health care professional's instructions for proper handling of this medication. Tell your doctor right away if you develop any signs of infection (such as fever, chills).

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before using treprostinil, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• liver problems
• bleeding problems

This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: severe dizziness, fainting.

Do not share this medication with others.

Lab and/or medical tests (such as blood pressure) may be done while you are using this medication. Keep all medical and lab appointments. Consult your doctor for more details.

This drug is to be given continuously as an infusion. If your infusion is interrupted, contact your doctor or pharmacist right away.

Store unopened vials at room temperature. Consult your pharmacist for details about the storage of opened vials and prepared solutions. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).