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Generic name: treprostinil (oral) [ tre-PROS-ti-nil ]
Drug class: Agents for pulmonary hypertension

Medically reviewed by Philip Thornton, DipPharm. Last updated on Aug 22, 2023.

What is Orenitram?

Orenitram is used in adults to treat certain kinds of pulmonary arterial hypertension (PAH; high blood pressure in the vessels carrying blood to the lungs, causing shortness of breath, dizziness, and tiredness).

Orenitram may improve the ability to exercise and slow the worsening of symptoms in patients with PAH.

Orenitram belongs to a class of medications called vasodilators. Treprostinil works by relaxing the blood vessels, including those in the lungs, and improving blood flow.


You should not use Orenitram if you have severe liver disease.

You should not stop taking Orenitram suddenly. Your condition may get worse if you stop taking this medicine.

Before taking this medicine

You should not use Orenitram if you are allergic to treprostinil, or if you have severe liver disease.

To make sure Orenitram is safe for you, tell your doctor if you have ever had:

It is not known if treprostinil will harm an unborn baby. However, having high lung blood pressure during pregnancy may cause complications or medical problems in both mother and baby. The benefit of treating pulmonary hypertension may outweigh any risks to the baby.

Ask a doctor if it is safe to breastfeed while using Orenitram.

How should I take Orenitram?

Take Orenitram as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.

Take with food.

Swallow the tablet whole and do not crush, chew, or break it. Do not use a cracked or broken tablet.

Orenitram is usually taken 2 to 3 times per day. Follow your doctor's instructions. Your dose may change if you have side effects.

Use this medicine regularly for the best results.

Your dose needs may change if you switch to a different brand, strength, or form of this medicine. Avoid medication errors by using only the medicine your doctor prescribes.

You should not stop taking Orenitram suddenly. Your condition may get worse if you stop taking this medicine. Follow your doctor's instructions about tapering your dose.

Part of a tablet shell may appear in your stool but this will not make the medicine less effective.

Store at room temperature away from moisture and heat.

Dosing Information

Usual Adult Dose for Pulmonary Hypertension:

Extended-release tablets:
-Initial dose: 0.25 mg orally every 12 hours or 0.125 mg every 8 hours
-Maintenance dose: Titrate to the highest tolerated dose in increments of 0.25 or 0.5 mg twice a day or 0.125 mg 3 times a day every 3 to 4 days

-If dose increments are not tolerated, consider titrating slower.
-Appropriate maintenance dose determined by tolerability.
-If intolerable effects occur, decrease the dose in increments of 0.25 mg to avoid abrupt discontinuation.
-When discontinuing use, reduce the dose in steps of 0.5 to 1 mg per day.

Use: For the treatment of PAH (WHO Group 1) to improve exercise capacity

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.

Call your doctor for instructions if you miss 2 or more doses of Orenitram.

What happens if I overdose?

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

What should I avoid while taking Orenitram?

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

Orenitram side effects

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

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

  • chest pain, trouble breathing, tiredness, pale skin, swelling in arms or legs; or

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

Common Orenitram side effects may include:

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 Orenitram?

Tell your doctor about all your other medicines, especially:

This list is not complete. Other drugs may interact with treprostinil, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.


Active ingredient: treprostinil diolamine
Inactive ingredients: xylitol, maltodextrin, sodium lauryl sulfate, magnesium stearate, cellulose acetate, triethyl citrate, polyvinyl alcohol, titanium dioxide, polyethylene glycol, and talc. In addition, tablets may contain colorants FD& C Blue #2, iron oxide yellow, and iron oxide red. The imprint ink contains shellac glaze, ethanol, isopropyl alcohol, iron oxide black, n-butyl alcohol, and propylene glycol.


United Therapeutics Corp:, Research Triangle Park, NC 27709, USA.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Orenitram only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.