Product Distribution

United Therapeutics has contracted with a limited distribution network of authorized specialty distributors and wholesalers. ASSIST works with Specialty Pharmacies (SPs) to help deliver your medicines. SPs can dispense United Therapeutics medicines to your home or to the office of your healthcare provider (HCP). SP nursing services will coordinate treatment with you when therapy begins.

Referral Process

referral sent
  1. Referral is sent to SP
collects information
  1. SP collects missing information, performs benefit investigation
sp calls
  1. SP calls qualifying patient with benefit summary, reviews financial assistance, refers to Hub if needed
financial assistance
  1. Hub reviews financial assistance needs, notifies SP of outcome
  1. SP calls patient, confirms coverage and assistance with patient and insurance, and schedules shipment and nursing services

Tyvaso Specialty Pharmacy Network


You can call ASSIST at 1-877-864-8437, Monday - Friday, 8:30am to 7:00pm ET or email ASSIST at


TYVASO (treprostinil) Inhalation Solution and TYVASO DPI (treprostinil) Inhalation Powder are prescription medicines used in adults to treat:

  • Pulmonary arterial hypertension (PAH; WHO Group 1), which is high blood pressure in the arteries of your lungs. TYVASO or TYVASO DPI can improve the ability to exercise. Your ability to exercise decreases 4 hours after taking TYVASO or TYVASO DPI. It is not known if TYVASO or TYVASO DPI is safe and effective in children under 18 years of age.
  • Pulmonary hypertension associated with interstitial lung disease (PH-ILD; WHO Group 3), which is high blood pressure in the lungs due to inflammation and sometimes scarring in the lungs. TYVASO or TYVASO DPI can improve the ability to exercise.


Before you take TYVASO or TYVASO DPI, tell your healthcare provider about all of your medical conditions, including if you:

  • Have low blood pressure
  • Have or have had bleeding problems
  • Have asthma or chronic obstructive pulmonary disease (COPD)
  •  Are pregnant or plan to become pregnant. It is not known if either product will harm your unborn baby.
  • Are breastfeeding or plan to breastfeed. It is not known if either product passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby during treatment.

Tell your healthcare provider about all of the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Either product and other medicines may affect each other.

Especially tell your healthcare provider if you take:

  • Medicines used to treat high blood pressure or heart disease
  • Medicines that decrease blood clotting (anticoagulants)
  • Water pills (diuretics)
  • Gemfibrozil (Lopid®) or rifampin (Rimactane®, Rifadin®, Rifamate®, Rifater®)

What are the possible side effects of TYVASO or TYVASO DPI?

Both products can cause serious side effects, including:

  • Low blood pressure (symptomatic hypotension).If you have low blood pressure, either product may lower your blood pressure more.
  • Bleeding problems. Either product may increase the risk of bleeding, especially in people who take blood thinners (anticoagulants).

The most common side effects of both products are cough, headache, throat irritation and pain, nausea, reddening of the face and neck (flushing), fainting or loss of consciousness, dizziness, diarrhea, and shortness of breath. Like other inhaled prostaglandins, you may have trouble breathing after taking TYVASO or TYVASO DPI because it may cause the muscles around your airway to tighten (bronchospasm). These are not all the possible side effects. Call your doctor for medical advice about side effects or if you have trouble breathing.

You may report side effects to the FDA at or call 1-800-FDA-1088.

The risk information provided here is not comprehensive. To learn more about TYVASO or TYVASO DPI, talk with your healthcare provider. Please see Full Prescribing Information for TYVASO or TYVASO DPI, Instructions for Use manuals for TD-100 and TD-300 TYVASO® Inhalation System and TYVASO DPI™ Inhalation Powder, and additional information at or call 1-877-UNITHER (1-877-864-8437).