How Do PAH Prostacyclin Analogs Work?

PAH prostacyclin analogs are medications used to treat pulmonary arterial hypertension (PAH), a condition of high blood pressure in the arteries that carry deoxygenated blood from the heart to the lungs. PAH prostacyclin analogs are synthetic forms of prostacyclin, a natural substance produced in the body.

Prostacyclin, also known as prostaglandin I2 (PGI2), is produced by the endothelial cells that form the inner lining of blood vessels. Prostacyclin dilates blood vessels and improves blood flow by preventing the proliferation of vascular smooth muscle cells, and prevents blood clotting by inhibiting platelet aggregation.

Patients with PAH tend to have reduced levels of prostacyclin which leads to blood vessel constriction and hypertension. PAH prostacyclin analogs supplement the requirement and mimic the action of natural prostacyclin to reduce pulmonary hypertension and reduce associated symptoms.

PAH prostacyclin analogs may be administered through any of the following routes:

• Oral tablets
• Oral inhalations
• Intravenous (IV) or subcutaneous infusions

PAH prostacyclin analogs are used to diminish symptoms, delay disease progression and improve exercise ability in the following conditions:

FDA-approved:

• Pulmonary hypertension: High blood pressure in the lungs due to any cause.
• Pulmonary arterial hypertension: A group of chronic diseases that thicken and narrow the pulmonary arteries leading to high blood pressure in the pulmonary arteries.
• Pulmonary arterial hypertension associated with ILD: Interstitial lung disease (ILD) is a condition that causes progressive scarring and damage to the lung tissue.

Orphan designation:

• Systemic sclerosis: A systemic autoimmune connective tissue disease.

Side effects of PAH prostacyclin analogs may include the following:

• Infusion site reactions and pain
• Flushing
• Jaw pain
• Headache
• Myalgia (muscle pain)
• Cough
• Diarrhea
• Nausea
• Vomiting
• Dyspepsia (indigestion)
• Throat irritation or pain
• Flu-like symptoms
• Trismus (lockjaw)
• Vasodilation
• Hypersensitive reactions such as:
  • Eczema
  • Rash
  • Urticaria (hives)
  • Pruritus (itching)
  • Angioedema (swelling in the tissue under the skin or mucous membranes)
• Edema
• Cellulitis
• Anxiety
• Nervousness
• Restlessness
• Insomnia
• Dizziness
• Hypotension (low blood pressure)
• Syncope (fainting)
• Palpitations
• Tachycardia (rapid heartbeat)
• Supraventricular tachycardia (rapid heartbeat that starts in the heart region above the ventricles)
• Back pain
• Bone pain
• Muscle cramps/spasms
• Arthralgia (joint pain)
• Pain in extremities
• Tongue pain
• An elevated level of the enzyme gamma-glutamyl transferase (GGT)
• Hemoptysis (coughing up blood)
• Pneumonia
• Musculoskeletal pain
• Hyperesthesia (increased sensitivity)
• Bronchospasm
• Thrombophlebitis (inflammation of a vein with clots) associated with peripheral IV infusion
• Hemorrhage
• Thrombocytopenia (low platelet count in the blood)
• Anemia (low red blood cell count)
• Pancytopenia (low count of all types of blood cells)
• Pulmonary embolism (blood clot in the lungs)
• Kidney failure
• Liver failure
• Hypersplenism (overactive spleen)
• Splenomegaly (enlarged spleen)
• Hyperthyroidism
• High output cardiac failure

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of PAH prostacyclin analog drugs include:

• epoprostenol
• Flolan
• iloprost
• Orenitram
• Remodulin
• treprostinil
• treprostinil inhaled
• treprostinil SC (pending FDA approval)
• Trevyent (pending FDA approval)
• Tyvaso
• Veletri
• Ventavis