Targeted medications for pulmonary hypertension are the result of years of research and development, including clinical trials with patients. These treatments work by addressing chemical imbalances in the lungs.
Changes in body chemistry can have a profound impact on overall health. A chemical balance change affects how cells communicate with each other. That imbalance can cause cells and organs to react abnormally.
For those living with PH, four chemical families or pathways are known to be abnormal in the blood vessels of the lungs. The abnormalities contribute to PH by causing the blood vessels in the lungs to tighten.
PH-targeted medications help blood vessels relax, so blood flows more easily through them to the lungs. They work by modifying the chemical imbalance in the four pathways or biological mechanisms that contribute to the development and progression of PH.
Targeted medical therapies can be administered in four different ways.
Current PH treatments listed below are oral (tablets) unless specified. Each drug is linked to a treatment page that includes drug-specific funding sources. Treatments are listed alphabetically by brand name followed by the generic name.
Patients may be prescribed two or more targeted therapies.
Activin signaling inhibitors counteract overgrowth of smooth muscle in the blood vessels of the lungs. Smooth muscle cells are present throughout the body, including in the lining of many blood vessels. Activin is a protein that can cause smooth muscle cells to increase in number. Some people with PH have too much activin signaling, which overproduces smooth muscle cells in the pulmonary arteries. Overproduction causes blood vessels to narrow. Activin signaling inhibitors help re-balance activin signaling so smooth muscle cells proliferate appropriately.
This pathway is characterized by too much endothelin-1. Endothelin receptor antagonists help prevent blood vessels from narrowing.Endothelin is a family of chemicals made by the cells in the innermost layer of the blood vessels. Endothelin tells the blood vessels to relax or tighten. One form of endothelin, called ET-1, tells the blood vessels to tighten by binding to a specific receptor on a nearby cell’s surface. One way to think of this is to consider ET-1 as a key and the ET receptor as a lock. Many people with PH make too much ET-1. Endothelin receptor antagonists block the ET receptors from being unlocked by ET-1, which decreases ET-1 effects, allowing blood vessels to relax and widen.
This pathway is characterized by too little nitric oxide. Soluble guanylate cyclase stimulators increase stimulation of the sGC enzyme and increase sensitization to another chemical (nitric oxide) to relax the blood vessels in the lungs.
Nitric oxide acts as a “key” for an enzyme “lock” called soluble guanylyl cyclase. Cyclic GMP is important because it helps blood vessels relax. It is broken down by another enzyme called phosphodiesterase type-5. Many people with PH don’t have enough nitric oxide to fuel cGMP production.
Think of sGC as a factory that produces a chemical called cyclic GMP.
Endothelin receptor antagonist combined with PDE5
Both medications in this single-dose tablet decrease blood pressure in lung arteries but in different ways.
Prostacyclin is produced by the innermost layer of blood vessels. It helps those blood vessels relax and widen. Many PH patients don’t make enough prostacyclin.
PH-targeted treatments help increase prostacyclin in two ways.
Prostacyclin can be considered a “key” that fits into a “lock” called the prostacyclin IP receptor.
Aside from targeted medication, there are many other therapies that your doctor may recommend to treat your PH. Some may be conventional therapies including supplemental oxygen, diuretics to reduce excess water and salt, and blood thinners to reduce the risk of blood clots. Others may involve surgery. You’ll also want to get PHA’s tips on managing medications and how to deal with side effects.
Supportive medical therapies that may be prescribed for pulmonary hypertension include supplemental oxygen, diuretics and blood thinners among others. Caution is advised for over-the-counter medications.
Surgeries and interventional procedures for pulmonary hypertension include pulmonary thromboendarterectomy, balloon pulmonary angioplasty, atrial septostomy, reverse Potts shunt, and lung or heart-lung transplantation.
Taking charge of your health means getting organized, adhering to your medication regimen and learning what questions to ask your medical team and other patients.
Every drug class that treats pulmonary hypertension has several side effects and drug interactions. Each specific treatment page also lists warnings, but here you can easily compare between types of drugs.
