Many different medications are available to treat pulmonary hypertension (PH). These treatments — all approved by the U.S. Food and Drug and Administration (FDA) — can be effective in reducing symptoms of the condition. They work as vasodilators, meaning they open (or dilate) blood vessels. However, they can also cause side effects, such as gastrointestinal (GI) issues, pain in certain parts of the body, swelling, bleeding, low blood pressure, and others. These side effects vary from person to person and the type of medication.

If you or a loved one are living with PH, speak with your health care provider about the types of medications available and any concerns you may have about potential side effects. If you do start to experience side effects while using a medication, contact your health care provider immediately.

Prostacyclin Analogs

Prostacyclin is a compound naturally produced in the body that makes blood vessels widen to increase blood flow. Prostacyclin analogs are commonly prescribed to treat pulmonary arterial hypertension. Commonly used prostacyclin analogs include epoprostenol (sold as Flolan and Veletri) and treprostinil (sold as Orenitram, Remodulin, and Tyvaso).

Side Effects of Prostacyclin Analogs

Prostacyclin analogs are potent drugs that can cause a number of side effects. Generalized side effects of treatment include nausea, vomiting, and headaches. Other common side effects can include:

• Excessive hair growth
• Flushing
• Pain in joints and chest

Soluble Guanylate Cyclase Stimulators

Soluble guanylate cyclase (sGC) stimulators widen blood vessels by stimulating activity of a protein called guanylate cyclase. The sGC stimulators may be used to treat chronic thromboembolic pulmonary hypertension, a type of PH where blood clots block the arteries in the lungs for long periods of time. A commonly prescribed sGC stimulator is riociguat (Adempas).

Side Effects of Soluble Guanylate Cyclase Stimulators

Treatment with sGC stimulators can cause side effects consistent with symptoms of low blood pressure, including nausea, headache, dizziness, and lightheadedness.

Gastrointestinal issues may also occur as a result of treatment. GI-related side effects include upset stomach and gastroesophageal reflux disease (GERD).

People undergoing treatment may also experience:

• Peripheral edema (swelling of the extremities)
• Stuffy nose
• Nosebleeds

Endothelin Receptor Antagonists

Endothelin receptor antagonists (ERAs) reduce the function of endothelins, molecules that cause constriction of the blood vessels. Drugs that fall into this class include:

• Ambrisentan (Letairis)
• Macitentan (Opsumit)
• Bosentan (Tracleer) ​​

Side Effects of Endothelin Receptor Antagonists

As with many other PH medications, ERAs can result in low blood pressure and can cause side effects such as nausea and dizziness. Other common side effects include:

• Abnormal liver function
• Anemia (low red blood cell count)
• Peripheral edema

GI problems such as constipation, diarrhea, and GERD are also common.

ERAs can lead to serious side effects including pulmonary edema (an accumulation of fluid in the lungs) and reproductive defects. Special consideration for pregnant women should be taken before prescribing ERAs.

Phosphodiesterase Type 5 Inhibitors

Phosphodiesterase type 5 (PDE5) is an enzyme that, similar to endothelins, plays a role in constricting blood vessels. These drugs help to dilate blood vessels and reduce blood pressure. This class of drugs includes tadalafil (Adcirca) and sildenafil (Revatio).

Side Effects of Phosphodiesterase Type 5 Inhibitors

PDE5 inhibitors commonly cause headaches, low blood pressure, and flushing of the skin caused by dilated blood vessels. Other side effects include:

• Headaches
• Facial flushing
• Nasal congestion
• Indigestion

In rare cases, PDE5 inhibitors have been associated with severe side effects including sudden loss of vision or hearing. PDE5 inhibitors are also used to treat erectile dysfunction and can cause prolonged, painful erections that require medical attention.

Anticoagulants

Anticoagulants reduce the coagulation (clumping) of blood cells, thereby thinning the blood and reducing the risk of blood clots. The most common anticoagulant drug used in the treatment of pulmonary hypertension is warfarin (Coumadin). ​​

Side Effects of Anticoagulants

Due to its function as a blood thinner, the primary side effect associated with anticoagulant treatment is excessive bleeding. This can manifest in several ways, including:

• Bleeding gums
• Blood in urine or stool
• Irregular vaginal bleeding or heavy periods
• Pain in the back or chest
• Vomiting blood

In the event of an injury or bodily trauma, a person taking an anticoagulant runs the risk of bleeding becoming uncontrollable. Such a case would require immediate medical attention.

Diuretics

Also called water pills, diuretics are often prescribed to treat high blood pressure. This class of drugs works by eliminating sodium and water through urination, thereby lowering blood pressure. Common diuretics include:

• Furosemide (Lasix)
• Metolazone (sold under brands including Mykrox and Zaroxolyn)
• Spironolactone (sold as Aldactone and Carospir)

Side Effects of Diuretics

Due to their mechanism of action, diuretics generally cause an increase in urination. Additional side effects can include dehydration, headaches, low sodium, and muscle cramps.

Diuretics also can affect potassium levels, causing them to become too high or too low, depending on the exact drug given. On rare occasions, a very low potassium level can result in a life-threatening condition.

Calcium Channel Blockers

Calcium channel blockers dilate the arteries and decrease the force with which the heart pumps. This can relieve high blood pressure and other conditions such as chest pain. Types of calcium channel blockers include:

• Amlodipine (sold as Amvaz, Katerzia, and Norvasc)
• Diltiazem (sold under brands such as Cardizem, Dilacor, and Taztia)
• Nifedipine (sold under brands including Adalat, Nifedical XL, and Procardia)

Side Effects of Calcium Channel Blockers

Common side effects of this treatment include:

• Dizziness
• Constipation
• Headache
• Heart palpitations

Grapefruit juice can exacerbate some of these side effects and should be avoided while taking calcium channel blockers.

Talk With Others Who Understand

MyPHTeam is the social network for people with pulmonary hypertension and their loved ones. On myPHteam, more than 46,000 members come together to ask questions, give advice, and share their stories with others who understand life with PH.

Are you or a loved one living with side effects of pulmonary hypertension medications? Share your experience in the comments below, or start a conversation by posting on your Activities page.