This combination medication contains 2 drugs: macitentan and tadalafil. It is used by people who are currently taking stable doses of these 2 drugs to treat high blood pressure in the lungs (pulmonary hypertension). Macitentan blocks the effects of a certain natural substance (endothelin-1). Blocking this substance helps decrease blood pressure in the lungs. Tadalafil works by relaxing and widening the blood vessels in your lungs which allows the blood to flow more easily. Decreasing high blood pressure in the lungs allows your heart and lungs to work better and improves your ability to exercise.

Read the Medication Guide and, if available, the Patient Information Leaflet provided by your pharmacist before you start taking macitentan/tadalafil and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth with or without food as directed by your doctor, usually once daily. Swallow the tablets whole. Do not break, crush, or chew the tablets. The dosage is based on your medical condition, response to treatment, and other medications you may be taking. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Take this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.

Since this drug can be absorbed through the skin and lungs and may harm an unborn baby, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets.

Tell your doctor if your condition does not get better or if it gets worse.

Runny/stuffy nose, sore throat, cough, chills, dizziness, lightheadedness, headache, muscle pain, flushing, nausea, vomiting, or stomach upset may occur. If any of these effects last or gets worse, tell your doctor or pharmacist promptly.

To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• signs of low red blood cell count (such as unusual tiredness, rapid breathing, pale skin, shortness of breath, fast heartbeat)
• unusual weight gain
• increased shortness of breath or trouble breathing
• new or worsening swelling of the hands/ankles/feet
• signs of liver disease (such as nausea/vomiting that doesn't stop, dark urine, stomach/abdominal pain, yellowing eyes/skin)

Rarely, sudden decreased vision, or even permanent blindness, may occur in one or both eyes (NAION). If this serious problem occurs, stop taking this medication and get medical help right away. You have a slightly greater chance of developing NAION if you have heart disease, diabetes, high cholesterol, certain other eye problems ("crowded disk"), high blood pressure, if you are over 50, or if you smoke.

Rarely, a sudden decrease or loss of hearing, sometimes with ringing in the ears and dizziness, may occur. Stop taking this medication and get medical help right away if you get any of these side effects.

Rarely, males may have a painful or prolonged erection lasting 4 or more hours. If this occurs, stop using this drug and get medical help right away, or permanent problems could occur.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking this medication, tell your doctor or pharmacist if you are allergic to macitentan or tadalafil; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• bleeding/blood disorders (such as anemia)
• other lung conditions (such as pulmonary veno-occlusive disease)
• heart problems (such as angina, previous heart attack, irregular heartbeat, heart failure)
• kidney disease
• liver disease
• high or low blood pressure
• dehydration
• penis conditions (such as angulation, fibrosis/scarring, Peyronie's disease)
• history of painful/prolonged erection (priapism)
• conditions that may increase the risk of priapism (such as sickle cell anemia, leukemia, multiple myeloma)
• eye problems (such as retinitis pigmentosa, sudden decreased vision, NAION)
• stroke

This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

This medication can affect fertility in males. Ask your doctor for more details.

Since this drug can be absorbed through the skin and lungs and may harm an unborn baby, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets.

This medication must not be used during pregnancy. It may harm an unborn baby. Discuss the use of reliable forms of birth control (such as condoms, birth control pills) during treatment and for 1 month after the last dose. If you become pregnant or think you may be pregnant, tell your doctor right away. See also Warning section.

It is unknown if this medication passes into breast milk. Because of the possible risk to the infant, breastfeeding is not recommended while using this medication. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug are:

• riociguat
• sparsentan
• vericiguat

When used with nitrates, this medication can cause a serious drop in your blood pressure, which can lead to dizziness, fainting, and rarely heart attack or stroke. Do not use any of the following drugs during treatment with this medication or within 48 hours of your last dose of macitentan/tadalafil:

• certain drugs used to treat chest pain/angina (nitrates such as nitroglycerin, isosorbide)
• recreational drugs called "poppers" containing amyl or butyl nitrite

If you are also taking an alpha blocker medication (such as doxazosin, tamsulosin) to treat an enlarged prostate/BPH or high blood pressure, your blood pressure may get too low which can lead to dizziness or fainting. Your doctor may adjust your medications to minimize your risk of low blood pressure.

Other medications can affect the removal of macitentan/tadalafil from your body, which may affect how this medication works. Examples include amiodarone, azole antifungals (such as itraconazole, ketoconazole), macrolide antibiotics (such as clarithromycin, erythromycin), cobicistat, HIV protease inhibitors (such as lopinavir, ritonavir), rifamycins (such as rifampin), among others.

Do not take this medication with any other product that contains tadalafil or other similar medications for erectile dysfunction-ED or pulmonary hypertension (such as sildenafil, vardenafil).

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Lab and/or medical tests (such as blood pressure, complete blood count, kidney/liver tests) may be done while you are taking this medication. Keep all medical and lab appointments.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store in the original container at room temperature away from light and moisture. Do not store in the bathroom. Keep the drying agent (desiccant) in the bottle. Tightly close the bottle when not in use. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.