Macitentan and tadalafil may cause life-threatening birth defects or death of the unborn baby. Before taking macitentan, tell your doctor if you are pregnant, or plan to become pregnant. Macitentan and tadalafil should not be used during pregnancy.
You will have to take a pregnancy test before starting treatment. You must use reliable birth control throughout your treatment with macitentan and tadalafil, and for 1 month after your final dose. Your doctor will tell you which forms of birth control are acceptable, and will give you written information about birth control. In most cases you will be required to use two forms of birth control in order to prevent pregnancy while taking macitentan and tadalafil.
Call your doctor right away if you have had unprotected sex, think your birth control failed, missed your period, or think you may be pregnant. He will discuss your medical options with you. Do not wait until your next appointment to discuss this with your doctor.
Your doctor or pharmacist will give you the Medication Guide when you begin treatment with macitentan and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit https://www.fda.gov/Drugs/DrugSafety/ucm085729.htm or the manufacturer's website to obtain the Medication Guide.
Why is this medicine prescribed?
Macitentan and tadalafil is used to treat certain types of pulmonary arterial hypertension (PAH; high blood pressure in the blood vessels that carry blood to the lungs. Macitentan is in a class of medications called endothelin receptor antagonists. It works by stopping the action of endothelin, a natural substance that causes blood vessels to narrow. Tadalafil is in a class of medications called phosphodiesterase (PDE) inhibitors. It works by relaxing the blood vessels in the lungs to allow blood to flow more easily.
Are there other uses for this medicine?
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
How should this medicine be used?
Macitentan and tadalafil comes as a tablet to take by mouth. Take with or without food once a day. Take macitentan and tadalafil at around the same time every day.
Take macitentan and tadalafil exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Swallow the tablets whole; do not split, chew, or crush them.
Your doctor may start you on a low dose of macitentan and tadalafil and increase your dose after a week.
What special precautions should I follow?
Before taking macitentan and tadalafil,
- tell your doctor or pharmacist if you are allergic to this drug, any part of this drug, or any other drugs, foods or substances. Tell your doctor or pharmacist about the allergy and what symptoms you had.
- some medications should not be taken with macitentan and tadalafil. Other medications may cause dosing changes or extra monitoring when taken with macitentan and tadalafil. Make sure you have discussed any medications you are currently taking or plan to take before starting macitentan and tadalafil with your doctor and pharmacist. Before starting, stopping, or changing any medications while taking macitentan and tadalafil, please get the advice of your doctor or pharmacist.
- you should know that the following nonprescription or herbal product may interact with macitentan: St. John's wort. Be sure to let your doctor and pharmacist know that you are taking St. John's wort before you start taking macitentan. Do not start St.John's wort while taking macitentan without discussing with your healthcare provider.
- tell your doctor if you have or have ever had liver disease, low blood pressure, heart disease or heart failure, anemia (low red blood cell count), pulmonary veno-occlusive disease (PVOD; blockage of veins in the lungs), angina (chest pain), stroke, any condition that affects the shape of the penis; blood circulation problems; blood cell problems such as sickle cell anemia (a disease of the red blood cells), multiple myeloma (cancer of the plasma cells), or leukemia (cancer of the white blood cells); or kidney disease.
- you should not breastfeed while receiving macitentan and tadalafil.
- you should know that macitentan and tadalafil may cause dizziness, lightheadedness, and fainting when you get up too quickly from a lying position. To avoid this problem, get out of bed slowly, resting your feet on the floor for a few minutes before standing up.
- you should know that macitentan and tadalafil may decrease fertility in men. Talk to your doctor about the risks of taking macitentan.
- ask your doctor about the safe use of alcoholic beverages while you are taking macitentan and tadalafil. Alcohol can make the side effects from macitentan and tadalafil, such as dizziness, headache and changes in blood pressure, worse.
What special dietary instructions should I follow?
Unless your doctor tells you otherwise, continue your normal diet.
What should I do if I forget to take a dose?
Take the missed dose as soon as you remember it on that day. Then take the next dose at the regular time and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
What should I do in case of overdose?
In case of overdose, call the poison control helpline at 1-800-222-1222
. Information is also available online at https://www.poisonhelp.org/help . If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.
What side effects can this medicine cause?
Macitentan and tadalafil may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- swelling in face, arms or legs
- headache
- abdominal pain
Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:
- nausea or vomiting, stomach or belly pain, tiredness, loss of appetite, yellowing of skin or whites of eye, dark urine, itching
- low blood pressure which may cause symptoms such as dizziness or lightheadedness
- tiredness, pale skin color, cold hands or feet, difficulty concentrating
- unusual weight gain, trouble breathing or swelling of ankles or legs
- erection that lasts longer than 4 hours with or without pain
Some patients experienced a sudden loss of some or all of their vision after they took tadalafil. The vision loss was permanent in some cases. It is not known if the vision loss was caused by the medication. If you experience a sudden loss of vision while you are taking tadalafil, call your doctor immediately or get emergency medical treatment.
Some patients experienced a sudden decrease or loss of hearing after they took tadalafil. The hearing loss usually involved only one ear and did not always improve when the medication was stopped. It is not known if the hearing loss was caused by the medication. If you experience a sudden loss of hearing, sometimes with ringing in the ears or dizziness, while you are taking tadalafil, call your doctor immediately.
Macitentan and tadalafil may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online ( https://www.fda.gov/Safety/MedWatch ) or by phone (
1-800-332-1088).What should I know about storage and disposal of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).
Keep all medication out of sight and reach of children as many containers are not child resistant. Always lock safety caps. Place the medication in a safe location – one that is up and away and out of their sight and reach. https://www.upandaway.org
Dispose of unneeded medications in a way so that pets, children, and other people cannot take them. Do not flush this medication down the toilet. Use a medicine take-back program. Talk to your pharmacist about take-back programs in your community. Visit the FDA's Safe Disposal of Medicines website ( https://goo.gl/c4Rm4p ) for more information.
What other information should I know?
Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your body's response to macitentan and tadalafil.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.