Tadalafil – Uses, Side Effects, and More

Tadalafil is used to treat high blood pressure in the lungs (pulmonary hypertension). It 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.

How to use Tadalafil

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

To treat high blood pressure in the lungs, take this medication by mouth with or without food as directed by your doctor, usually once daily.

If you are using the liquid form of this medication, shake the bottle well for 30 seconds before each dose. Carefully measure the dose using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose.

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.

Tell your doctor if your condition does not improve or if it worsens.

Side Effects

Dizziness, lightheadedness, headache, muscle pain, flushing, nausea, stuffy nose, or stomach upset may occur. If any of these effects last or get 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.

Rarely, sudden decreased vision, including permanent blindness, in one or both eyes (NAION) may occur. If this serious problem occurs, stop taking tadalafil 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 tadalafil and get medical help right away if these effects occur.

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.

Get medical help right away if you have any very serious side effects, including: increased shortness of breath or trouble breathing.

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.

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.

Precautions

Before taking tadalafil, tell your doctor or pharmacist if you are allergic to it; 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: heart problems (such as heart attack or life-threatening irregular heartbeat in the past 6 months, chest pain/angina, heart failure), stroke in the past 6 months, 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), bleeding disorders, active stomach ulcers, other lung conditions (such as pulmonary veno-occlusive disease).

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).

During pregnancy, tadalafil should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this medication passes into breast milk. Consult your doctor before breast-feeding.

Interactions

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, vericiguat.

Tadalafil can cause a serious drop in your blood pressure when used with nitrates, which can lead to dizziness, fainting, and rarely heart attack or stroke. Do not use any of the following with tadalafil or within 48 hours of your last dose of 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 tadalafil from your body, which may affect how tadalafil works. Examples include azole antifungals (such as itraconazole, ketoconazole), macrolide antibiotics (such as clarithromycin, erythromycin), HIV protease inhibitors (such as lopinavir), rifampin, ritonavir, 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).