Tadalafil is used to treat men who have erectile dysfunction (also called sexual impotence). Tadalafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. These medicines prevent an enzyme called phosphodiesterase type-5 from working too quickly. The penis is one of the areas where this enzyme works.

Erectile dysfunction is a condition where the penis does not harden and expand when a man is sexually excited, or when he cannot keep an erection. When a man is sexually stimulated, his body's normal response is to increase blood flow to his penis to produce an erection. By controlling the enzyme, tadalafil helps to maintain an erection after the penis is stroked by increasing blood flow to the penis. Without physical action to the penis, such as that occurring during sexual intercourse, tadalafil will not work to cause an erection.

Tadalafil is also used to treat men who have signs and symptoms of benign prostatic hyperplasia (BPH). BPH is caused by an enlarged prostate. Men with BPH usually have difficulty urinating, a decreased flow of urination, hesitation at the beginning of urination, and a need to get up at night to urinate. Tadalafil will make these symptoms less severe and reduce the chance that prostate surgery will be needed. This medicine is also used to treat erectile dysfunction and signs and symptoms of BPH.

Tadalafil is also used in both men and women to treat the symptoms of pulmonary arterial hypertension to improve your ability to exercise. This is high blood pressure that occurs in the main artery that carries blood from the right side of the heart (the ventricle) to the lungs. When the smaller blood vessels in the lungs become more resistant to blood flow, the right ventricle must work harder to pump enough blood through the lungs. Tadalafil works on the PDE5 enzyme in the lungs to relax the blood vessels. This will increase the supply of blood to the lungs and reduce the workload of the heart.

This medicine is available only with your doctor's prescription. .

Use tadalafil exactly as directed by your doctor. Do not use more of it, do not use it more often, and do not use it for a longer time than your doctor ordered. Also, do not stop taking this medicine without checking first with your doctor.

This medicine comes with a patient information leaflet. Read and follow these instructions carefully. Read it again each time you refill your prescription in case there is new information. Ask your doctor if you have any questions.

You may take this medicine with or without food.

Swallow the tablet whole. Do not split, break, chew, or crush it.

When using this medicine for erectile dysfunction, the ability to have sexual activity may be improved for up to 36 hours after taking the tablet.

Use only the brand of this medicine that your doctor prescribed. Different brands may not work the same way.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Less common

Arm, back, or jaw pain

blurred vision

chest pain or discomfort

chest tightness or heaviness

chills

cold sweats

confusion

dizziness

fainting

faintness or lightheadedness when getting up suddenly from a lying or sitting position

fast or irregular heartbeat

headache

hearing loss

increased erection

nausea

nervousness

pain or discomfort in the arms, jaw, back, or neck

pounding in the ears

slow or fast heartbeat

spontaneous penile erection

sweating

unusual tiredness or weakness

vomiting

Rare

Painful or prolonged erection of the penis

Incidence not known

Blindness

blistering, peeling, or loosening of the skin

cough

cracks in the skin

decrease or change in vision

diarrhea

difficulty with speaking

double vision

fast, irregular, pounding, or racing heartbeat or pulse

headache, severe and throbbing

hives or welts, itching, skin rash

inability to move the arms, legs, or facial muscles

inability to speak

joint or muscle pain

loss of heat from the body

numbness or tingling of the face, hands, or feet

red skin lesions, often with a purple center

red, irritated eyes

red, swollen skin

redness of the skin

redness or soreness of the eyes

scaly skin

slow speech

sores, ulcers, or white spots in the mouth or on the lips

stomach pain

sudden cardiac death

swelling of the feet or lower legs

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Belching

heartburn

indigestion

stomach discomfort, upset, or pain

Less common

Bloody nose

body aches or pain

burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings

burning, dry, or itching eyes

burning feeling in the chest or stomach

congestion

difficulty with moving

difficulty with swallowing

dry mouth

dryness or soreness of the throat

excessive eye discharge

eye pain

feeling of constant movement of self or surroundings

feeling of warmth, redness of the face, neck, arms and occasionally, upper chest

fever

hoarseness

lack or loss of strength

loose stools

muscle aching or cramping

muscle stiffness

nasal congestion

neck pain

pain

pain in the arms or legs

pain or burning in the throat

redness, pain, swelling of the eye, eyelid, or inner lining of the eyelid

reduced sensitivity to touch

runny nose

sensation of spinning

sleepiness or unusual drowsiness

stomach upset

swelling of the eyelids

swelling or puffiness of the eyes or face

swollen joints

tearing

tender, swollen glands in the neck

tenderness in the stomach area

trouble with sleeping

upper abdominal or stomach pain

voice changes

watering of the eyes

Rare

Changes in color vision

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

It is important that you tell all of your doctors that you take tadalafil. If you need emergency medical care for a heart problem, it is important that your doctor knows when you last took tadalafil.

If you will be taking this medicine for pulmonary arterial hypertension, it is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it. Blood and urine tests may be needed to check for unwanted effects.

If you take tadalafil for pulmonary arterial hypertension, do not take Cialis® or other PDE5 inhibitors, such as sildenafil (Revatio® or Viagra®) or vardenafil (Levitra®). Cialis® also contains tadalafil. If you take too much tadalafil or take it together with these medicines, the chance for side effects will be higher.

If you experience a prolonged erection for more than 4 hours or a painful erection for more than 6 hours, contact your doctor immediately. This condition may require prompt medical treatment to prevent serious and permanent damage to your penis.

This medicine does not protect you against sexually transmitted diseases (including HIV or AIDS). Use protective measures and ask your doctor if you have any questions about this.

It is important to tell your doctor about any heart problems you have now or may have had in the past. This medicine can cause serious side effects in patients with heart problems.

Do not use this medicine if you are also using riociguat or a nitrate medicine, often used to treat angina (chest pain). Nitrate medicines include nitroglycerin, isosorbide, Imdur®, Nitro-Bid®, Nitrostat®, Nitro-Dur®, Transderm Nitro®, Nitrol® Ointment, and Nitrolingual® Spray. Some illegal ("street") drugs called "poppers" (such as amyl nitrate, butyl nitrate, or nitrite) also contain nitrates. If you need to use a nitrate medicine, take it at least 48 hours after your last dose of tadalafil.

Do not drink excessive amounts of alcohol (eg, 5 glasses of wine or 5 shots of whiskey) when taking tadalafil. When taken in excess, alcohol can increase your chances of getting a headache or dizziness, increase your heart rate, or lower your blood pressure.

If you experience sudden loss of vision in one or both eyes, contact your doctor immediately.

Check with your doctor right away if you have a sudden decrease in hearing or loss of hearing, which may be accompanied by dizziness and ringing in the ears.

Do not eat grapefruit or drink grapefruit juice while you are using this medicine. Grapefruit and grapefruit juice may change the amount of this medicine that is absorbed in the body.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.