Who should not take CIALIS? 

One who takes any medicines called nitrates. Nitrates are commonly used to treat angina. Angina is a symptom of heart disease and can cause pain in your chest, jaw, or down your arm. Medicines called nitrates include nitroglycerin that is found in tablets, sprays, ointments, pastes, or patches. Nitrates can also be found in other medicines such as isosorbidedinitrate or isosorbide mononitrate. Some recreational drugs called "poppers" also contain nitrates, such as amyl nitrite and butyl nitrite. Do not use CIALIS if you are using these drugs. Ask your doctor or pharmacist if you are not sure if any of your medicines are nitrates.
you have been told by your healthcare provider to not have sexual activity because of health problems. Sexual activity can put an extra strain on your heart, especially if your heart is already weak from a heart attack or heart disease.
are allergic to CIALIS or any of its ingredients. The active ingredient in CIALIS is called tadalafil. See the end of this leaflet for a complete list of ingredients.

What should you discuss with your doctor before taking CIALIS?

Tell your doctor about all your medical problems, including if you:
Have heart problems such as angina

Heart failure

Irregular heartbeats, or have had a heart attack

Ask your doctor if it is safe for you to have sexual activity.
Have low blood pressure or have high blood pressure that is not controlled
Have had a stroke
Have liver problems
Have kidney problems or require dialysis
Have retinitis pigmentosa, a rare genetic (runs in families) eye disease
Have stomach ulcers
Have a bleeding problem
Have a deformed penis shape or Peyronie's disease
Have had an erection that lasted more than 4 hours
Have blood cell problems such as sickle cell anemia, multiple myeloma, or leukemia.

How should you take CIALIS?
Take CIALIS exactly as your doctor prescribes. CIALIS comes in different doses (5 mg, 10 mg, and 20 mg). For most men, the recommended starting dose is 10 mg. CIALIS should be taken no more than once a day. Some men can only take a low dose of CIALIS because of medical conditions or medicines they take. Your doctor will prescribe the dose that is right for you.

What are the possible side effects from Cialis?
The most common side effects with CIALIS are headache, indigestion, back pain, muscle aches, flushing, and stuffy or runny nose. These side effects usually go away after a few hours. Patients who get back pain and muscle aches usually get it 12 to 24 hours after taking CIALIS. Back pain and muscle aches usually go away by themselves within 48 hours. Call your doctor if you get a side effect that bothers you or one that will not go away.

How well do these drugs work?

Very well. These drugs increase the satisfaction with the hardness of erections and maintain the erection throughout intercourse. Once intercourse is over, the erection goes away. Keep in mind that the cause of your ED does play a role in how effective these medications are. For instance, chronic health conditions such as poorly controlled diabetes may interfere with how well these medications work.

What are the differences between the three medications?

Not a whole lot. All three work on the same actions in the body in order to create an erection only when the man is sexually stimulated. Viagra, Levitra and Cialis are in a class of medications called PDE5 inhibitors. When a man becomes sexually stimulated, his brain sends out nerve signals, which cause a release of a chemical called nitric oxide. This chemical relaxes muscles in the penis to allow more blood to flow in, causing a hard, erect penis. These drugs help enhance the effects of the nitric acid.

The three drugs only work when you are sexually stimulated. The differences are largely in their timing. Viagra can work in as little as 14 minutes, but usually works within 30 minutes. Viagra works for at least four hours. Levitra may be effective for as long as five to six hours and start working within 15 to 25 minutes. Cialis can be effective for as long as 36 hours and starts working within 30 minutes.

Do I have to take these with food?

No. These medications are just as effective without or with food. Absorption is not affected.

Can you be too old or too young to take these?

No. Age is not a factor in whether or not men can take this or if the medications will work. ED, by the way, can strike men at any age.