In the U.S.—

• Impotence therapy agent (systemic)

Tadalafil (tah-DAL-a-fil ) is a medicine used to treat erectile dysfunction in men. 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. This results in an erection. Tadalafil helps increase blood flow to the penis and may help men with erectile dysfunction get and keep an erection satisfactory for sexual activity. Once a man has completed sexual activity, blood flow to his penis decreases, and his erection goes away.

CIALIS is available only with your doctor's prescription, in the following dosage forms:

Oral
• Tablets (U.S.)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For tadalafil, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to tadalafil. Also tell your doctor and pharmacist if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Tadalafil is for use in men only. Tadalafil has not been studied in pregnant women. Tadalafil has not been shown to cause birth defects or other problems in animals.

Breast-feeding—Tadalafil is for use in men only. It is not known whether tadalafil passes into human breast milk.

Children—Tadalfil is not for use in children.

Older adults—CIALIS has been tested in a limited number of patients 65 years of age or older and has not been shown to cause different side effects or problems in older people than it does in younger adults.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking tadalafil, it is especially important that your doctor and pharmacist know if you are taking any of the following:

• Erectile dysfunction medicines—these medicines should not be used at the same time as tadalafil because the safety of using these medicines in combination has not been proven.

• Nitrates (medicine used to treat chest pain [e.g., nitroglycerin])—these medicines should not be used at the same time as tadalafil because they can cause very low blood pressure and serious side effects

• Alcoholic beverages— drinking alcohol can cause an increased chance of some side effects.

• Alpha blockers, other than tamsulosin 0.4 mg taken once a day (medicine for high blood pressure)—these medicines should not be used at the same time as tadalafil because they can cause very low blood pressure and serious side effects

• Erythromycin (e.g., Apo-erythro) or
• Itraconazole (e.g., Sporanox) or
• Ketoconazole (e.g., Nizoral) or
• Grapefruit juice or
• Ritonavir (e.g., Norvir) or
• Saquinavir (e.g., Fortovase, Invirase)—These medicines or food may increase your chance of getting side effects.

• Angina (reoccurring chest pain) or
• Arrhythmia (irregular heartbeat) or
• Hypotension (low blood pressure) or
• Hypertension (high blood pressure) or
• Stroke (recent history of) or
• Heart attack (within the last 3 months) or
• Heart failure (within the last 6 months) or
• Retinal disorders (rare hereditary eye problem)
• Stroke (within the last 6 months)—tadalafil has not been studied in patients with these medical conditions and should not be used

• Kidney disease (severe)—tadalafil should be used with caution in these patients and a lower dose may be needed

• Liver disease—tadalafil should not be used in patients with serious liver disease; in patients with less serious liver disease, tadalafil should be used with caution and a lower dose may be needed

• Abnormal penis, including curved penis and birth defects of the penis—chance of problems occurring may be increased and CIALIS should be used with caution in these patients

• Bleeding disorders or
• Stomach ulcers—chance of problems occurring may be increased; it is not known if the medicine is safe for use in these patients

• Heart disease, underlying—chance of low blood pressure occurring is greater; tadalafil should be used carefully in these patients

• Heart blood flow problems—these conditions may cause you to be more sensitive to tadalafil

• Sickle-cell anemia (blood disorder) or
• Bone marrow cancer or
• Leukemia (blood related cancer)—tadalafil should be used with caution in these patients as problems with prolonged erection of the penis may occur

Special patient directions come with tadalafil. Read the directions carefully before you start using tadalafil and each time you get a refill of your medicine.

Use tadalafil exactly as directed by your doctor. Do not use more of it and do not use it more often than your doctor ordered. If too much is used, the chance of side effects or other problems is increased.

Dosing—

The dose of tadalafil will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of tadalafil. If your dose is different, do not change it unless your doctor tells you to do so.

• For oral dosage form (tablets):
  • For treatment of erectile dysfunction:
    • Adults—10 mg as a single dose no more than once a day, taken before you think sexual activity may occur. The ability to have sexual activity may be improved up to 36 hours after taking tadalafil when compared to placebo (sugar pill). If needed, your doctor may change your dose.

Storage—

To store CIALIS:

• Keep out of the reach of children.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Keep the medicine from freezing. Do not refrigerate.
• Do not keep outdated medicine or medicine no longer needed. Ask your health care professional how you should dispose of any medicine you do not use. Be sure that any discarded medicine is out of the reach of children.