Fast facts on Cialis:

Here are some key points about Cialis. More detail is in the main article.

  • Under the name Cialis, tadalafil is used to treat erectile dysfunction.
  • As Adcirca, the same drug treats pulmonary arterial hypertension and benign prostatic hyperplasia.
  • Cialis increases blood flow to the penis, enabling an erection to occur when a man is sexually stimulated.
  • Anyone with a heart condition should seek medical advice before using Cialis.
  • Cialis is a medication, with potentially serious adverse effects. It should only be obtained from a reputable source and used under medical supervision.

Cialis is the brand name for tadalafil, a drug used to treat erectile dysfunction. It is similar to Viagra and Levitra. Under the brand name Adcirca, tadalafil is used for pulmonary arterial hypertension.

Cialis increases blood flow to the penis, and this enables a man to achieve an erection. It does not lead to sexual arousal. It should be used with caution, and only under medical supervision.

Tadalafil was approved by the United States (U.S.) Food and Drug Administration (FDA) in 2003 for the treatment of erectile dysfunction (ED). It is also used to treat pulmonary arterial hypertension and benign prostatic hyperplasia, a condition in which the prostate gland becomes enlarged, causing problems with urination.

Cialis used as a medication for erectile dysfunction.Share on Pinterest
Cialis used as a medication for erectile dysfunction.

Penile erection occurs when the penis fills with blood. This happens because the blood vessels that bring blood flow to the penis dilate, increasing the blood supply. At the same time, the blood vessels that remove blood from the penis contract. The blood accumulates in the penis, causing an erection.

When a man is sexually stimulated, nitric oxide is released into the penis. Nitric oxide enables the production of cGMP, which controls the dilation and contraction of the blood vessels that carry blood to and from the penis.

Another substance, PDE5, destroys cGMP. When this occurs, the blood vessels return to their normal size, and the erection ends. Tadalafil stops PDE5 from destroying cGMP. This causes the erection to last for longer.

The muscles of the arteries in the walls of the lungs also contain PDE5, which is why the same drug can also help with pulmonary hypertension treatment.

Cialis comes in yellow, film-coated and almond-shaped tablets in 5, 10 and 20 milligram (mg) doses.

Patients with erectile dysfunction can take Cialis as needed, but it should not be taken more frequently than once every 24 hours.

For the medication to work, a man needs to be sexually aroused. The drug does not provide an erection without sexual stimulation.

A first dose is 10 milligrams (mg) at least 30 minutes before sexual activity. Dosage can then be adjusted depending on how the individual responds. The maximum is 20 mg as a single dose.

The patient should take no more than one dose in 24 hours, but a daily dose of 10 mg to 20 mg is not recommended. This is because a portion of the drug remains in the system for at least 24 hours.

Patients who expect to be sexually active at least twice a week can take a daily dose of 5 mg, and this may be reduced to 2.5 mg once daily, depending on the individual reaction.

Tadalafil for erectile dysfunction is only for use by adults aged 18 years and above.

Taking tadalafil, or Cialis, with a nitrate medication can cause a serious and sudden drop in blood pressure, or hypotension.

A man who is taking a nitrate drug prescription for heart problems or chest pain should not use tadalafil.

The producers of the drug, Eli Lilly, warn that if the following symptoms occur during sexual activity, they could be a sign of a serious complication. Immediate medical assistance should be sought:

  • dizziness
  • nausea
  • numbness, tingling or pain the jaw, arms, chest, or neck

If an erection lasts for more than 4 hours, this is known as priapism. It can damage the penis, so medical assistance is necessary.

In rare cases, Cialis can undermine the blood flow to the optic nerve of the eye, causing sudden loss of vision. This is more likely in patients with hypertension, diabetes, high cholesterol, pre-existing eye problems, or heart disease.

People with the following conditions should not take Cialis unless a physician agrees:

  • heart rhythm problems, angina, or any kind of heart disease
  • high or low blood pressure
  • congestive heart failure or stroke within the last 6 months, or myocardial infarction within the last 3 months
  • sickle cell anemia, multiple myeloma, hemophilia, leukemia, or another blood disorder
  • liver or kidney disease
  • stomach ulcer
  • retinitis pigmentosa
  • structural deformity of the penis, such as Peyronie's disease
  • any health condition for which they have been advised not to have sexual intercourse

The FDA has warned about sudden hearing loss experienced by people using tadalafil and similar products.

In 2016, the FDA announced that they were "evaluating the need for regulatory action" following indications that using Cialis and similar drugs might increase the risk of melanoma skin cancer.

However, some researchers have questioned how serious the risk is.

Where can I get Cialis?

Cialis is available by prescription and should be used under the supervision of a medical professional.

It can be purchased online, but this is not advisable.

The FDA issued a warning in 2015 about counterfeit tadalafil tablets that had become available in the U.S. It is important always to obtain medications from a reputable source, because using fake drugs can be dangerous.