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Drugs reference index «Cialis»



Generic name: TadalafilBrand names: Cialis

Why is Cialis prescribed?

Cialis is an oral drug for male impotence, also known as erectile dysfunction (ED). It works by dilating blood vessels in the penis, allowing the inflow of blood needed for an erection.

Most important fact about Cialis

Cialis causes erections only during sexual excitement. It does not work in the absence of arousal and does not increase sexual desire.

How should you take Cialis?

Take one Cialis tablet before sexual activity, with or without food. The best time to take Cialis depends on how and when the drug works for you, but some men are able to have an erection 30 minutes after taking it. Others are able to wait up to 36 hours after taking Cialis before engaging in sexual activity.

  • If you miss a dose...Take Cialis only before sexual activity, but no more than once a day. Do not take two doses at once.
  • Storage instructions...Store at room temperature.

What side effects may occur?

Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe to continue using Cialis.

  • Side effects may include:Arm and leg pain, back pain, flushing, headache, indigestion, muscle aches, nasal congestion

Why should Cialis not be prescribed?

Do not take Cialis if you are taking any nitrate-based drug, including nitroglycerin patches, nitroglycerin ointment, nitroglycerin pills, and isosorbide pills. This also includes street drugs known as "poppers," including amyl nitrate and butyl nitrate. Combining Cialis with any of these drugs can cause a dangerous drop in blood pressure.

Likewise, do not take Cialis with certain blood pressure and prostate drugs known as alpha-blockers, including doxazosin, terazosin, prazosin, and alfuzosin. However, you can take the alpha-blocker tamsulosin at a dose of 0.4 milligrams once a day.

If Cialis gives you an allergic reaction, do not use it again.

Special warnings about Cialis

If you have heart problems severe enough to make sexual activity a danger, you should avoid using Cialis. If you take Cialis and develop cardiac symptoms (for example, dizziness, nausea, and chest pain) during sexual activity, do not continue. Alert your doctor to the problem as soon as possible.

Because Cialis has not been studied in people with cardiovascular disease, it's best to avoid Cialis if you've had a stroke or heart failure within the past 6 months, or a heart attack within the past 3 months. Be equally cautious if you have severe high or low blood pressure, heartbeat irregularities, or unstable angina (crushing heart pain that occurs at any time). If you develop angina after taking Cialis, seek medical attention immediately.

If you have severe kidney or liver problems, a bleeding disorder, stomach ulcer, or an inherited retinal disorder such as retinitis pigmentosa, use Cialis with caution. Its safety under these circumstances has not yet been studied.

Rare cases of prolonged and sometimes painful erections (known as priapism) have been reported with drugs similar to Cialis. If you develop an erection that lasts more than 4 hours, seek medical treatment immediately. Otherwise, permanent damage and impotence could result.

If you have a condition that might result in long-lasting erections, such as sickle cell anemia, multiple myeloma (a disease of the bone marrow), or leukemia, use Cialis with caution. Also use caution if you have a genital problem or deformity such as Peyronie's disease.

Remember that Cialis offers no protection from transmission of sexually transmitted diseases, such as HIV, the virus that causes AIDS.

Possible food and drug interactions when taking Cialis

Be sure to check with your doctor about the medications that should never be taken with Cialis, including:

Alpha-blocking drugs prescribed for high blood pressure or prostate problems, including doxazosin, terazosin, prazosin, and alfuzosinNitrate-based drugs prescribed for chest pain, such as nitroglycerin patches, nitroglycerin ointment, nitroglycerin pills, and isosorbide pillsStreet drugs known as "poppers," including amyl nitrate and butyl nitrate

Cialis could intensify the effects of certain drugs used to lower blood pressure. Be sure to tell your doctor if you take any of the following:

Angiotensin II receptor blockers, such as candesartan, eprosartan and irbesartanBendrofluazideEnalaprilMetoprol

If Cialis is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Cialis with the following:

Other impotence drugs including alprostadil, sildenafil, and vardenafilErythromycinGrapefruit juiceIndinavirItraconazoleKetoconazoleRifampinRitonavir

It's best not to drink too much alcohol while you're taking Cialis. Combining the two could lower your blood pressure and cause dizziness, especially upon standing. Drinking five or more servings of alcohol could intensify this effect and also cause headache and rapid heartbeat.

Special information if you are pregnant or breastfeeding

Cialis should not be used by women. Its effects during pregnancy and breastfeeding have not been studied.

Recommended dosage for Cialis


Doses range from 5 milligrams to 20 milligrams, depending on the drug's effect. The recommended starting dose is 10 milligrams.

Take Cialis only before sexual activity. The manufacturer recommends a maximum of one dose per day. If you're taking certain drugs that affect the liver, such as ritonavir or ketoconazole, the maximum recommended dose is 10 milligrams no more than once every 3 days.

If you have moderate kidney impairment, the recommended starting dose is 5 milligrams once a day, up to a maximum of 10 milligrams once every 2 days. If you have severe kidney impairment or need dialysis, the maximum recommended dose is 5 milligrams once a day. No dosage adjustment is required if you have mild kidney problems.

If you have mild or moderate liver impairment, your total daily dose should not exceed 10 milligrams once a day. If your liver is severely impaired, you will not be able to use Cialis.


Large doses of Cialis (up to 500 milligrams) resulted in similar side effects as regular doses. However, any medication taken in excess can have serious consequences. If you suspect an overdose, seek medical attention immediately.

  • Cialis Prescribing Information (FDA)
  • Cialis Advanced Consumer (Micromedex) - Includes Dosage Information
  • Cialis MedFacts Consumer Leaflet (Wolters Kluwer)
  • Cialis Consumer Overview
  • Tadalafil Professional Patient Advice (Wolters Kluwer)
  • Adcirca MedFacts Consumer Leaflet (Wolters Kluwer)
  • Adcirca Prescribing Information (FDA)
  • Adcirca Consumer Overview

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