Cialis tablets contain the active ingredient tadalafil, which is a type of medicine called a phosphodiesterase type 5 inhibitor. It is used to help men with erectile dysfunction to acheive and maintain an erection, and can also be used to relieve the symptoms of an enlarged prostate gland.
Tadalafil works by preventing the action of a chemical in the body called phosphodiesterase type 5.
An erection is produced via a complex chain of events, involving signals from the nervous system and the release of chemical messengers within the tissues of the penis. One of these chemical messengers is called cyclic GMP.
Cyclic GMP causes the blood vessels in the penis to widen by relaxing a thin layer of muscle found in the blood vessel walls. This allows more blood to enter the penis, which ultimately results in the penis becoming rigid and erect. Cyclic GMP is normally broken down by another chemical in the body called phosphodiesterase type 5.
Tadalafil works by preventing the action of phosphodiesterase type 5, thus stopping the breakdown of cyclic GMP. This means that the blood vessels are kept dilated for longer, which improves blood flow to the penis and helps maintain an erection.
As tadalafil only enhances the actions of the chemical messengers responsible for producing an erection, it will only work once these messengers are released in the penis. This means that sexual stimulation is required for it to produce and maintain an erection.
Tadalafil's effect on the blood vessels also improves blood flow to the prostate gland. The prostate gland lies at the top of the tube connecting the bladder to the outside (urethra). The prostate gland often enlarges with advancing age, pressing on the urethra and obstructing the flow of urine from the bladder. This condition, called benign prostatic hyperplasia, can cause various urinary symptoms, such as weak urine flow, difficulty passing urine and frequently needing to pass urine.
By improving the blood flow to the prostate, and also relaxing the muscle in the prostate gland and the bladder, tadalafil helps to relieve these urinary symptoms.
Cialis tablets may be taken with or without food. The tablets should be swallowed whole with a drink of water.
Cialis 10mg and 20mg tablets are intended for use on an 'as needed' basis for erectile dysfunction. With these strength tablets the dose should be taken at least 30 minutes before intended sex. One dose can produce an erection in response to sexual stimulation for up to 36 hours. These tablets should be taken no more than once a day, and should not be taken every day on a continuous basis.
If Cialis 10mg or 20mg tablets work for you, but you anticipate taking Cialis on a regular basis (to have sexual activity at least twice a week), Cialis once-a-day tablets may be an appropriate option for you. These tablets contain a lower dose of tadalafil (2.5mg or 5mg) and are designed to be taken once a day, every day, allowing you to get an erection and have sex whenever you wish. Cialis 2.5mg and 5mg tablets should not be taken more than once a day.
If you are taking Cialis 5mg tablets for an enlarged prostate gland, or erectile dysfunction and an enlarged prostate gland, you should take one tablet once a day, at the same time each day.
Medicines and their possible side effects can affect individual people in different ways. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect. The following are some of the side effects that are known to be associated with Cialis:
Common (affect between 1 in 10 and 1 in 100 people):
- Nasal congestion.
- Indigestion (dyspepsia).
- Heartburn (reflux).
- Back pain.
- Pain in the muscles (myalgia).
Uncommon (affect between 1 in 100 and 1 in 1000 people):
- Blurred vision.
- Eye pain.
- Abdominal pain.
- Increased heart rate (tachycardia).
- Awareness of your heartbeat (palpitations).
- Decrease in blood pressure (hypotension). This is more common in men taking medicines to treat high blood pressure (antihypertensives).
- Increase in blood pressure (hypertension).
- Chest pain.
- Shortness of breath.
The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.
For more information about any other possible risks associated with Cialis, please read the information provided with the medicine or consult your doctor or pharmacist.
Cialis should be used with caution in:
- Decreased kidney function.
- Decreased liver function.
- Disease involving the heart and blood vessels (cardiovascular disease).
- Men taking medicines for high blood pressure (see end of factsheet for more information).
- Conditions such as sickle cell disease, bone marrow cancer (multiple myeloma) or leukaemia, in which there is an increased risk of prolonged erections (priapism).
- Men with a physical abnormality of the penis, such as severe curvature, scarring or Peyronie's disease.
Cialis should NOT be used in:
- Children and adolescents under 18 years of age.
- Conditions in which sexual activity is not advisable, for example severe heart disorders.
- Men with angina not well controlled by medical treatment (unstable angina).
- Men with angina that occurs during sex.
- Men who have had a heart attack in the last three months.
- Men who have had a stroke in the last six months.
- Men with mild to severe heart failure in the last six months.
- Men with abnormal heart beats (arrhythmias) not controlled by treatment.
- Uncontrolled high blood pressure (hypertension).
- Low blood pressure (hypotension).
- Men taking any form of nitrate medications, e.g. glyceryl trinitrate.
- Men who have ever experienced an eye condition called non-arteritic anterior ischemic optic neuropathy (NAION). This condition causes a sudden, partial decrease or loss of vision in one or both eyes due to damage to the optic nerve. It can be temporary or permanent. Talk to your doctor if you have ever experienced this.
- Rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption (Cialis tablets contain lactose).
- Cialis once-a-day dosing is not recommended for men with severely decreased kidney function or kidney failure.
This medicine should not be used if you are allergic to any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
If you feel you have experienced an allergic reaction, stop using Cialis and inform your doctor or pharmacist immediately.
The patient information leaflet (PIL) is a leaflet containing specific information about medical conditions, doses and side effects. You can download a copy of the PIL here:
Patient Info Leaflet