Tadalafil is a prescription-only active ingredient approved by the FDA for erectile dysfunction. It was popularized by the brand name Cialis and is designed to last longer than Sildenafil.

Cialis (tadalafil) relaxes muscles of the blood vessels and increases blood flow to particular areas of the body.

Cialis is used to treat erectile dysfunction (impotence) and symptoms of benign prostatic hypertrophy (enlarged prostate).

Another brand of tadalafil is Adcirca, which is used to treat pulmonary arterial hypertension and improve exercise capacity in men and women. Do not take Cialis while also taking Adcirca, unless your doctor tells you to.

Important information

Do not take Cialis if you are also using a nitrate drug for chest pain or heart problems, including nitroglycerin, isosorbide dinitrate, isosorbide mononitrate, and some recreational drugs such as “poppers”. Taking tadalafil with a nitrate medicine can cause a sudden and serious decrease in blood pressure.

Some medicines can cause unwanted or dangerous effects when used with Cialis. Tell your doctor about all your current medicines, especially riociguat (Adempas).

Contact your doctor or seek emergency medical attention if your erection is painful or lasts longer than 4 hours. A prolonged erection (priapism) can damage the penis.

Get medical help at once if you have nausea, chest pain, or dizziness during sex.

Stop using Cialis and get emergency medical help if you have sudden vision loss.

Before taking this medicine

You should not take Cialis if you are allergic to tadalafil.

Taking Cialis with certain other medicines can cause a sudden and serious decrease in blood pressure. Do not take this medicine if you also use:

• riociguat (to treat pulmonary arterial hypertension); or
• a nitrate drug (for chest pain or heart problems) such as nitroglycerin, isosorbide dinitrate, isosorbide mononitrate, or recreational drugs such as amyl nitrate or nitrite “poppers”.

Some tadalafil can remain in your bloodstream for 2 or more days after each dose you take (longer if you have liver or kidney disease). Avoid nitrate use during this time.

To make sure this Cialis is safe for you, tell your doctor if you have ever had:

• heart disease or heart rhythm problems;
• a heart attack or stroke;
• angina (chest pain), high or low blood pressure;
• pulmonary hypertension (unless you are taking tadalafil for this);
• a condition called pulmonary veno-occlusive disease (narrowing of the veins that carry blood from the lungs to the heart);
• liver or kidney disease (or if you are on dialysis);
• vision loss, or retinitis pigmentosa (an inherited condition of the eye);
• a bleeding disorder;
• a blood cell disorder such as sickle cell anemia, multiple myeloma, or leukemia;
• a physical deformity of the penis (such as Peyronie’s disease), or an erection lasting longer than 4 hours;
• a stomach ulcer; or
• health problems that make sexual activity unsafe.

Sudden vision loss has occurred in a small number of people taking medicines like tadalafil (Viagra or others). Most of these people already had certain eye problems or had high cholesterol, diabetes, coronary artery disease, a history of smoking, or were over 50 years old). It is not clear whether the medicine was the actual cause of vision loss.

Cialis is not expected to harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It is not known whether tadalafil passes into breast milk or if it could affect the nursing baby. Tell your doctor if you are breast-feeding.

Cialis is not approved for use by anyone younger than 18 years old.

How should I take Cialis?

Cialis is usually taken only once per day. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Cialis can be taken with or without food.

Do not break or split a tablet. Swallow it whole.

For erectile dysfunction, take Cialis just before sexual activity but not more than once per day.

Cialis can help achieve an erection when sexual stimulation occurs. An erection will not occur just by taking a pill. Follow your doctor’s instructions.

 

Do not take Cialis for erectile dysfunction if you are taking Adcirca for pulmonary arterial hypertension.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

As Cialis is used as needed, you are not likely to be on a dosing schedule.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking Cialis?

Drinking alcohol with this medicine can cause side effects.

Grapefruit and grapefruit juice may interact with tadalafil and lead to unwanted side effects. Avoid the use of grapefruit products while taking this medicine.

Cialis side effects

Get emergency medical help if you have signs of an allergic reaction to Cialis: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop and get medical help at once if you have nausea, chest pain, or dizziness during sex. You could be having a life-threatening side effect.

Stop using this medicine and call your doctor at once if you have:

• a light-headed feeling, like you might pass out;
• an erection is painful or lasts longer than 4 hours (prolonged erection can damage the penis);
• vision changes or sudden vision loss;
• ringing in your ears or sudden hearing loss; or
• heart attack symptoms – chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating.

Common Cialis side effects may include:

• headache;
• flushing (warmth, redness, or tingly feeling);
• nausea, upset stomach;
• stuffy nose; or
• muscle pain, back pain, pain in your arms or legs.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Cialis?

Tell your doctor about all your current medicines and any you start or stop using, especially:

• medicines to treat erectile dysfunction or pulmonary arterial hypertension;
• an antibiotic or antifungal medicine;
• antiviral medicine to treat hepatitis C or HIV/AIDS;
• drugs to treat high blood pressure or a prostate disorder; or
• seizure medicine.

This list is not complete. Other drugs may interact with tadalafil, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Cialis vs Viagra – What’s the difference between them?

Cialis and Viagra are both PDE5 inhibitors used for the treatment of erectile dysfunction (ED). Both only work when a man is sexually aroused. Cialis lasts for around 36 hours compared with only 4 to 5 hours for Viagra. Food does not affect the activity of Cialis, whereas food may decrease the effectiveness of Viagra. Cialis can be used once daily, at a smaller dosage, and is also effective at treating benign prostatic hyperplasia (BPH). Dosage of Cialis may need to be reduced in men with liver or kidney problems and risk of interactions may be higher than with Viagra.

What ingredients are contained in Cialis or Viagra and how do they work?

Cialis is the brand name for tadalafil and Viagra is the brand name for sildenafil. Both belong to a class of medicines known as phosphodiesterase type 5 (PDE5) inhibitors. PDE5 inhibitors work only in the presence of sexual stimulation, as they rely on the natural release of nitric oxide (NO), a chemical only released during sexual arousal. NO in turn activates other substances to relax the smooth muscle inside the penis to allow the inflow of blood and an erection to occur. PDE5 inhibitors enhance the effect of NO.

Which drug was first approved and which one lasts for longer?

On March 27 ^th, 1998, Viagra became the first oral pill, and the first PDE5 inhibitor, to be approved by the FDA to treat ED. A generic for Viagra was approved in March 2016  and released in December 2017.

Cialis was first approved for ED on November 21st, 2003. It was the third PDE5 inhibitor to come onto the market (after Levitra [vardenafil]). Cialis has an advantage over Viagra and Levitra in that it lasts for a lot longer – 36 hours, compared with 4-5 hours for Viagra and Levitra. A generic for Cialis was approved in May 2018  and released in September 2018.

How quickly do Cialis and Viagra work and does food have any effect

Cialis generally works within 16 to 45 minutes, and its activity is not affected by food. Viagra generally works within 30 minutes, and its effect may be diminished if taken soon after a high fat meal (which may also delay how fast it works). For this reason, Viagra is best taken on an empty stomach.^1,2,7

Effectiveness of all PDE5 inhibitors is similar; although reported effectiveness of Viagra, at 84% is slightly higher than that of Cialis at 81%.⁷ However, more men prefer Cialis because of its longer duration of effect.

What is the usual dosage of Cialis or Viagra?

Cialis can be taken on an as needed basis, or daily.¹Generally, daily dosages are smaller than as needed doses. Typically, Cialis is taken as a 10mg starting dose, prior to sexual activity. The effects of Cialis will last around 36 hours. The dosage may be increased to 20mg if 10mg is ineffective or reduced to 5mg if side effects are intolerable.¹

When Cialis is taken for daily use, the recommended initial dosage is 2.5mg once daily, or 5mg for people who also have BPH. Timing of the daily dosage does not matter in people using it solely for ED; however, those with BPH are advised to take it at the same time each day. Do not take more than one dose a day but your doctor may consider an increase in dosage from 2.5 to 5mg if ineffective. Side effects of Cialis include headache and indigestion.

Viagra is taken on an as needed basis, at a dose of 50mg, approximately 1 hour before sexual activity (although can be taken from 30 minutes to 4 hours before). The dose may be increased to 100mg if 50mg is ineffective or decreased to 25mg if side effects are intolerable.² Viagra should only be taken once a day even though the effects wear off after approximately 4-5 hours. The main side effects are headache, flushing and indigestion.² Rarely, color perception may be altered with Viagra. This side effect does not happen with Cialis.

Cost of Viagra varies depending on tablet strength but is approximately $24 per tablet for the 50mg strength and $35 for the 100mg strength. Cialis costs approximately $8.50 for the 5mg strength and $28 for the 20mg strength, per tablet.

All PDE5 inhibitors are contraindicated with nitrates. The longer duration of action of Cialis means it is at higher risk for drug interactions, and dosages may need reducing in men with kidney or liver disease. Cialis is not recommended in men who have had a heart attack or stroke within the past 6 months, with either uncontrolled high blood pressure or severely low blood pressure, unstable angina, or other conditions that make sexual activity inadvisable.