What is tadalafil?
Tadalafil is the chemical name of the active ingredient in Cialis®. Cialis® was originally patented and sold by Eli Lilly. It is FDA-approved to treat ED and urinary symptoms due to BPH. After the patent expired in 2018, the FDA gave permission to other drug companies to manufacture a generic version of Cialis®. The FDA requires generic drugs to be bioequivalent to the brand name version. This means that they act the same way in the body and are expected to produce the same effects as the original brand name drug. Generic drugs are generally much cheaper than the original brand name drug, and most drugs prescribed in the US are generic.
What should you know before taking Cialis
Who should not take Cialis® or generic Cialis®?
Do not take Cialis® or generic Cialis® if you:
- take medicines called nitrates (such as nitroglycerin)
- use street drugs called “poppers” such as amyl nitrate or amyl nitrite, and butyl nitrate
- take any medicines called guanylate cyclase stimulators such as riociguat (Adempas)
- are allergic to Cialis® or any of the ingredients in Cialis®. See the end of this section for a complete list of ingredients in Cialis®.
What should I tell my healthcare provider before taking Cialis® or generic Cialis®?
To make sure Cialis® is safe for you, tell your healthcare provider if you have any of the following before you take Cialis® or generic Cialis®:
- Have or have had heart problems such as a heart attack, irregular heartbeat, angina, chest pain, narrowing of the aortic valve, or heart failure
- Have pulmonary hypertension
- Have had a stroke
- Have low blood pressure, or high blood pressure that is not controlled
- Have a deformed penis shape
- Have had an erection that lasted for more than 4 hours
- Have problems with your blood cells such as sickle cell anemia, multiple myeloma, or leukemia
- Have retinitis pigmentosa, a rare genetic (runs in families) eye disease
- Have ever had severe vision loss, including an eye problem called NAION
- Have bleeding problems
- Have or have had stomach or intestinal ulcers
- Have liver problems
- Have kidney problems or are having kidney dialysis
- Have any other medical conditions
Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.
Cialis® and generic Cialis® may affect the way other medicines work, and other medicines may affect the way Cialis® and generic Cialis® works, causing side effects.
Tell your healthcare provider if you take any of the following because these drugs interact with Cialis® and generic Cialis®:
- Medicines called nitrates
- Medicines called guanylate cyclase stimulators such as Adempas® (riociguat)
- Medicines called alpha-blockers such as Hytrin® (terazosin HCl), Flomax® (tamsulosin HCl), Cardura® (doxazosin mesylate), Minipress® (prazosin HCl), Uroxatral® (alfuzosin HCl), Jalyn® (dutasteride and tamsulosin HCl), or Rapaflo® (silodosin). Alpha-blockers are sometimes prescribed for prostate problems or high blood pressure. In some patients, the use of VIAGRA® or generic VIAGRA® with alpha-blockers can lead to a drop in blood pressure or to fainting
- Medicines called HIV protease inhibitors, such as ritonavir (Norvir®), indinavir sulfate (Crixivan®), saquinavir (Fortovase® or Invirase®), or atazanavir sulfate (Reyataz®)
- Oral antifungal medicines, such as ketoconazole (Nizoral®) and itraconazole (Sporanox®)
- Antibiotics, such as clarithromycin (Biaxin®), telithromycin (Ketek®), or erythromycin
- Other medicines that treat high blood pressure
- Other medicines or treatments for ED
- Adcirca® (tadalafil) is used to treat a rare disease called pulmonary arterial hypertension (PAH) and has the same active ingredient as Cialis®. Cialis® and generic Cialis® should not be used with Adcirca® or with other PAH treatments containing sildenafil or any other PDE5 inhibitors (such as Revatio® [sildenafil citrate])
Ask your healthcare provider or pharmacist for a list of these medicines, if you are not sure.
Know the medicines you take. Keep a list of them to show to your healthcare provider and pharmacist when you get a new medicine.
Cialis® side effects
What are the possible side effects of Cialis® and generic Cialis®?
Cialis® and generic Cialis® can cause serious side effects. Rarely reported side effects include:
- an erection that will not go away (priapism). If you have an erection that lasts more than 4 hours, get medical help right away. If it is not treated right away, priapism can permanently damage your penis.
- sudden vision loss in one or both eyes. Sudden vision loss in one or both eyes can be a sign of a serious eye problem called non-arteritic anterior ischemic optic neuropathy (NAION). It is uncertain whether PDE5 inhibitors directly cause the vision loss. Stop taking Cialis® and call your healthcare provider right away if you have sudden vision loss in one or both eyes.
- sudden hearing decrease or hearing loss. Some people may also have ringing in their ears (tinnitus) or dizziness. If you have these symptoms, stop takingCialis® or generic Cialis® and contact a doctor right away.
The most common side effects of Viagra® and generic Cialis® are:
- upset stomach
- abnormal vision, such as changes in color vision (such as having a blue color tinge) and blurred vision
- stuffy or runny nose
- muscle pain
In addition, heart attack, stroke, irregular heartbeats and death have happened rarely in men taking Cialis® . Most, but not all, of these men had heart problems before taking Cialis® . It is not known if Cialis® caused these problems.
Tell your healthcare provider if you have any side effect that bothers you or does not go away.
These are not all the possible side effects of Cialis® and generic Cialis® . For more information, ask your healthcare provider or pharmacist.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What happens if I overdose?
Taking more than the recommended amount of Cialis® or generic Cialis® greatly increases your risk of side effects, including severe ones that can be dangerous, such as severe low blood pressure or an erection that won’t go away even after 4 or more hours (priapism). Never take more than the amount prescribed to you by your doctor or nurse practitioner. If you have any severe side effects after taking more than the recommended amount, or even after taking the amount of medicine prescribed to you, seek out emergency medical attention immediately.