Tadalafil (Cialis®)

OncoLink Team
Last Modified: December 10, 2015

Pronounced: ta-DAL-a-fil

Classification: Phosphodiesterase Inhibitor

About Tadalafil

Tadalafil is a medication that is taken before sexual activity and allows men with erectile dysfunction (ED) to achieve and maintain an erection. ED or impotence is a condition in which a man is unable to achieve or maintain an erection long enough for sexual intercourse. This can be a result of medical conditions such as high blood pressure, diabetes, prostate problems, and heart disease, or a side effect of the medications typically taken for these conditions. Personal lifestyle factors such as stress, alcohol and/or tobacco use can also play a contributing role. During surgery or radiation to the pelvic area (including prostate, bladder, and rectal procedures), damage can occur to the nerves that supply the penis. This can result in either temporary or permanent impotence. Some surgeons perform "nerve-sparing" surgeries in an attempt to preserve erectile function. Even in these cases, however, the nerves will suffer some injury, and it can take 18-24 months or longer for erectile function to return. These men should be treated aggressively with oral or injectable medications for ED in order to speed recovery of the nerves and to prevent muscle wasting in the penis.

How to take Tadalafil

  • Tadalafil is taken by mouth up to once a day, at least 30-60 minutes before sexual activity, and works for up to 36 hours. It can be taken with or without food.
  • Your doctor will determine the dose that is best for you. Some men will be prescribed a lower dose to take every day. You should not adjust your dose without talking to your doctor first.
  • Men who take tadalafil will not have an erection without sexual stimulation. This drug is not an aphrodisiac and does not affect libido or desire. Having multiple intercourse sessions with one dose has not been studied.
  • Do not drink excess alcohol while taking tadalafil (for example, more than 5 glasses of wine or 5 alcoholic drinks).
  • Men who take nitrates, such as nitroglycerin, Nitro-Bid, Isordil, or Deponit should not take tadalafil.
  • Men who take Cardura, Flomax, or Hytrin for urinary symptoms should not take tadalafil.
  • This medication can affect how other medications work. Be sure your provider and pharmacist know all the medication (prescription and over-the-counter) and supplements you take.

Storage and Handling     

Store your medication in the original, labeled container at room temperature and in a dry location (unless otherwise directed by your healthcare provider or pharmacist). This medication should not be stored in a pillbox since it should only be taken prior to sexual activity. Keep containers out of reach of children and pets.

Where do I get this medication?

Tadalafil is available through most pharmacies. 

Insurance Information

This medication may be covered under your prescription drug plan. Patient assistance may be available to qualifying individuals without prescription drug coverage through the pharmaceutical company that makes the medication. Your care team can help you find these resources, if they are available.

Possible Side Effects of Tadalafil

There are a few side effects experienced with tadalafil. Talk to your doctor, nurse or pharmacist if you have concerns about these side effects. Do not take a higher dose of tadalafil than your provider orders for you.

The most common side effects include:

Headache, facial flushing, stuffy or runny nose, and upset stomach can occur. Some patients experience back pain or muscle aches that typically occur 12 to 24 hours after taking tadalafil. This typically resolves on its own, after 48 hours. If you have pain that persists, contact your doctor.

Less frequent side effects include blurry vision, a bluish hue to the field of vision, difficulty telling the difference between the colors blue and green, a sensitivity to light, or a sudden loss of vision or hearing.

If you experience any of the following while using tadalafil, you should seek immediate medical attention:

  • An erection lasting more than 4 hours
  • Chest, arm or neck pain, or nausea during sexual activity
  • Sudden loss of vision or hearing
  • You develop an allergic reaction (rash, hives, swelling of the lips, tongue or throat, difficulty breathing)

Reproductive Concerns

Remember, tadalafil does not protect against sexually transmitted diseases, nor does it prevent pregnancy. Effective birth control is recommended during cancer treatment. Even if you are not producing sperm, you could still be fertile and conceive. 



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