Sildenafil (By mouth)


Sildenafil (sil-DEN-a-fil)
Treats erectile dysfunction (trouble having an erection). Helps a man have an erection or have a better erection with his penis during sex. Also treats pulmonary arterial hypertension (high blood pressure in the lungs) in both men and women.

Brand Name(s)

There may be other brand names for this medicine.

Viagra, Revatio

When This Medicine Should Not Be Used

You should not use this medicine if you have had an allergic reaction to sildenafil, or if you are using a nitrate medicine for chest pain (angina). Some examples of nitrate medicines are: isosorbide, nitroglycerin, Imdur®, Nitro-Bid®, Nitro-Dur®, Nitrol® ointment, Nitrolingual® spray, Nitrostat®, and Transderm Nitro®. Some illegal ("street") drugs or "poppers" also contain nitrates, such as amyl nitrate, butyl nitrate, or nitrite.

How to Use This Medicine

  • Your doctor will tell you how much of this medicine to use and how often. Do not use more medicine or use it more often than your doctor tells you to.
  • This medicine comes with patient instructions. Read and follow these instructions carefully. Ask your doctor or pharmacist if you have any questions.
  • Patients with erectile dysfunction:
    • The usual schedule is to take this medicine about 60 minutes (1 hour) before having sex.
    • Do not use this medicine more than one time per day. Always allow at least 24 hours between doses. In some cases, your doctor might tell you not to use this medicine more than once every three days (72 hours).
    • It is best not to eat a high-fat meal before using this medicine. It may take longer for the medicine to work if you have fatty food in your stomach.
  • Patients with pulmonary arterial hypertension:
    • You may take this medicine with or without food.
    • The dose is given three times a day. Each tablet should be spaced 4 to 6 hours apart.
  • Use only the brand of this medicine that your doctor prescribed. Different brands may not work the same way.

How to Store and Dispose of This Medicine

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any leftover medicine after you have finished your treatment. You will also need to throw away old medicine after the expiration date has passed.
  • Keep all medicine away from children and never share your medicine with anyone.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.
  • Make sure your doctor knows if you are using medicine for prostate problems or high blood pressure (such as amlodipine, doxazosin, tamsulosin, terazosin, Cardura®, Flomax®, Minipress®, Norvasc®, or Uroxatral®). Tell your doctor if you are also using cimetidine (Tagamet®), rifampin (Rimactane®), an antibiotic (such as erythromycin, EES®, or Erytab®), medicine to treat HIV or AIDS (such as indinavir, ritonavir, saquinavir, Crixivan®, Kaletra®, or Norvir®), or medicine to treat fungus infections (such as itraconazole, ketoconazole, Nizoral®, or Sporanox®).

Warnings While Using This Medicine

  • Make sure your doctor knows if you are pregnant or breastfeeding, or if you have kidney disease, liver disease, diabetes, high cholesterol, a stomach ulcer, problems with the retina in your eyes (retinitis pigmentosa), or if your penis has an abnormal shape. Also tell your doctor if you are currently on bosentan therapy.
  • Your doctor needs to know if you have heart disease, a bleeding disorder, or problems related to your blood cells. This includes heart valve problems, uneven heartbeats, chest pain, heart failure, high or low blood pressure, sickle cell anemia, or cancer of the blood (such as leukemia or multiple myeloma).
  • Tell your doctor if you have ever had chest pain during sex. Make sure your doctor knows if you have had a stroke or heart attack within the past 3 to 6 months. Your doctor should also know if you smoke or if you are over 50 years old.
  • If you take this medicine for pulmonary arterial hypertension, do not take Viagra® or other similar medicines, such as tadalafil (Cialis®) or vardenafil (Levitra®). Viagra® also contains sildenafil. If you take too much sildenafil or take it together with these medicines, the chance for side effects will be higher.
  • It is important that you tell all of your doctors that you take sildenafil. If you need emergency medical care for a heart problem, it is important that your doctor knows when you last took sildenafil.
  • If you do not have an erection or if you are unhappy with your erection after taking this medicine, tell your doctor. This medicine will not cause an erection unless you are sexually stimulated.
  • This medicine will not protect you from sexually transmitted diseases, including HIV or AIDS. This medicine will not prevent pregnancy and should not be used as a form of birth control. If this is a concern for you or your partner, talk with your doctor.
  • This medicine may cause the penis to become erect at unwanted times, or to stay erect for longer than needed. If you have an erection that lasts longer than 4 hours, call your doctor right away or go to an emergency room.
  • Stop using this medicine and check with your doctor right away if you have a sudden loss of vision or a sudden decrease in hearing or loss of hearing. Hearing problems may also cause dizziness or ringing in the ears. These symptoms could be serious side effects from this medicine.
  • Your doctor needs to know if you are also using any other medicine for high blood pressure. Sildenafil might lower your blood pressure. If your blood pressure gets too low, you might faint or have other health problems.
  • Tell your doctor about all other treatments you are using for erectile dysfunction. Sildenafil should not be used together with other erectile dysfunction medicines.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:
  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing.
  • Change in how much or how often you urinate, or painful urination.
  • Chest pain, especially if it spreads to your jaw or arm.
  • Erection that is painful or lasts longer than 4 hours.
  • Fast, slow, or uneven heartbeat.
  • Fever, or sudden increase in body temperature.
  • Lightheadedness, dizziness, or fainting.
  • Nosebleeds.
  • Numbness, tingling, or burning pain in your hands, arms, legs, or feet.
  • Sudden changes in your vision or changes in how you see colors (especially blue or green).
  • Sudden decrease in hearing or hearing loss, ringing in the ears, or dizziness.
  • Sudden or severe headache.
  • Trouble breathing.
If you notice these less serious side effects, talk with your doctor:
  • Joint or muscle pain.
  • Skin rash.
  • Stuffy or runny nose.
  • Tiredness or weakness.
  • Trouble with sleeping, or feeling anxious.
  • Upset stomach, nausea, diarrhea, or indigestion.
  • Warmth or redness in your face, neck, arms, or upper chest.

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088
Review Date: 2011-02-04 Reviewed By: Keywords: ,
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