Drug Notes

Sildenafil (By mouth)

Sildenafil (sil-DEN-a-fil)

Treats erectile dysfunction. Also treats pulmonary arterial hypertension (high blood pressure in the lungs).

Brand Name(s):

Revatio, Viagra

When This Medicine Should Not Be Used:

How to Use This Medicine:

Tablet, Liquid

• Your doctor will tell you how much medicine to use. Do not use more than directed.
• For erectile dysfunction: Take this medicine about 1 hour before you have sex. Do not take it more than once a day. Always allow at least 24 hours between doses.
• For pulmonary arterial hypertension:
  • Take this medicine 3 times a day, 4 to 6 hours apart.
  • If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
• Oral liquid: Shake the bottle well for at least 10 seconds. Use the oral syringe provided in the package to measure each dose. Wash the syringe after each use.
• Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
• Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
• Throw away any unused mixed oral liquid after 60 days.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Do not use this medicine if you also use riociguat or a nitrate medicine. Do not take other medicines that contain sildenafil or similar medicines, such as tadalafil or vardenafil.
• Some medicines can affect how sildenafil works. Tell your doctor if you are using any of the following:
  • Amlodipine, atazanavir, bosentan, cimetidine, erythromycin, indinavir, itraconazole, ketoconazole, rifampin, ritonavir, saquinavir
  • Medicine for prostate problems or high blood pressure (including alfuzosin, doxazosin, prazosin, silodosin, tamsulosin, terazosin)

Warnings While Using This Medicine:

• Tell your doctor if you are pregnant or breastfeeding, or if you have kidney disease, liver disease, pulmonary veno-occlusive disease, diabetes, bleeding problems, leukemia, multiple myeloma, sickle cell anemia, a stomach ulcer, or eye problems. Tell your doctor if you have angina or chest pain during sex, heart disease, heart rhythm problems, high or low blood pressure, or a history of heart attack or stroke. Also tell your doctor if you smoke.
• Tell any doctor who treats you that you take sildenafil.
• This medicine may cause the following problems:
  • Low blood pressure (especially if taken with other medicines that lower blood pressure)
  • Heart problems
  • Painful or prolonged erection
  • Vision or hearing problems
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

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
• Chest pain, trouble breathing, sudden or severe headache
• Fast, slow, pounding, or uneven heartbeat
• Lightheadedness, fainting
• Painful erection or an erection that lasts longer than 4 hours
• Sudden loss of vision
• Sudden decrease in hearing or hearing loss, ringing in the ears, dizziness

If you notice these less serious side effects, talk with your doctor:

• Headache
• Nosebleeds
• Stuffy or runny nose
• Upset stomach
• 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

Last Updated: 1/27/2017