Sildenafil Sildenafil is an oral tablet used to treat erectile dysfunction. By expanding blood vessels throughout the penile tissue, Sildenafil helps to sustain and maintain an erection. Read more about erectile dysfunction.
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How to use this information 
This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective or appropriate for you. This information is not individual medical advice and does not substitute for the advice of a medical provider. If you have any questions, go to your patient dashboard and request a callback for complete information about this product and your specific health needs.
Medication name

Sildenafil (ERECTILE DYSFUNCTION) - ORAL\ (sil-DEN-a-fil)


What you should know about Sildenafil
  • Sildenafil is used to treat erectile dysfunction (ED). In combination with sexual stimulation, the medication works by increasing blood flow to the penis to help a man get and keep an erection.
  • This drug does not protect against sexually transmitted diseases such as HIV, hepatitis B, gonorrhea and syphilis, so it’s important to practice "safe sex" using latex condoms. 
  • Do not take this medication with any other product that contains Sildenafil or other medications for erectile dysfunction or pulmonary hypertension such as Tadalafil and Vardenafil.
  • Read the Patient Information Leaflet provided by your pharmacist before you start taking Sildenafil and each time you get a refill. If you have any questions, request a medical providercallback from your patient dashboard for more details.
How to take Sildenafil
  • Take Sildenafil by mouth as directed, usually as needed. The medication should be taken least 30 minutes—but no more than 4 hours—before sexual activity (1 hour before is the most effective). Do not take more than once daily.
  • Your prescribed dosage is based on your medical condition, response to treatment and other medications you may be taking. Be sure to tell your medical providerand pharmacist about all the products you use, including prescription drugs, nonprescription drugs and herbal products.
  • A high fat meal may delay the medication’s effects. 
  • If your condition does not improve, request a medical provider callback.
Potential side effects
  • Dizziness, headache, flushing or upset stomach may occur. Vision changes such as increased sensitivity to light, blurred vision or trouble telling blue and green colors apart may also occur. If any of these effects last or get worse, seek medical care immediately. If your symptoms are minor, request a medical provider callback in your patient dashboard.
  • To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.
  • Remember that this medication has been prescribed because your medical provider has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
  • Sexual activity may put extra strain on your heart, especially if you have heart problems. If you have heart problems and experience any of the following serious side effects while having sex, stop and get medical help right away: severe dizziness, fainting, chest/jaw/left arm pain or nausea.
  • In rare cases, sudden decreased vision, including permanent blindness in one or both eyes (NAION) may occur. If this serious problem occurs, stop taking Sildenafil and get medical help right away. You have a slightly greater chance of developing NAION if you have:

    • Heart disease
    • Diabetes
    • High cholesterol 
    • Certain other eye problems, including "crowded disk"
    • High blood pressure
    • Are over 50 
    • Are a smoker
  • In rare cases, a sudden decrease or loss of hearing—sometimes combined with ringing in the ears and dizziness—may occur. If you experience this, stop taking Sildenafil and get medical help right away.
  • In the rare event you experience a priapism, or a painful or prolonged erection lasting 4 or more hours, stop using this drug and seek emergency medical help right away to prevent permanent complications.
  • A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness or trouble breathing.
  • This is not a complete list of possible side effects. If you notice other effects not listed above, contact us for medical advice about side effects. You may also report side effects to the FDA at 1-800-FDA-1088 or at
Precautions to be aware of
  • Before taking Sildenafil, contact us if you are allergic to it or have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems.
  • During your consultation, provide us with your medical history, especially of issues such as:

    • Heart problems such as heart attack or life-threatening irregular heartbeat in the past 6 months
    • Chest pain/angina
    • Heart failure
    • Stroke in the past 6 months
    • Kidney disease
    • Liver disease
    • High or low blood pressure
    • Dehydration
    • Penis conditions such as angulation, fibrosis/scarring or Peyronie's disease
    • History of painful/prolonged erection (priapism)
    • Conditions that may increase the risk of priapism such as sickle cell anemia, leukemia and multiple myeloma
    • Eye problems such as retinitis pigmentosa, sudden decreased vision and NAION
  • This drug may make you dizzy or cause vision problems, especially when combined with alcohol or marijuana (cannabis). Do not drive, use machinery or do anything that requires alertness or clear vision until you can do so safely. Limit alcoholic beverages, as they can worsen symptoms. Let us know if you are using marijuana. 
  • Discontinue medication if you experience persistent lightheadedness. Monitor your blood pressure regularly to make sure it’s not too low. 
  • Before having surgery, tell your prescriber about all the products you use, including prescription drugs, nonprescription drugs and herbal products.
Drug interactions
  • Drug interactions may change how your medications work or increase your risk for serious side effects.
  • This webpage does not contain all possible drug interactions. Keep a list of all the products you use, including prescription/nonprescription drugs and herbal products, and share it with your prescriber. 
  • Do not start, stop or change the dosage of any medicines without your medical provider's approval.
  • Sildenafil can cause a serious drop in your blood pressure when used with nitrates possibly leading to dizziness, fainting and in rare cases heart attack or stroke. Do not use Sildenafil with any of the following: certain drugs used to treat chest pain/angina, including nitrates such as nitroglycerin and Isosorbide, amyl nitrite and recreational drugs containing amyl nitrate, butyl nitrite or nitroglycerin known as "poppers.”
  • If you are also taking an alpha blocker medication like Doxazosin or Tamsulosin to treat an enlarged prostate (BPH) or high blood pressure, your blood pressure may get too low—putting you at risk for dizziness or fainting. Your medical provider may start treatment with a lower dose of Sildenafil to minimize your risk of low blood pressure.
  • Other medications can affect the removal of Sildenafil from your body, which may affect how Sildenafil works. Examples include:

    • Azole antifungals such as Itraconazole and Ketoconazole
    • Macrolide antibiotics such as Clarithromycin and Erythromycin
    • HIV protease inhibitors such as Ritonavir and Saquinavir
    • Mifepristone
    • Rifampin
  • Riociguat may interact with this drug.
  • Do not take this medication with any other product that contains Sildenafil or other similar medications for conditions like pulmonary hypertension such as Tadalafil or Vardenafil.
What to do in the event of an overdose

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call your local poison control center at 1-800-222-1222 right away. Symptoms of overdose may include severe dizziness, fainting or painful/prolonged erection.

Additional notes

Do not share this medication with others.

What to do if you miss a dose

Not applicable.

How to store this medication
  • Store at room temperature away from light and moisture.
  • Do not store in the bathroom. Keep all medications away from children and pets.
  • Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Generic Name
Brand Name
Drug Class
PDE-5 inhibitor

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