Frequently Asked Questions
Here are the frequently asked questions regarding Sildenafil (Viagra®).
What is this drug used for?
It is used to treat erectile dysfunction (ED).
It is used to treat high blood pressure in the lungs.
It may also be prescribed for other reasons. Talk to your doctor for more information.
What do I need to tell my doctor before I take this drug?
For all uses of this drug:
Inform your doctor if you are allergic to this drug, any of its ingredients, or other drugs, foods, or substances. Share details about any allergic reactions you’ve had, including symptoms.
Notify your doctor if you have a condition called pulmonary veno-occlusive disease (PVOD).
Tell your doctor if you have certain hereditary eye problems, such as retinitis pigmentosa.
Avoid this drug if you use substances called "poppers" (e.g., amyl nitrite or butyl nitrite).
Inform your doctor if you are taking any of the following drugs:
Isosorbide dinitrate
Isosorbide mononitrate
Nitroglycerin
Riociguat
Ritonavir
Vericiguat
Inform your doctor if you are taking itraconazole or ketoconazole.
Do not take this drug if you are already using another medication with the same active ingredient.
Avoid taking this drug with other medications for erectile dysfunction (ED) or high blood pressure in the lungs.
For erectile dysfunction (ED):
Inform your doctor if you have been advised not to engage in sexual activity due to health concerns.
This drug is not approved for use in females.
This drug is not approved for use in children.
Note:
This is not a comprehensive list of drugs or health conditions that may interact with this drug.
⚠️ Important:
Inform your doctor and pharmacist about all medications you are taking, including prescription drugs, over-the-counter products, supplements, and vitamins.
Ensure it is safe for you to take this drug in combination with your other medications and health conditions.
Do not start, stop, or change the dosage of any medication without consulting your doctor.
What are some things I need to know or do while taking this drug?
For all uses of this drug:
Inform all your healthcare providers (doctors, nurses, pharmacists, dentists) that you are taking this drug.
Avoid driving or engaging in tasks requiring alertness until you know how this drug affects you.
To reduce the risk of dizziness or fainting, rise slowly from sitting or lying positions. Be cautious on stairs.
Discuss alcohol consumption with your doctor before using this medication.
Rarely, serious side effects such as abnormal heart rhythms, heart attack, stroke, lung bleeding, or dangerously high blood pressure may occur. These effects are more likely in individuals with preexisting heart conditions. Consult your doctor if you have concerns.
This drug has been linked to a rare but severe eye condition that may cause vision changes or permanent vision loss. Discuss this risk with your doctor.
Inform your doctor if you have sickle cell disease.
Older adults (65+) may experience increased side effects; use this drug with caution.
For erectile dysfunction (ED):
This drug does not protect against sexually transmitted diseases, such as HIV or hepatitis. Use a latex or polyurethane condom during sexual activity.
What are some side effects I need to report to my doctor immediately?
Seek medical attention if you experience:
Signs of an allergic reaction, such as:
Rash
Hives
Itching
Red, swollen, blistered, or peeling skin (with or without fever)
Wheezing or chest tightness
Difficulty breathing, swallowing, or talking
Swelling of the mouth, face, lips, tongue, or throat
Chest pain or pressure
Fast or abnormal heartbeat
Severe dizziness or fainting
Severe nausea or vomiting
Weakness on one side of the body, difficulty speaking, balance issues, or facial drooping
Changes in vision or loss of vision
Ringing in the ears or hearing loss
New or worsening trouble breathing
Swelling in the arms or legs
Fever
Unexplained bruising or bleeding
Painful erection or an erection lasting more than 4 hours (seek help immediately to avoid permanent damage).
Note:
While rare, some side effects may be severe or life-threatening. Contact your doctor or seek emergency care immediately if you experience these symptoms.
What are some other side effects of this drug?
Common side effects:
Flushing
Headache
Heartburn
Upset stomach
Runny or stuffy nose
Muscle pain
Additional side effects for ED:
Back pain
Additional side effects for PAH (pulmonary arterial hypertension):
Diarrhea
Nosebleeds
Back, arm, or leg pain
Note:
This is not a complete list of side effects. If you experience bothersome or persistent side effects, consult your doctor.
What should I do if I miss a dose?
For erectile dysfunction (ED):
This drug is taken as needed.
Do not take it more often than prescribed.
Avoid taking more than one dose in a single day.
How should I store and dispose of this drug?
Tablets:
Store at room temperature in a dry location.
Do not store in the bathroom.
Keep all medications out of reach of children and pets.
Dispose of unused or expired medications properly.
Do not flush medications down the toilet or drain unless instructed to do so.
Consult your pharmacist for information on drug take-back programs.
Please Note:
If your symptoms worsen or do not improve, contact your doctor.
Do not share your medication with others or take someone else’s medication.
For more information, ask your healthcare provider.
In case of overdose, contact a poison control center or seek emergency medical care. Be prepared to provide details of the drug, dosage, and timing.