sildenafil
Sildenafil (Viagra) is taken by mouth to treat erectile dysfunction (ED). You take it only as needed, typically about an hour before sexual activity (but you can take it anywhere between 30 minutes to 4 hours before sex). Don't take sildenafil (Viagra) more than once a day because doing so can put you at higher risk for serious side effects, such as vision loss or low blood pressure. It's available as a lower-cost generic.
What is Sildenafil (Viagra)?
What is Sildenafil (Viagra) used for?
Erectile dysfunction (ED)
How Sildenafil (Viagra) works
Sildenafil (Viagra) is a phosphodiesterase-5 (PDE-5) inhibitor. PDE-5 is a protein in your body that breaks down the molecules that normally cause an erection. When it blocks PDE-5, sildenafil (Viagra) helps an erection occur by allowing certain muscles in the penis to relax and the penis to fill with blood.
Drug Facts
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What are the side effects of Sildenafil (Viagra)?
Common Side Effects
- Headache (16-28%)
- Flushing (10-19%)
- Indigestion (3-17%)
- Changes in vision or light sensitivity (1-11%)
- Stuffy nose (4-9%)
Other Side Effects
- Back pain
- Dizziness
- Muscle ache
- Nausea
- Rash
Serious Side Effects
- Erection lasting for more than 4 hours
- Vision loss
- Dangerously low blood pressure: feeling faint or weak, dizziness, blurry vision, feeling confused
Source: DailyMed
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The following side effects have also been reported
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Less common
Bladder pain
burning feeling in the chest or stomach
burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
cloudy or bloody urine
dizziness
increased frequency of urination
indigestion
pain on urination
stomach upset
tenderness in the stomach area
Rare
Abnormal vision
behavior change similar to drunkenness
bleeding of the eye
blurred vision
bone pain
breast enlargement
chills
cold sweats
confusion
convulsions (seizures)
cool and pale skin
deafness or hearing loss
decrease in amount of urine or the frequency of urination
decreased vision
difficulty in concentrating
dizziness or lightheadedness, especially when getting up suddenly from a lying or sitting position
double vision
drowsiness
dryness, redness, scaling, or peeling of the skin
excessive hunger
fainting or faintness
fast, irregular, or pounding heartbeat
feeling of something in the eye
fever or chills
headache (severe or continuing)
increase in the size of the pupil
increased sweating
increased thirst
lower back or side pain
migraine headache
nausea (severe or continuing)
nervousness
nightmares
numbness of the hands
painful, swollen joints
prolonged, painful erection of penis
redness, burning, or swelling of the eyes
redness, itching, or tearing of the eyes
restless sleep
seeing shades of colors differently than before
sensitivity to light
shakiness
skin lesions with swelling
skin paleness
skin ulcers
slurred speech
sudden weakness
swelling of the face, hands, feet, or lower legs
trouble breathing
twitching of the muscles
unusual feeling of burning or stinging of the skin
unusual tiredness or weakness
vision changes
vision loss, temporary
Incidence not known
Blindness
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
Aches or pains in the muscles
bloody nose
difficult or labored breathing
flushing
headache
pain or tenderness around the eyes and cheekbones
redness of the skin
stomach discomfort following meals
stuffy or runny nose
trouble sleeping
unusually warm skin
Rare
Abdominal or stomach pain
abnormal dreams
clumsiness or unsteadiness
diarrhea or stomach cramps (severe or continuing)
difficulty in swallowing
ear pain
increased amount of saliva
increased skin sensitivity
lack of coordination
loss of bladder control
mental depression
numbness or tingling of the hands, legs, or feet
rectal bleeding
redness or irritation of the tongue
redness, soreness, swelling, or bleeding of the gums
ringing or buzzing in the ears
sensation of motion, usually whirling, either of one's self or of one's surroundings
sexual problems in men (continuing), including failure to experience a sexual orgasm
sleepiness
sores in the mouth and on the lips
tense muscles
trembling and shaking
vomiting
waking to urinate at night
worsening of asthma
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Pros and cons of Sildenafil (Viagra)
Pros
One of the first-choice medications for treating ED
Taken only when you need it
Can take it 30 minutes to 4 hours before sexual activity
Available as a lower-cost generic
Comes in different strengths, so you and your provider can find which works best for you
Cons
Can take some time to work, so some planning is needed
Can't be taken if you've had a heart attack or stroke in the past 6 months
Can't be used if you've recently taken nitrates like isosorbide dinitrate (Isordil) or nitroglycerin (Nitrostat)
Higher risk for side effects, such as headaches and flushing, for people age 65 years and older
Pharmacist tips for Sildenafil (Viagra)
It's best to take sildenafil (Viagra) about 1 hour before sex, but you can take it anywhere between 30 minutes and 4 hours before you need it.
You can take sildenafil (Viagra) with or without food, but it works faster when you take it on an empty stomach.
Don't take more than one dose of sildenafil (Viagra) per day. Doing so can raise your risk of serious side effects, such as dangerously low blood pressure and vision loss.
If you have an erection for more than 4 hours or if you feel pain with the erection, go to the emergency department or call your provider right away. If left untreated, this can lead to permanent damage to your penis.
If your provider prescribes you any blood pressure medications or heart medications, let them know you're taking sildenafil (Viagra). You can't take sildenafil (Viagra) with certain medications, such as isosorbide mononitrate (Monoket) because doing so can cause your blood pressure to drop dangerously low.
Sildenafil (Viagra) doesn't stop the spread of sexually transmitted diseases (STDs) like herpes or HIV. Practice safe sex by using a latex or polyurethane condom.
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Frequently asked questions about Sildenafil (Viagra)
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What are the risks and warnings for Sildenafil (Viagra)?
Sildenafil (Viagra) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Heart problems
Risk factors: Existing heart condition | Recent heart attack or stroke in past 6 months | High or low blood pressure
Let your provider know if you have any heart conditions before starting sildenafil (Viagra). Sexual activity, and therefore sildenafil (Viagra), isn't recommended for people with certain heart-related conditions, such as very serious heart failure. Also, sildenafil (Viagra) hasn't been studied in people who have certain conditions, such as recent heart attacks or strokes. If you have a heart condition, ask your provider whether sildenafil (Viagra) is safe for you.
Low blood pressure
Risk factors: Taking alpha blockers | Taking medications for high blood pressure or chest pain (angina) | Taking ritonavir (Norvir)
Taking sildenafil (Viagra) with certain medications, such as alpha blockers, medications for high blood pressure, or ritonavir (Norvir) can cause your blood pressure to drop too low. If you take any of these medications, talk with your provider to see if sildenafil (Viagra) is safe for you. If your provider says that you can take sildenafil (Viagra), they might recommend that you check your blood pressure regularly. Be very careful getting up from a sitting or lying down position since this can make you feel dizzy and more likely to fall. You should never take sildenafil (Viagra) when taking nitrate medication for chest pain (angina) because it can cause your blood pressure to drop suddenly to unsafe levels.
Prolonged or painful erection (priapism)
Risk factors: Medical conditions that affect the penis | Sickle cell anemia | Multiple myeloma | Leukemia
Some people who took sildenafil (Viagra) reported having an erection that lasted for more than 4 hours (priapism). This side effect is rare. But if it's not treated in time, it can lead to permanent damage to your penis. You're at higher risk for these side effects if you have other conditions affecting your penis, or if you have sickle cell anemia, multiple myeloma, or leukemia. Get medical help right away if you have an erection that lasts longer than 4 hours or if you feel pain during an erection.
Vision changes
Risk factors: Age 50 years or older | "Crowded" optic disc | Blood vessel problems in the eye
If you suddenly notice changes in your vision in one or both eyes, go to the emergency room or call your provider right away. Although this is rare, sildenafil (Viagra) can cause permanent eye damage. If your provider has told you that you have a "crowded" optic disc, you might be at higher risk for vision changes with sildenafil (Viagra). Tell your provider about your full medical history before taking sildenafil (Viagra).
Hearing loss
Some people who took sildenafil (Viagra) reported experiencing hearing loss. And it sometimes happens along with ringing in the ears (tinnitus) and dizziness. Go to the emergency room or call your provider right away if you notice changes in your hearing in one or both ears.
Interactions with other medications
Risk factors: Age 65 years or older | Liver problems | Kidney problems | Taking nitrate medications | Taking blood pressure medications | Taking alpha blockers | Taking certain antifungals or antivirals
Sildenafil (Viagra) can have serious interactions with certain medications. It's important that you let your provider know about all the medications you're taking before you start sildenafil (Viagra). For example, you shouldn't take sildenafil (Viagra) with nitrate medications because this combination can cause your blood pressure to drop dangerously low. If you're taking other blood pressure medications, your provider might not recommend sildenafil (Viagra) until your blood pressure is under control. Taking sildenafil (Viagra) with medications, like oral azole antifungals and ritonavir (Norvir), can put you at higher risk for side effects, such as headaches, flushing, and vision changes.
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Sildenafil (Viagra) dosage forms
Typical dosing for Sildenafil (Viagra)
The typical dose is to take 50 mg of sildenafil (Viagra) by mouth, about 1 hour before sex, as needed. The maximum recommended dose is 100 mg. Don't take sildenafil (Viagra) more than once daily (at any dose).
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Sildenafil (Viagra) Reviews
GoodRx has partnered with PatientsLikeMe to provide reviews on the different aspects of Sildenafil (Viagra).
Effectiveness
Learn more about the effectiveness of Sildenafil (Viagra) based on real life experiences.
Overall Rating
Based on 14 people taking this medication
4.2
Effectiveness by condition:
erectile dysfunction10 reviews
3.8
pulmonary hypertension4 reviews
4.7
Severity of side effects
Based on 28 people taking this medication
0%
50%
100%
Top side effects
Headaches
18%
Acid reflux
4%
Nasal congestion
4%
Vision abnormalities (halos/floaters/snow)
4%
Upset stomach
4%
Reasons people stopped taking Sildenafil (Viagra)
Based on 34 people who have taken this medication
Expense
39%
Did not seem to work
27%
Doctor's advice
9%
Other
9%
Side effects too severe
9%
Change in health plan coverage
3%
Course of treatment ended
3%
Personal research
3%
How long people take Sildenafil (Viagra)
Based on 76 people taking this medication
0%
50%
100%
Interactions between Sildenafil (Viagra) and other drugs
More on Sildenafil (Viagra) interactions
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
- Amprenavir
- Amyl Nitrite
- Atazanavir
- Boceprevir
- Cobicistat
- Darunavir
- Erythrityl Tetranitrate
- Fosamprenavir
- Indinavir
- Isosorbide Dinitrate
- Isosorbide Mononitrate
- Lopinavir
- Molsidomine
- Nelfinavir
- Nitroglycerin
- Nitroprusside
- Pentaerythritol Tetranitrate
- Propatyl Nitrate
- Riociguat
- Ritonavir
- Saquinavir
- Telaprevir
- Tipranavir
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Cannabis
- Ceritinib
- Clarithromycin
- Conivaptan
- Dihydrocodeine
- Duvelisib
- Fluconazole
- Fosnetupitant
- Idelalisib
- Itraconazole
- Ivosidenib
- Larotrectinib
- Lefamulin
- Lorlatinib
- Lumacaftor
- Nefazodone
- Netupitant
- Simeprevir
- Telithromycin
- Voriconazole
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Alfuzosin
- Bosentan
- Bunazosin
- Ciprofloxacin
- Delavirdine
- Doxazosin
- Erythromycin
- Etravirine
- Ketoconazole
- Moxisylyte
- Nebivolol
- Prazosin
- Rifapentine
- Silodosin
- Tamsulosin
- Terazosin
- Trimazosin
How much does Sildenafil (Viagra) cost?
Sildenafil (Viagra) contraindications
Taking a nitrate medication for chest pain (angina)
Taking guanylate cyclase (GC) stimulators, such as Adempas (riociguat)
What are alternatives to Sildenafil (Viagra)?
Erectile dysfunction
Benign prostatic hyperplasia (BPH)
What is the latest news about Sildenafil (Viagra)?
Sildenafil (Viagra) images
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