Viagra is a brand name (trade name) for the drug sildenafil. Viagra (sildenafil) works by blocking an enzyme called cGMP-specific phosphodiesterase type-5 (PDE-5). This enzyme breaks cGMP, a substance that relaxes smooth muscles. By blocking PDE-5, smooth muscle cGMP levels rise, promoting muscular relaxation and vasodilation (a widening of blood vessels).

PDE-5 levels are high in the penis, lungs, and retina. PDE-5 is also found in the smooth muscle cells of blood vessels and muscles throughout the body. Viagra is a drug used to treat erectile dysfunction (impotence) in men.

Read the information provided by your pharmacist before you start taking sildenafil each time you get a refill. If you have any concerns, consult your doctor or pharmacist.

Take this medication by mouth as advised by your doctor to treat erectile dysfunction-ED. Take sildenafil at least 30 minutes before sexual activity, but no more than 4 hours (1 hour before is the most effective). Take no more than once each day.

The dosage of Viagra is determined by your medical condition, treatment response, and any other medications you may be taking. Inform your doctor and pharmacist about all of the products you use (including prescription drugs, nonprescription drugs, and herbal products). If your situation does not improve, consult your doctor.

There are some side effects of using Viagra that you need to notice. It is possible to have dizziness, headache, flushing, or stomach trouble. Vision changes such as increased sensitivity to light, blurred vision, or difficulty distinguishing between blue and green colors may also happen. Inform your doctor or pharmacist right once if any of these effects continue or worsen.

Remember that your doctor has prescribed this medication as your doctor has judged that the benefit to you is greater than the risk of side effects. Many persons who use this drug have no serious side effects.

Sexual activity may put greater strain on your heart, particularly if you have heart problems. If you have a heart problem and develop any of the following dangerous side effects while having sex, stop immediately and seek medical assistance: extreme dizziness, fainting, chest/jaw/left arm pain, nausea.

Rarely, one or both eyes may experience sudden decreased vision, including irreversible blindness. If this significant condition develops, stop sildenafil immediately and seek medical care. Rarely, a sudden decrease or loss of hearing may occur, along with ringing in the ears and dizziness. If you have any of these side effects, stop taking sildenafil immediately and consult a doctor.

If you get a painful or lengthy erection that lasts 4 hours or more, stop using this drug immediately and seek medical help. It is uncommon for this drug to cause a severe allergic reaction. However, if you detect any symptoms of a major allergic response, such as a rash, itching/swelling (particularly of the face/tongue/throat), extreme dizziness, or difficulty breathing, get medical help right away.

This is not a complete list of potential negative effects of Viagra. Contact your doctor or pharmacist if you experience any other side effects not listed above.

Most of Viagra's mild side effects disappear within a few hours after taking your dose or are readily relieved. For example, lying down and resting can typically relieve headaches, flushes, and dizziness. Avoiding alcohol will also aid in the reduction of these negative effects. Turning off any bright lights around you can also help with headaches and light sensitivity. If you experience bothersome headaches while using Viagra, consult your doctor or pharmacist for a pain medication that is safe for you to take.

If you get indigestion after using Viagra, try taking it with a snack or light meal. Just keep in mind that if you do this, Viagra may take slightly longer to kick in. (This is especially true if you combine your dose with a high-fat meal.) If your indigestion is bothering you, ask your doctor or pharmacist for medicine to assist in relieving your symptoms.

Remember that certain side effects are more common with greater Viagra doses. Headaches, flushing, indigestion, nasal congestion, and changes in vision are among the side effects. If these side effects worry you, talk to your doctor about taking a lower dose of Viagra.

Take Viagra no more than once each day. The average recommended dosage is 50mg (range 25mg to 100mg), taken an hour before sexual activity as needed. It can, however, be taken anytime between 30 minutes and four hours before sexual activity. Do not take more than the maximum advised dose.

While taking Viagra, avoid consuming grapefruit or grapefruit products.

Always with your doctor before beginning any ED medication. Some ED drugs are not appropriate for men who have specific medical issues, and your doctor can recommend an alternative.

If you experience dizziness or nausea during sexual activity, or if you get discomfort, numbness, or tingling in your chest, arms, neck, or jaw, call your doctor right away.

Never take another ED medicine while taking Viagra. Do not take Viagra if you are also taking Revatio, and vice versa.

Seek immediate medical attention if you experience an allergic reaction, acute eyesight loss, or painful erections lasting longer than four hours.

Drinking alcohol after taking Viagra may cause blood pressure to drop and sexual performance to suffer.

Viagra is not intended for female use.

Via­gra isn't magic; it does need sex­ual stim­u­la­tion to produce an erec­tion, and it may not work the first time. Allow at least two to three attempts to verify whether it is working for you. If you're afraid it won't work with your partner, try it on your own and self-stim­u­lat­ing first.

Viagra normally begins to work between 30 and 60 minutes after intake. However, Viagra does not cause an erection. Instead, in order for the medicine to operate, you must be sexually stimulated.

Viagra continues to work in your body for up to 5 hours. This means that if you're aroused, you should be able to maintain an erection for up to 4 hours after taking a Viagra dose.

Even if Viagra works for several hours in your body, your erection should not remain this long. In reality, Viagra can occasionally cause priapism. You experience a long-lasting and occasionally painful erection with this disorder. Priapism is a medical issue that must be treated immediately. If left untreated, the illness can cause irreversible erectile dysfunction (ED) by damaging the tissues of your penis.

If your erection lasts more than four hours, go to the nearest emergency room or dial 911.