How it’s taken: Generic Viagra should be taken as needed about 1 hour before sexual activity. Sometime Generic Viagra can be taken anytime from 4 hours to 30 minutes before sexual activity.
Drug Class: Generic Viagra is a phosphodiesterase inhibitor. It works by helping the blood flow into the penis to achieve and maintain an erection.

Dosage: Generic Viagra is used as needed, so you are not likely to miss a dose. If you miss a dose of Generic Viagra, take the missed dose as soon as you remember. Do not take extra medicine to make up the missed dose.

Side Effects: If you experience any of the following serious side effects, stop taking Generic Viagra and seek emergency medical attention or notify your doctor immediately:

an allergic reaction
swelling of the ankles or legs
shortness of breath
prolonged or severe dizziness
a prolonged or painful erection
dizziness
nausea
angina

Other, less serious side effects may be more likely to occur. Continue to take Generic Viagra and talk to your doctor if you experience. Side effects other than those listed here may also occur:

flushing
mild dizziness
headache
nasal congestion
diarrhea
temporary blue tint in vision or other vision abnormalities
itching or a rash

Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

Description of Erectile Dysfunction Syndrome: The normal physiology of erection involves a complex series of events. The male penis contains 2 cylinders of sponge a like structure that run along its shaft, transversal to the urethra. When male sexual arousal occurs at any time, blood flows into this tissue with more density. As the tissue fills with the extra blood, it stiffens to create an erection. A male erection is kept by continued increased blood flow to this section. Once ejaculation occurs, or after sexual excitation stops, the blood flow decreases, and the sponge-like tissue empties and softens to the non-erect state. The nervous system responds to arousal by releasing chemicals, such as nitric oxide, into the penile blood to cause the blood vessels that carry blood to the penis to enlarge, increasing blood flow to the sponge-like cylinders, and forming an erection. Any interruption along this pathway may result in erectile dysfunction Syndrome

Risks and Factors: Erectile dysfunction Syndrome can be caused by psychological or physical factors. This is commonly due to anxiety, stress, depression, excess fatigue or dissatisfaction with the relationship with the partner. Physical causes can include any disorder that prevents the nervous system or vascular system from responding appropriately to arousal. Hormonal problems, kidney disease, liver disease, excessive alcohol ingestion, and infections can also cause EDS.