More about Viagra
What is VIAGRA?
Viagra belongs to a group of medicines called phosphodiesterase type 5 inhibitors.
It is blue, diamond shaped, oral tablet prescribed to treat men suffering from clinical erectile dysfunction.
It is not an aphrodisiac and does not increase libido.

How does Viagra work?
Viagra works by helping to relax the blood vessels in the penis, allowing blood to flow into the penis causing an erection. However, it will only help a man to get an erection if he is sexually stimulated. It should not be taken by men who do not have erectile dysfunction.

How do you take Viagra?
Viagra is available in three strengths, 25 mg, 50 mg and 100 mg. The initial dose is selected by your doctor. Viagra should be swallowed whole with some water about an hour before anticipated sexual activity. The amount of time it takes to work varies from person to person, on average it takes between 20 minutes to one hour. Within a 1 to 6 hour period after taking the tablet an erection should occur in response to sexual stimulation. A man may find that Viagra takes longer to work if taken with a heavy meal. Alcohol consumption can temporarily interfere with the erection process. To get the maximum benefit from the medication it is advisable not to drink large amounts of alcohol before taking Viagra. Viagra should not be used more than once a day. Viagra should be taken only as directed by your doctor, who will take into account any other medications you may be taking.

What side affects may be associated with Viagra?
The manufacturers have tested the drug on nearly 4,000 men during 21 clinical trials. When taken at the recommended doses some side effects have been reported although they were generally mild to moderate and brief in length. The most common side effects are headache and facial flushing. Less commonly reported are indigestion, dizziness, stuffy nose and effects on vision (predominantly a blue colour tinge to vision and increased brightness of light or blurred vision).

Who cannot take Viagra?
Any man who has been informed by his doctor that he is not fit enough to resume sexual activity. Patients who are taking any nitrate medications Nitrate medicines are commonly prescribed for relief of angina pectoris "chest pain". In combination with Viagra, they could seriously lower blood pressure. Patients should inform their Doctor if they are taking any of these medicines or ask if they are not certain.

VIAGRA and Poppers
Some people use non-prescribed nitrates socially or sexually.
VIAGRA must not be combined with nitrite inhalants ("poppers") or any form of nitrates, because the combination may result in dangerously low blood pressure, which could be fatal.

Viagra (sidenafil) and Protease Inhibitors
Viagra doses must be low when it is used with HIV protease inhibitors (especially ritonavir), because these antivirals reduce the metabolism of sildenafil in the liver, resulting in abnormally high blood levels that can cause adverse effects. The combination apparently does not affect blood levels of protease inhibitors. It has been recommended that a single does 25 mg of sildenafil in a 48 hour period should not be exceeded in patients receiving HIV protease inhibitors