Viagra general information

What is Viagra used for?

Viagra 100mg tablets are used to treat erectile dysfunction (impotence) in men, which is inability to achieve or maintain a hard erect penis suitable for sexual activity, due to insufficient blood flow into the penis. Viagra 100mg tablets relax the blood vessels in the penis increasing blood flow and causing an erection, which is the natural response to sexual stimulation. However, Viagra 100mg tablets will only work if you are sexually aroused. 

How does Viagra work?

Viagra 100mg tablets contain sildenafil which acts on the erectile tissue of the penis to increase blood flow which causes an erection. During sexual stimulation nitric oxide is released in the erectile tissue of the penis which activates the enzyme guanylate cyclase. This enzyme increases levels of a chemical called cyclic guanosine monophosphate (cGMP), which relaxes the blood vessels in the penis and allows blood to fill the spongy erectile tissues to cause an erection. Another enzyme called phosphodiesterase type 5 (PDE5) breaks down cGMP preventing blood flow into the penis, which causes loss of an erection. Viagra 100mg tablets inhibit the action of PDE5 which resolves erectile dysfunction by allowing the natural process of sexual stimulation to activate the cGMP mechanism for achieving and maintaining an erection. 

How long does Viagra last?

Viagra 100mg tablets should be taken within an hour of planned sex and in most cases it helps you to get an erection in about 30 minutes that will last for around 4 hours, provided you are sexually excited. Viagra 100mg tablets do not work if you are not aroused. 

What does Viagra contain?

Viagra 100mg tablets contain the active ingredient sildenafil which resolves erectile dysfunction (impotence) in men, by increasing blood flow into the penis. Viagra 100mg tablets also contain microcrystalline cellulose, calcium hydrogen phosphate (anhydrous), croscarmellose sodium, magnesium stearate, hypromellose, titanium dioxide (E171), lactose, triacetin, indigo carmine aluminium lake (E132). 

Treating erectile dysfunction (impotence) with Viagra

Viagra 100mg tablets contain sildenafil, a phosphodiesterase type 5 (PDE5) inhibitor, used to treat erectile dysfunction in men (impotence). When taken before planned sexual activity, Viagra 100mg tablets inhibit the breakdown (by the enzyme PDE5) of a chemical called cGMP, produced in the erectile tissue of the penis during sexual arousal, and this action allows blood flow into the penis causing an erection. 

What are the side effects of Viagra?

Viagra 100mg tablet are generally well tolerated but it is always possible that you may experience side effects. The more common side effects include: headache, dizziness, flushing, indigestion, nasal congestion, diarrhoea, rash. More serious side effects include unusual heart beat, urinary tract infection (stinging or burning urine, more frequent need to pass urine), blood in the urine, changes in vision such as blurring, a blue colour to your vision or a greater awareness of light, persistent headache or fainting, bleeding from the nose. 

When should Viagra not be used?

You should not use Viagra if you:

• are taking any nitrate medication, such as nitroglycerin for angina, as it may lead to a severe drop in blood pressure
• have a condition where sexual intercourse inadvisable due to cardiovascular or heart problems or you have had a heart attack or stroke in the last 6 months
• have liver disease
• have abnormally high or low blood pressure
• have an eye disease like non-arteritic anterior ischaemic optic neuropathy (NAION), which causes loss of vision or if you have retinitis pigmentosa
• are allergic to sildenafil or any other ingredients in Viagra 100mg tablets
• are taking medication that may interact with Viagra or may increase your risk for side-effects, including cimetidine for treating ulcers, antibiotics like erythromycin and rifampicin, verapamil or diltiazem (for high blood pressure), ritonavir or saquinavir (for HIV), itraconazole or ketaconazole (for fungal infections) alpha-blockers; like amlodipine for high blood pressure

How should Viagra be taken?

You should take one Viagra 100mg tablet with a glass of water approximately one hour before sexual activity and without food. If you have a large meal before taking your Viagra 100mg tablet it may take longer to work. You should take no more than one tablet a day and only if you plan to have sex. 

Missed dose of Viagra

You should only take a Viagra 100mg tablet when you plan to have sex; it is not intended as a regular medication. 

How should Viagra be stored?

You should keep your Viagra 100mg tablets in their blister pack until used and store in a cool, dry place where the temperature stays below 30°C.