Sildenafil

Sildenafil works by blocking the PDE5 enzyme, which allows levels of a substance called cyclic guanosine monophosphate (cGMP) to rise in the tissues of the penis. This helps relax the blood vessels and improve blood flow when a man is sexually stimulated. Sexual arousal is still needed for the medicine to take effect; it does not cause an erection on its own. It generally begins to work within roughly half an hour to an hour and its effect usually lasts for a few hours.

Sildenafil is normally taken by mouth a short time before planned sexual activity, at the dose advised by your doctor. It can be taken with or without food, although a heavy or high-fat meal may delay how quickly it starts to work. As a general rule no more than one dose should be taken in any 24-hour period. Always follow the instructions in the patient information leaflet and the advice of your doctor or pharmacist.

Common (usually mild and temporary):

• Headache
• Flushing of the face
• Indigestion or stomach upset
• Nasal congestion (blocked or runny nose)
• Dizziness
• Changes in vision such as a blue tinge or blurring

• Must NOT be taken with nitrate medicines (used for chest pain/angina) or nitric-oxide donors such as amyl nitrite 'poppers', as this can cause a dangerous drop in blood pressure.
• Use with caution if you have heart or blood-vessel disease, or if sexual activity has been advised against for heart reasons.
• Tell your doctor about any liver or kidney problems, as a dose adjustment may be needed.
• Caution is needed if you have low blood pressure or take alpha-blockers or other blood-pressure-lowering medicines.
• Drinking alcohol can lower blood pressure further and may reduce the medicine's effectiveness.
• Grapefruit and grapefruit juice may affect how the medicine works and are best avoided.
• Not intended for use by women, children or anyone under 18 years of age.

Store in the original packaging below 30°C, out of the sight and reach of children, and do not use after the expiry date.