Wednesday, February 9, 2022
It is quite short-acting and lasts about 4 hours. However, in some men, its effects may last as long as 10 hours. (3)
Sildenafil is an effective drug for Erectile Dysfunction (ED) and starts to work as quickly as 12 minutes in some men, with a large proportion feeling the effects by 30 minutes, and the majority by 45 minutes. (1) By 24 hours the medication is at very low or undetectable levels in the body.
Vardenafil has a similar ‘half-life’ to Sildenafil of 4-5 hours. The half-life is the time it takes for the concentration of the drug to fall to half its original level. Once this happens, the drug will not be as effective as before. Tadalafil has a long half-life of 17.5 hours (2) and can be effective up to 36 hours.
Sildenafil has been licensed to treat ED since 1998. There are many years of safety data that have proved it safe and effective. Overall, its side effects are minor, such as headaches, nausea and dizziness.
Most men who are experiencing Erectile Dysfunction should be able to take Sildenafil.
Before 2013 the use of Sildenafil was restricted. It was only prescribed in its branded form ‘Viagra’ which was expensive and reserved for men with specific medical conditions. When new and cheaper unbranded versions became available, it was decided that the benefits it provided should be made available to the greater population.
This is because Sildenafil is not suitable for everyone. Men with low blood pressure, advanced liver disease, or who have recently suffered a heart attack or stroke should not take it. Nor should men who are taking medication that contains nitrates or those that have a rare eye disease known as retinitis pigmentosa.
As most men will feel its effects around 45 minutes, around 45 minutes to an hour before sexual activity is ideal. You might come across recommendations to take it 2 hours after a meal, however, studies have shown that taking it shortly before or with a meal does not influence its effectiveness (3). The erections produced by Sildenafil are not spontaneous and require a sexual stimulus.
Sildenafil is a PDE5 inhibitor. It works by stopping the breakdown of tiny molecules in cells that are involved in signalling pathways that increase blood flow to the penis. It’s usual to start at a dose of 50mg and titrate up the dose as needed depending on the effects.
The most common side effects include:
Rare side effects include allergic reactions and priapism (an erection lasting more than 4hrs) Both of these require urgent medical attention. It’s important to fully read the information leaflet to be aware of the rarer side effects.