How does Viagra and Sildenafil work?
Viagra (Sildenafil) helps men to get and maintain an erection when sexually stimulated and/or excited. The medicine relaxes the blood vessels in the penis which results in more blood flowing to the penis when you are sexually excited.
How do I take it?
You should take Viagra (Sildenafil) approximately 1 hour before planning to have intercourse. Within a window of between 30 minutes and 4 hours after you take the medicine, it will be easier to keep and maintain an erection when you are sexually excited. If you take this medicine after a meal with a high fat content it may take a little longer to start working. This medicine will only work when you are sexually excited. You won’t get an erection just by taking Viagra (Sildenafil).
The standard recommended dose for Viagra (Sildenafil) is 50mg and this will be suitable for most people. If this dose is not effective, you can try 100mg and if 50mg gives you side effects you can also reduce the dose to 25mg tablets.
You must not take more than 100mg daily of Sildenafil/ Viagra. Clinical trials have been conducted in patients taking up to 200mg sildenafil and it was found that ‘doses of 200mg did not result in increased efficacy but did increase the incidence of adverse reactions (headache, flushing, dizziness, dyspepsia, nasal congestion, and altered vision).’
In addition, in patients taking more than 100mg daily, there have been reports of rhabdomyolysis (a breakdown in skeletal muscle tissue the byproducts of which can lead to kidney failure), visual perception changes, vertebral artery dissection (a tear in the artery supplying blood to the brain), heart attacks and aggressive behaviour.
If the 100mg strength doesn’t work for you, there may be alternatives you can try and we recommend that you call us for a free consultation with our pharmacist or doctor to discuss any underlying conditions you may have. We recommend that all men taking medicine for erectile dysfunction have regular tests for blood pressure, cholesterol, diabetes and hormone imbalances. For instance, it may be that by fixing a hormone imbalance such as testosterone, your Viagra medication will be even more effective.
In addition, drug manufacturers do not advise patients to split tablets in half to get the correct dosage as they cannot guarantee that the active ingredient will be distributed evenly throughout the tablet. For instance, if you cut a 100mg tablet in two, you may find that you get 80mg in one half of the tablet and 20mg in the other half leading to either an overdose (increased risk of side effects) or a suboptimal dose (the medication may not work).
It is important that you choose the correct dose for you. If you wish to talk to our pharmacist or doctor about this, please contact us in the pharmacy on 01625 460621 or email [email protected]
Viagra (Sildenafil) is normally well tolerated, however, side effects can include:
Side effects normally subside after a few hours, however, if you experience a prolonged or painful erection (longer than 4 hours), then you must contact your doctor immediately.
There are a number of medicines which interact with Sildenafil/ Viagra. For an exhaustive list please see the patient information leaflet (see section below) or call us in the pharmacy to discuss your specific situation. The main drug interactions are listed here:
Recreational drugs such as ‘poppers’ or amyl nitrate
Alpha blockers used for urinary retention or blood pressure problems (eg Flomax or Cardura)
Anti- arrhythmic drugs such as disopyramide
Antibiotics such as erythromycin
Antifungals such as itraconazole
Antivirals such as drugs used to treat HIV
Calcium channel blockers to treat blood pressure and angina such as amlodipine
Dapoxetine (Priligy – used to treat premature ejaculation)
Cimetidine (to treat stomach ulcers)
Please do not take Sildenafil/Viagra if you have taken any of the above drugs within the last 60 days without first consulting with either us in the Pharmacy ([email protected] / 01625 460621) or via email with our doctor [email protected]
**We advise not to take Sildenafil/Viagra with grapefruit juice as the blood concentration of Sildenafil will possibly be increased resulting in side effects.
Patient Information Leaflets
Please click here for the patient information leaflet for Viagra.
Storing Medicines Safely
Please keep your medicine out of the reach of children and store at room temperature. Unwanted medicine can be disposed of by returning it to any local pharmacy or indeed to us here for us to dispose of it for you.