Common side effects of sildenafil can happen in more than one in 100 people, but taking too much can also cause unpleasant side effects. Some more serious reactions should be immediately flagged with a health professional.
Sildenafil is considered a relatively safe drug, which is why it is available without prescription.
Nonetheless, it is not a good idea to take too much.
Dr Douglas Savage, a GP specialising in sexual medicine, and senior medical consultant at the Centre for Men’s Health, spoke to Patient Info about what might happen if you exceed the recommended dose.
“I certainly wouldn’t advise it,” he said. He added that you would not end up with a permanent erection, “more likely a very bad headache.”
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Erectile dysfunction drugs should never be taken with recreational drugs, the site adds.
As well as headaches, the NHS states that taking too much sildenafil could cause dizziness, indigestion, a blocked nose and altered vision.
“Talk to your doctor if you have taken too much sildenafil and you’re worried about these side effects,” the healthy body recommends.
There are also some potentially more serious side effects of taking the drug.
Serious side effects are rare and happen in less than one in 1,000 people, state the NHS.
Stop taking sildenafil and call a doctor straight away if you get chest pains, prolonged and sometimes painful erections for more than four hours, or a sudden decrease or loss of vision.
Very serious side effects also include a serious skin reaction, symptoms of which “may include fever, severe peeling and swelling of the skin, blistering of the mouth, genitals and around the eyes,” the NHS states.
The drug can also cause seizures, and immediate medical help should be sought for this.
According to the National Institutes of Health (NIH), the drug, available as a tablet or liquid form, should be taken anywhere from four hours to 30 minutes prior to sexual activity.
Sildenafil should usually not be taken more than once every 24 hours, the NIH advises.
To get the most benefit from sildenafil, do not drink heavily before taking it.
“A beer or a couple of glasses of wine are not likely to stop or delay sildenafil working. But drinking lots of alcohol can make it more difficult to get an erection,” the NHS states.
Do not drink grapefruit juice if you’re taking sildenafil for pulmonary hypertension as it interferes with the way the medicine works.
You can eat and drink normally while taking sildenafil to get an erection.
Erectile dysfunction can often be improved for some people if you make changes to your lifestyle, such as quitting smoking and not taking recreational drugs.
Nonetheless, most men occasionally fail to get or keep an erection, according to the NHS.