Most men find that they tolerate sildenafil well, but as all medicines, sildenafil may cause side effects.
Common side effects of sildenafil include feeling dizzy or light-headed. These side effects can be made worse if you drink alcohol or take other certain medicines at the same time as the drug. Hot weather, taking exercise, or having a high temperature (fever) may also exacerbate these side effects while taking sildenafil.
If you do experience these side effects, you must let your doctor know and stop taking the medication. It is advisable not to drive or undertake potentially dangerous tasks such as operating heavy machinery.
Sildenafil can rarely cause severe side effects which include allergic reactions, vision disturbances and hearing problems.
Which side effects are common?
Common side effects of sildenafil include:
- visual disturbance and colour distortion
- facial flushing
- nasal congestion
Common side effects occur in around 1 in 100 people taking the medication.
Which less common side effects are there?
Uncommon side effects of sildenafil include:
- runny nose
- disturbance in sleep
- eye pain, and photophobia
- tinnitus, vertigo
- changes in blood pressure levels
- nose bleeds
- upper abdominal pain
- dry mouth
- muscle pain
- feeling hot or tired
Uncommon side effects affect between 1 in every 100 and 1 in every 1000 people taking sildenafil.
Can taking sildenafil have long term effects?
The European Association of Urology report that the long term use of PDE5 inhibitors (which is a type of drug that sildenafil belongs to) is well tolerated and effective. However, you should let your doctor know if you take an ED medication and have regular check ups if you use it over a long period of time.
Can sildenafil cause a heart attack?
Sildenafil’s manufacturer says that according to clinical trials there is no evidence that the drug causes heart attack or stroke. A study of 9000 men taking sildenafil, conducted by the Drug Safety Research Unit in Southampton and the University of Portsmouth, concluded that the drug did not cause heart attacks. Researchers found that men taking sildenafil were no more likely to suffer from a cardiac arrest or fatal heart problem than males in the general population.
Sildenafil is however not recommended for men with certain heart or circulation problems or those with severe pulmonary arterial hypertension.
Is it true that sildenafil causes blindness?
Sildenafil has been reported to cause temporary vision problems in men taking the drug. This is a very rare side effect, which means that it affects between 1 in 1000 and 1 in 10,000 people taking sildenafil.
When to see a doctor
Although many men can take Sildenafil and experience mild side effects or none at all, severe side effects can occur rarely. If you experience any of the following side effects while you’re taking sildenafil, you must get medical help straight away.
Severe side effects of sildenafil include severe allergic reactions (rashes; itching; hives; swelling of the mouth, face, lips or tongue; breathing difficulties; chest tightness). Other severe side effects include fast or irregular heartbeat; shortness of breath; burning sensations; chest pain; mental confusion; memory loss; passing out; tingling or numbness in arms or legs; a feeling of weakness on one side; seizure; persistent dizziness; severe or persistent nosebleeds; vision changes or loss of vision; problems speaking; hearing impairment or loss.
Sildenafil can also cause a painful erection that lasts for longer than four hours. This is known as priapism. If you experience any of these side effects, see a doctor immediately.
Avoiding side effects - What you can do
Taking sildenafil without seeking medical advice from a trusted source can be very dangerous and may result in potentially serious harm to your health. To ensure that you are taking sildenafil safely and to reduce the chance of experiencing unwanted side effects you must ensure that you obtain a prescription for the drug. Make sure that you take the correct dosage recommended to you.
If you experience any side effects you may need to reduce the dosage or stop taking sildenafil. Avoid alcohol and taking strenuous exercise while taking sildenafil. Certain medications, including those containing nitrates, can cause the possible side effects of sildenafil to be worse. Tell your doctor about any existing health conditions and any other medications you are taking before getting a prescription for sildenafil.