Sildenafil
Also sold as: Viagra
Prescription neededBladder, prostate and men's health
Comes as:Tablet
Usual adult dose
For erection problems: usually 50 mg about 1 hour before sex, not more than once a day; the doctor may change it to 25 or 100 mg. Never take it with nitrate heart medicines.
Your doctor may give you a different dose. Children's doses depend on weight.
Side effects
Common
- headache
- facial flushing
- indigestion
- blocked nose
- dizziness
- bluish vision
Serious — get help
Stop taking it and see a doctor straight away if you notice:
- chest pain
- erection lasting more than 4 hours
- sudden loss of vision or hearing
Do not take it, or take care, if
- Taking nitrate medicines (glyceryl trinitrate, isosorbide) — can cause a dangerous drop in blood pressure
- Recent heart attack or stroke, or very low blood pressure
- Serious heart disease where sex is not advised
- Severe liver disease
Interactions
Medicines that can react with this one.
Serious3 medicinesDo not take these together unless your doctor says so.
- Glyceryl trinitrate
Can cause a dangerous drop in blood pressure; never use together.
- Isosorbide dinitrate