Fildena 50 mg may cause dizziness or blurring of vision depending upon certain situations. Viagra 50mg Tablet may be taken on an empty stomach or with a meal. It should be strictly taken as advised by your doctor. You should take about 1 hour before you plan to have sex. This medicine is not intended for use by women and men should avoid using any other medicines to treat impotence without talking to a doctor first. It can be dangerous to take it along with medicines called nitrates (often given for chest pain or angina).