When do you take sildenafil
- have been told not to have sex, not to engage in sexual activity /actions that widen your blood vessels;
- have low blood pressure (hypotension);
- have had a stroke lately;
- have unstable angina;
- have had a heart attack; or
- have a history of non-arteritic anterior ischaemic optic neuropathy (this condition causes a sudden loss of vision).
side effects of pde-5 inhibitors include:.. .