Viagra generally refers to sildenafil, and after the drug is used, the effect lasts for about 1-3 hours. And, the medication needs to be used regularly under the guidance of a doctor.
The drug needs to be taken by the patient about half an hour before intercourse. The effect of the drug lasts for about 1-3 hours and will not last for several days, so patients should not be too nervous.
The common adverse reactions of sildenafil are mainly headache, flushing, dizziness, nasal congestion, indigestion, and visual abnormalities. Rare adverse reactions mainly include facial edema, shock, weakness, pain, rash, tachycardia, palpitations, hypotension, postural hypotension and so on.
Sildenafil is prohibited in combination with nitrates, the drug is contraindicated in women, people who are allergic to the product, children, people whose recent cardiovascular state is not suitable for sexual intercourse.
Patients taking sildenafil should consult a doctor before using the drug, and take it under their guidance, do not take it blindly on their own.