Viagra (sildenafil) is prescribed to men in spite of their age to treat a condition commonly known as male impotence. A more scientifically correct name for it is, however, erectile dysfunction that reflects the very nature of the condition – inability to get an erection or hold it for long enough. Your doctor needs to know about any of the health conditions you have or used to have as some of them may require a dose adjustment. Viagra will not cure your erectile dysfunction of protect you from any sexually transmitted diseases, which means you are still required to use a condom. Viagra is a treatment for erectile dysfunction that needs to be taken every time you are going to have sex unless otherwise recommended by your health care provider. If you are taking any drugs or are planning on doing so, your health care provider needs to know that you are taking Viagra. You should be careful with taking any of the following medications and combining them with Viagra: anticoagulants, efavirenz, rifampin, high blood pressure medications, rifabutin, other erectile dysfunction treatment drugs, antifungals, beta blockers, HIV protease inhibitors, erythromycin, seizure medications, barbiturates, amlodipine, alpha blockers, cimetidine and some other ones. If you ever had a sudden loss of vision, priapism or retinitis pigmentosa you may not be able to take Viagra because the probability of certain serious side effects. Your doctor will provide you with any additional details you need to know.