Viagra (sildenafil citrate) is aimed at helping male patients using it to achieve harder erections as a result of intensified blood flow to the tissues of the penis. Make sure you take Viagra only if you have some problems that are caused by factors that cannot be eliminated. For example, in some cases erectile dysfunction may be caused by the fact you are taking some drugs you really need. Viagra is a prescription drug, but it can be purchased without one if you find the right online pharmacy and place an order there. This is very convenient, as you are always getting much lower prices, and still high quality. However, no matter how you purchase Viagra, you need to avoid combining it with certain medications you are taking. Such drugs as drugs to treat high blood pressure, antidepressants, heart or blood pressure medications, prostate disorder, antibiotics, imatinib, diclofenac, conivaptan, HIV/AIDS medicines, antifungal medications, isoniazid, or heart rhythm medicines must never be combined with Viagra before you have discussed everything with a qualified professional. This drug is never to be shared with other people to whom it was not recommended.