These include itraconazole Sporanox, Tolsura , ketoconazole Extina, Ketozole, others and ritonavir Norvir. If you are taking sildenafil for erectile dysfunction, your doctor will probably start you on an average dose of sildenafil and increase or decrease your dose depending on your response to the medication. WATCH Ontario pharmacists can now treat 19 common ailments: Ontarians can now visit a pharmacist to treat 6 more common ailments 1 month ago Duration Featured VideoHealth Minister Sylvia Jones says Ontario has added six more common ailments to the list of conditions pharmacists can diagnose and treat, effective immediately, bringing the total to A newer form of the medicine that dissolves on the tongue might work faster than the pill that you swallow. Take sildenafil as needed before sexual activity.They’re often the first line of treatment for trouble getting or keeping an erection, called erectile dysfunction (ED). Oral medicines for ED usually work well and . Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Sildenafil (Liqrev, Revatio) is used to improve the ability to exercise in . Cost Overdose Ask your doctor Q&A Drug Images What is Viagra? If you have erectile dysfunction (ED), your doctor may recommend that you take Viagra. It’s a .