Follow your doctor’s orders or the directions on the label. Do not press on the plunger of the syringe. Beri tahu dokter riwayat alergi yang Anda miliki. In some patients, the use of VIAGRA with alpha-blockers can lead to a drop in blood pressure or to fainting medicines called HIV protease inhibitors, such as ritonavir Norvir , indinavir sulfate Crixivan , saquinavir Fortovase or Invirase , or atazanavir sulfate Reyataz some types of oral antifungal medicines, such as ketoconazole Nizoral and itraconazole Sporanox some types of antibiotics, such as clarithromycin Biaxin , telithromycin Ketek , or erythromycin other medicines that treat high blood pressure other medicines or treatments for ED VIAGRA contains sildenafil, which is the same medicine found in another drug called REVATIO. If you have severe ED, it might be increased to mg. Some people may also have ringing in their ears tinnitus or dizziness. For treatment of erectile dysfunction: For oral dosage form tablets : Adults up to 65 years of age—50 milligrams mg as a single dose no more than once a day, 1 hour before sexual intercourse.Find the best sildenafil citrate or viagra prices near you now with our cost comparison tool and start saving today. QTY 30 • MG • Tablet • Near EDIT; Add to Medicine Chest; Set Price Alert; More Ways to Save; SILDENAFIL/Viagra (sil DEN a fil) treats erectile dysfunction (ED). It works by increasing blood flow to the penis.  · This is the normal dose of Viagra that produces improvements for most men with ED. Depending on your needs, your dosage may be adjusted to 25 or mg. If you’re prone to side effects from Viagra, your healthcare provider may lower your dosage. If you have severe ED, it might be increased to mg. Side Effects. Dizziness, headache, flushing, or stomach upset may occur. Vision changes such as increased sensitivity to light, blurred vision, or trouble telling blue and green colors apart may.