How and when to take sildenafil It’s important to take sildenafil as advised by a doctor or pharmacist. Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient. The best time to take sildenafil is about 1 hour before sexual activity, but you can take the medication any time from 4 hours to 30 minutes before sexual activity. Small case studies in pregnant women with PAH indicate a low risk of harm, though caution is warranted. Furthermore, sildenafil use requires caution in patients with anatomical deformation of the penis and patients with conditions potentially predisposing them to priapism, such as sickle cell anemia or multiple myeloma.AdIt’s super shopping time. Don’t miss out. It’s super shopping time. Don’t miss out on special Black Friday offer!Brands: Dick’s Sporting Goods, Bass Pro, Kohl’s, Macy’s. Cost: If the price for branded Viagra is outside of your budget, Lemonaid’s $2 sildenafil pills are some of the lowest priced Viagra alternatives that we’ve found. Product details Usage: take. SILDENAFIL/Viagra (sil DEN a fil) treats erectile dysfunction (ED). It works by increasing blood flow to the penis, which helps to maintain an erection. Use this coupon to get this price at any WALGREENS Pharmacy location. Expand to see all locations within your area. Get Coupon. Add to Pricing Basket. E Macon St. E Macon St.