Maximum observed plasma concentrations are reached within 30 to minutes median 60 minutes of oral dosing in the fasted state. This medicine is available on prescription and you can also buy it from most pharmacies. About sildenafil Viagra Sildenafil is a medicine used to treat erection problems erectile dysfunction. Data shared with Viatris will be aggregated and de-identified; it will be combined with data related to other Savings Offer redemptions and will not identify you Viatris reserves the right to rescind, revoke, or amend this Savings Offer without notice No membership fees. Is 20mg of Cialis better than mg of Viagra? In vivo studies: No significant interactions were shown with tolbutamide mg or warfarin 40 mg , both of which are metabolized by CYP2C9. Medicines that block an enzyme called CYP3A4.VIAGRA is supplied as blue, film-coated, rounded-diamond-shaped tablets containing sildenafil citrate equivalent to 25 mg, 50 mg, or mg of sildenafil. Tablets are debossed with PFIZER on one side and VGR25, VGR50 or VGR on the other to indicate the dosage strengths. Close. AdSave Time & Money with Online Prescription for Viagra, Cialis, Sildenafil and Tadafil. Free & Private Online Consultant with Real Doctors. Reliable E.D. Meds Shipped DiscreetlyK+ visitors in the past monthFree Shipping · Discreet Packaging · Real Doctors · Personalized PlanTypes: Sexual Health · Privacy Policy · Premature Ejaculation. Medically reviewed by Melissa Badowski, PharmD, MPH, FCCP — By Jennifer Mitri Williamson, Pharm.D. — Updated on September 12, Learn about .