Your primary care doctor should always know what medications you’re taking, including ED pills prescribed by another provider. These medicines are called PDE5 inhibitors. It’s available in 50 mg, mg, and mg tablets. Generic versions of sildenafil, vardenafil and tadalafil are available. Popular ED medications found online include: Viagra sildenafil : As the first FDA-approved PDE5 inhibitor for ED, sildenafil is taken 30 minutes to four hours before sexual intercourse to help achieve and maintain an erection.Medications Prescribed: Viagra, Cialis, Cialis Daily, Levitra, tadalafil, sildenafil, vardenafil. Generic offered: Yes. Why We Chose It. The simple combination of Rex MD’s online platform, its helpful customer service, and the abundance of ED treatment options make it a one-stop shop for all your sexual health needs. Vardenafil and tadalafil (Cialis) are both first-choice medications for treating ED. However, tadalafil (Cialis) can also be used to treat symptoms from an enlarged both medications can be used as needed for sexual activity (up to once a day), it’s possible for some people to take tadalafil (Cialis) daily on a regular basis . 3. Show coupon to your pharmacistPresent your printed or electronic coupon when you pick up your prescription. Vardenafil works best if it’s taken about an hour Missing: sale.