Always discuss with your health care practitioner ALL of the medications you are taking prescription and over-the-counter that way, you can receive the best advice for your own situation. People taking nitrates like nitroglycerin Nitrostat or isosorbide mononitrate Imdur should not take PDE5 inhibitors, as doing so could result in a dangerous drop in blood pressure. More serious side effects may include a drop in blood pressure or an erection that lasts longer than four hours. Those with pre-existing conditions should always consult a healthcare provider before taking new medications or supplements. What if I am taking other drugs? 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. Finally, we checked customer reviews to better understand user experiences with each platform.Generic Cialis Tadalafil (Cialis) Switch to brand medication info_outlined Used for Benign Prostatic Hyperplasia and Erectile Dysfunction MORE expand_more Check your prescription Prescription 5mg tadalafil (Cialis) (30 tablets) edit Choose your pharmacy moses lake, WA Safeway Walgreens Rite Aid info How to use this coupon phone Need help? Drug details Here are some details about Cialis: Drug form: oral tablet Generic version: tadalafil Read on to learn about Cialis and cost, as well as how to save money on prescriptions and find. tadalafil. erectile dysfunction (ED) benign prostatic hyperplasia, or BPH). Tadalafil (Cialis) is available both as brand-name and generic tablets. Common side effects of this medication include headache and indigestion. Tadalafil (Cialis) does interact with some medications.