More serious side effects may include a drop in blood pressure or an erection that lasts longer than four hours. When taken at the correct time and paired with sexual stimulation, the erection lasts long enough for successful intercourse. Follow-up support: Make sure you can get the help you need if questions or concerns arise after ordering. What is tadalafil 20 mg used for? Medical consultations were also taken into consideration, as PDE5 inhibitors require a valid prescription from a licensed medical provider. Note that tadalafil in 20 mg tablets is the generic for brand-name drug Adcirca, which is used to treat pulmonary arterial hypertension.Prices for the generic, known as tadalafil, are more than 50% less than those of brand-name Cialis. As more men are able to afford tadalafil and treat their ED, . The cost for tadalafil oral tablet 5 mg is around $27 for a supply of 90 tablets, depending on the pharmacy you visit. Quoted prices are for cash-paying customers and are not valid . Drug details Here are some details about tadalafil: Learn more about the different dosages for Cialis here. Pros and cons at a glance Below are some advantages .