What side effects can this medication cause? Your doctor will probably tell you not to take tadalafil if you are taking street drugs containing nitrates. You may attempt sexual activity at any time between doses. In trials of the drug, individuals taking Cialis saw a significant reduction in the frequency and urgency of urination and improved urine flow. Take tadalafil at around the same time every day.For the as-needed dose, plan to take Cialis at least 30 minutes before sexual activity, but bear in mind it may take as long as 2 hours to take effect. Also, Cialis requires sexual stimulation to. Compare prices and print coupons for Tadalafil (Adcirca) (Generic Adcirca) and other drugs at CVS, Walgreens, and other pharmacies. Get a free coupon or join GoodRx to save more. Local pharmacy prices Choose a pharmacy to get a coupon. 8 Essential Things to Know About Generic Cialis Written by Jennifer Gershman, PharmD, CPh, PACS. Tadalafil – STADA T20 – 20 Milligramm. Tadalafil, sold under the brand name Cialis among others, is a medication used to treat erectile dysfunction, benign prostatic hyperplasia, and pulmonary arterial hypertension. It is taken by mouth. Onset is typically within half an hour and the duration is up to 36 hours. Common side effects include headache, muscle pain, .