Take all of the tablets for your daily dose at one time each day; do not divide the tablets to take as separate doses. Soon, in , ICOS received a patent for compound IC structurally unlike sildenafil and vardenafil , and Phase 1 clinical trials began in Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Can Cialis be used with other treatments for impotence? A small number of patients taking Cialis also reported abnormal vision. Physicians should discuss with patients the potential for CIALIS to augment the blood-pressure-lowering effect of alpha-blockers and antihypertensive medications. However, because sexual stimulation is required to initiate the local penile release of nitric oxide, tadalafil’s inhibition of PDE5 will have no effect without sexual stimulation.Dosage for ED. • as needed dosage: 10 mg at least 30 minutes before sexual activity, with a maximum of one dose per day †. • daily dosage: mg once daily. • as .  · Cialis tablets come in four strengths: milligrams (mg), 5 mg, 10 mg, and 20 mg. What are the typical dosages of Cialis? Typically, your doctor will start you on a low . Tadalafil (Cialis) is a medicine used to treat erectile dysfunction (ED, also called impotence) and problems with urination caused by an enlarged prostate (benign prostatic hypertrophy or BPH). Tadalafil works by helping to relax the blood vessels in the penis, allowing blood to flow into the penis, and causing an erection.