Do you use any illegal drugs? Lose excess pounds. There are two different ways to take tadalafil, either daily or on an as needed basis. If you drink a large amount of alcohol more than five glasses of wine or five shots of whiskey while you are taking tadalafil you are more likely to experience certain side effects of tadalafil such as dizziness, headache, fast heartbeat, and low blood pressure. Tadalafil may not be safe for people with certain medical conditions, including people who have had a stroke , have coronary heart disease or retinitis pigmentosa an eye disease. Take all of the tablets for your daily dose at one time each day; do not divide the tablets to take as separate doses.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. The most common side effects with Cialis are: headache, indigestion, back pain, muscle aches, flushing, and stuffy or runny nose. These side effects usually go away after a few hours. Men who get back pain and muscle aches usually get it 12 to 24 hours after taking Cialis. Back pain and muscle aches usually go away within 2 days.  · limiting or avoiding alcohol. managing any underlying health conditions, such as high blood pressure or diabetes. improving sleep habits. A lack of sexual desire can also influence ED in older.