Terazosin (TRZ)

Terazosin is a selective alpha 1 antagonist used for treatment of symptoms of an enlarged prostate (BPH). It also acts to lower the blood pressure, and is therefore a drug of choice for men with hypertension and prostate enlargement. It works by blocking the action of adrenaline on smooth muscle of the bladder and the blood vessel walls. Most common side effects include dizziness, drowsiness, headache, constipation, loss of appetite, fatigue, nasal congestion or dry eyes, but they generally go away after only a few days of use. Therapy should always be started with a low dose to avoid first dose phenomenon. Sexual side effects are rare, but may include priapism or erectile dysfunction. Terazosin however, differs from prazosin in that its water solubility is 25 times greater than that of prazosin and its elimination half-life is about three times that of prazosin.