Hitrin is used to treat high blood pressure (hypertension). High blood pressure adds to the work load of the heart and arteries. If it continues for a long time, the heart and arteries may not function properly. This can damage the blood vessels of the brain, heart, and kidneys, resulting in a stroke, heart failure, or kidney failure. High blood pressure may also increase the risk of heart attacks. These problems may be less likely to occur if blood pressure is controlled. Hitrin helps to lower blood pressure by relaxing blood vessels so that blood passes through them more easily. Hitrin is also used to treat benign enlargement of the prostate (benign prostatic hyperplasia [BPH]). Benign enlargement of the prostate is a problem that can occur in men as they get older. The prostate gland is located below the bladder. As the prostate gland enlarges, certain muscles in the gland may become tight and get in the way of the tube that drains urine from the bladder. This can cause problems in urinating, such as a need to urinate often, a weak stream when urinating, or a feeling of not being able to empty the bladder completely. Hitrin helps relax the muscles in the prostate and the opening of the bladder. This may help increase the flow of urine and/or decrease the symptoms. However, Hitrin will not help shrink the prostate. The prostate may continue to grow. This may cause the symptoms to become worse over time. Therefore, even though Hitrin may lessen the problems caused by enlarged prostate now, surgery still may be needed in the future.