In cases of benign prostatic hyperplasia, or BPH, there are two primary types of drugs used to relieve the symptoms. One class of medication, called 5 alpha-reductase inhibitors, decreases the size of the prostate by blocking an enzyme that acts on the male hormone, testosterone. When the enzyme is blocked, growth slows and, over time, the gland may shrink. Keep in mind that this treatment is most effective on larger prostate glands, and significant results may not be seen for six to 12 months.
A second class of medications used to treat BPH is alpha-adrenergic receptor blockers. These relax the smooth muscle of the prostate and bladder neck. For many men, alpha-blockers can relieve pressure, improve urine flow, and reduce symptoms within days. However, there are several possible side effects, including dizziness, headache, fatigue, and reduced blood pressure.