LHRH agonists. A nonsurgical treatment for benign prostatic hyperplasia.

Luteinizing hormone-releasing hormone (LHRH) agonist, when administered in a continuous, nonpulsatile manner, causes desensitization of the LHRH receptor complex on the gonadotroph cells in the anterior pituitary gland. Biosynthesis and secretion of luteinizing hormone cease, and testicular androgenic production is inhibited. When used in this capacity, LHRH agonists can be an effective treatment for benign prostatic hyperplasia. After 4 to 6 months of therapy, prostatic volume decreases by 25% to 30%, voiding symptoms improve significantly in approximately 25% to 33% of patients, and the peak urinary flow rate increases substantially (more than 15 ml/second) in approximately 25% to 33% of patients. During the first month of treatment, serum luteinizing hormone, follicle-stimulating hormone, testosterone, dihydrotestosterone, 17 beta-estradiol, and prostate-specific antigen decline to low values and remain low throughout treatment. Prostatic 5 alpha-reductase activity and androgen receptor content also decrease with treatment. Side effects are significant: impotence, decreased libido, and hot flushes are the most common. Because the effect of LHRH agonist therapy on the serum testosterone concentration is reversible, treatment of benign prostatic hyperplasia with an LHRH agonist must be considered life-long therapy. Thus, this therapy should be reserved for patients who are impotent or who are poor surgical risks.