After orchiectomy (castration), about 90% of men have reduced or absent libido (sexual desire) and ED. Over half of men have hot flashes (sudden rushes of body heat) after surgery, but these may go away with time.
Side effects of luteinizing hormone-releasing hormone (LH–RH) agonists are the same as with an orchiectomy and include reduced or absent sexual desire, ED, and hot flashes. Some men also have breast tenderness and growth of breast tissue (called gynecomastia). Breast growth usually occurs in men who take estrogen therapy. Using LH–RH agonists over a long period of time can also cause osteoporosis (weakening of bones), fatigue, muscle wasting, and change in fat distribution. These side effects occur about as commonly as after orchiectomy.
A possible short-term side effect of LH–RH agonists is what is known as tumor flare. When first given, these medicines can cause a temporary rise in testosterone levels, which can cause pain at tumor sites, especially if the cancer has already spread to bone. To prevent this, a short course of anti-androgens (at least 7 days) may be given when the LH–RH agonist is first started.
Side effects of anti-androgens in patients already treated by orchiectomy or with LH–RH agonists are usually not serious or common, but may include nausea, diarrhea, tiredness, liver disease, and the growth of breast tissue, especially with prolonged use.
