Intrathecal opiods (eg, morphine) are frequently delivered by a subcutaneous pump into the spinal canal. This can relieve intractable back pain. A side effect of this treatment is suppression of anterior pituitary function, causing hypogonadotropic hypogonadism in all women (low estrogen & cessation of menstrual periods) and 86% of men (low testosterone); 15% of patients also develop hypocortisolism; 15% develop low growth hormone (GH). This was first published in JCEM 6/2000. Symptoms of hypogonadism, hypocortisolism, or GH deficiency can be remedied by replacement of the deficient hormone(s).