Sex hormone suppression by intrathecal opioids: a prospective study

Clin J Pain. 2002 May-Jun;18(3):144-8. doi: 10.1097/00002508-200205000-00002.


Objective: Sexual dysfunction and low testosterone levels have been observed previously in males with chronic noncancer pain treated with intrathecal opioids. To investigate the hypothesis that intrathecal opioids suppress the hypothalamic-pituitary-gonadal axis, a prospective nonrandomized investigation of the function of this axis was undertaken.

Design: Ten males with chronic noncancer pain were evaluated for clinical and biochemical evidence of hypogonadism at baseline and during the first twelve weeks of intrathecal opioid therapy.

Results: Intrathecal opioid administration resulted in a significant (p <0.0001) reduction in serum testosterone, from 7.7 +/- 1.1 (mean +/- SEM) nmol/L at baseline to 2.0 +/- 0.7, 2.8 +/- 0.5, and 4.0 +/- 0.9 nmol/L at 1, 4, and 12 weeks, respectively. This was associated with a reduction in libido and potency. Luteinizing hormone and follicle-stimulating hormone levels remained within reference ranges, indicating central rather than peripheral suppression.

Conclusions: Administration of intrathecal opioids may result in hypogonadotrophic hypogonadism. As part of the consent for therapy process, patients should be informed about this effect and its management. With long-term intrathecal opioid administration, the hypothalamic-pituitary-gonadal axis should be monitored. Where indicated, testosterone replacement should be undertaken to improve sexual function and prevent the potential metabolic effects of hypogonadism, in particular, osteoporosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Chronic Disease
  • Genitalia, Male / drug effects
  • Gonadal Steroid Hormones / antagonists & inhibitors*
  • Humans
  • Hypothalamo-Hypophyseal System / drug effects
  • Injections, Spinal
  • Libido / drug effects
  • Male
  • Middle Aged
  • Narcotics / administration & dosage*
  • Narcotics / adverse effects*
  • Narcotics / therapeutic use
  • Pain / blood
  • Pain / drug therapy*
  • Prospective Studies
  • Testosterone / antagonists & inhibitors
  • Testosterone / blood


  • Gonadal Steroid Hormones
  • Narcotics
  • Testosterone