Opioids for musculoskeletal pain and their associations with reproductive and sexual function in women: an epidemiological study

Background One fifth of primary care attendees report chronic non cancer pain (CNCP) most of which is related to musculoskeletal conditions, 12% of these are prescribed strong opioid analgesics. Evidence suggests long-term opioid use causes hypogonadism in men (including sexual reproductive dysfunction), but in women, the relationship is not known. Aim To investigate the relationship between opioid use and reproductive and sexual dysfunction in women aged 18-55 years old. Methods A systematic review summarised existing evidence for sexual and reproductive dysfunction in women prescribed opioids (>1 month) for CNCP. Two further original studies investigated women prescribed opioids for musculoskeletal pain. A clinical practice research datalink (a UK primary care database) cohort study compared the risk of four outcomes (irregular/absent menstrual cycles, menopausal symptoms, low libido and infertility) for long-term (>/3 months) and short-term opioid users. A crosssectional study investigated the risk of female sexual dysfunction (FSD) dependent on daily oral morphine equivalent dose (MED). Results The systematic review identified 12 small papers, mainly from secondary care. Opioid use was associated with irregular menstruation, decreased libido and decreased sex hormone levels. In the cohort study (n=44260) there was an increased risk of abnormal menstruation (Hazard ratio (HR) 1.13; 95% CI 1.05, 1.21) and menopause (HR 1.16; 95% CI 1.10, 1.23) in long-term opioid users when compared to short-term users, but no association with infertility or low libido. The cross-sectional survey (n=153) found FSD in 50% of those receiving >/20mg MED daily, falling to 31.7% in those not currently using opioids (OR 2.29; 95% CI 0.94, 5.55). Conclusion This thesis highlights that there is an increased risk of menstrual disturbances and menopausal symptoms with opioids and these should be considered when opioids are prescribed for CNCP. These findings may help management decisions in CNCP when discussing treatment options with patients