Keele Research Repository

BACKGROUND: One fifth of primary care attendees suffer chronic non-cancer pain, with musculoskeletal conditions the leading cause. 12% of patients with chronic non-cancer pain are prescribed strong opioids. Evidence suggests long-term opioid use is related to hypogonadism in men, but the relationship in women is unclear. Our aim was to investigate reproductive dysfunction in women prescribed long-term opioids for musculoskeletal pain. METHODS: We undertook a matched (matched 1:1; for year of birth, year of start of follow-up and practice) cohort study of women aged 18-55 years old, with musculoskeletal pain and an opioid prescription in the Clinical Practice Research Datalink (a primary care database) between 2002 and 2013. Long-term opioid users (≥90 days) were compared to short-term opioid users (<90 days) for four reproductive conditions (abnormal menstruation, low libido, infertility and menopause) using cox proportional hazards models. RESULTS: 44,260 women were included; the median cohort age at baseline was 43 years (Interquartile Range 36-49). Long-term opioid use was associated with an increased risk of altered menstruation (Hazard Ratio 1.13 95% CI 1.05 - 1.21); and with an increased risk of menopause (Hazard Ratio 1.16 95% CI 1.10 - 1.23). No significant association was found for libido (Hazard Ratio 1.19 95% CI 0.96 - 1.48) or infertility (Hazard Ratio 0.82 95% CI 0.64 - 1.06). CONCLUSIONS: The risk of menopause and abnormal menstruation was increased in long-term opioid users. This has implications for clinicians as reproductive dysfunction will need to be considered when prescribing long-term opioids to women with musculoskeletal conditions. This article is protected by copyright. All rights reserved.