Secondary adrenal insufficiency and pituitary dysfunction in oral/transdermal opioid users with non-cancer pain

Objective: To evaluate pituitary function, sexual function and quality of life (QoL) in patients on oral or transdermal opioids. Design and methods: Cross-sectional study comparing pituitary function, QoL and sexual function in people on long-term opioid therapy (n=40) vs an age- and sex-matched control group (n=25). Baseline pituitary function was assessed on blood samples collected prior to 0900h. Further testing with corticotropin (250µg IV) and metyrapone (30mg/kg) stimulation tests was undertaken on participants with serum cortisol 200mg and 0% with MEDD <60mg had SAI. Among male participants, testosterone was inversely associated with BMI (P=0.001) but not opioid use. A non-significant trend to low testosterone <8nmol/L in male opioid users (11/24 opioid users vs 2/14 control, P=0.08) suggests a small subgroup with opioid-induced androgen deficiency. Opioid users had greater fatigue, reduced quality of life in all subsections of the SF-36 and impaired sexual function in both males and females (all scores P<0.001 compared to controls). Conclusion: Long-term opioid therapy was associated with dose-related SAI in over 20% of chronic pain patients and is associated with poor quality of life, fatigue and sexual dysfunction. Obesity confounds the interpretation of opioid-induced male androgen deficiency.