Prevalence of Opioid-Induced Adrenal Insufficiency in Patients Taking Chronic Opioids.

CONTEXT: Chronic opioid use may lead to adrenal insufficiency because of central suppression of the hypothalamic-pituitary-adrenal axis. However, the prevalence of opioid-induced adrenal insufficiency (OIAI) is unclear.

OBJECTIVE

To determine the prevalence of OIAI and to identify predictors for the development of OIAI in patients taking opioids for chronic pain.

DESIGN

Cross-sectional study, 2016-2018.

SETTING

Referral center.

PATIENTS: Adult patients taking chronic opioids admitted to the Pain Rehabilitation Center.

MAIN OUTCOME MEASURE: Diagnosis of OIAI was considered if positive case detection (cortisol < 10 mcg/dL, ACTH < 15 pg/mL, and dehydroepiandrosterone sulfate < 25 mcg/dL), and confirmed after endocrine evaluation. Daily morphine milligram equivalent (MME) was calculated.

RESULTS

In 102 patients (median age, 53 years [range, 22-83], 67% women), median daily MME was 60 mg (3-840), and median opioid therapy duration was 60 months (3-360). Abnormal case detection testing was found in 11 (10.8%) patients, and diagnosis of OIAI was made in 9 (9%). Patients with OIAI were on a higher daily MME (median, 140 [20-392] mg vs 57 [3-840] mg, P = 0.1), and demonstrated a 4 times higher cumulative opioid exposure (median of 13,440 vs 3120 mg*months, P = 0.03). No patient taking <MME of 20 mg/day developed OIAI (sensitivity of 100% for MME > 20 mg); however, specificity of MME cutoff >20 mg was only 19%. After opioid discontinuation, 6/7 patients recovered adrenal function.

CONCLUSION

The prevalence of OIAI was 9%, with MME cumulative exposure being the only predictor for OIAI development. Patients on MME of 20 mg/day and above should be monitored for OIAI.