Endocrine Abstracts

Background: Long-term opioid medication can cause opioid-induced adrenal insufficiency (OIAI), which is an underdiagnosed side effect that arises from the hypothalamic–pituitary–adrenal (HPA) axis being suppressed. Delays in diagnosis and treatment might result from clinical symptoms that are frequently ambiguous and may overlap with other chronic illnesses.

Case: A 54-year-old man was referred for an endocrine evaluation of progressive symptoms of fatigue, low mood, and recurrent falls over six months and abnormal hormonal tests. He had a medical history of testicular cancer, seizures, asthma. He had been treating his chronic cancer pain with tramadol and morphine for a long time. Upon examination, there were no obvious neurological abnormalities, but there was fatigue, proximal limb weakness, and an unusual stride.

Investigations: Serum testosterone was low (0.6 nmol/l) and morning cortisol was borderline (62 nmol/l) according to the first GP blood tests. Later testing revealed low ACTH levels (<4 ng/l) and a poor cortisol response to the Short Syn-acthen test (baseline 62 nmol/l, 30 min 381 nmol/l, 60 min 495 nmol/l), which is consistent with secondary adrenal insufficiency. The pituitary and brain MRIs showed no structural abnormalities. Renal and liver function, and electrolytes were within normal limits.

Results: The results were in line with opioid-induced secondary hypogonadism and adrenal insufficiency in the setting of long-term opioid medication. The patient was sent to endocrinology for further care, which included reviewing the opioid dosage and replacing the steroids.

Conclusion: This particular case illustrates the significance of considering OIAI when patients on long-term opioid treatment experience unexplained fatigue, weakness, and mood changes. It is essential to understand how opioids depress the HPA axis in order to ensure early diagnosis and appropriate management to prevent avoidable morbidity.

Keywords: opioid-induced adrenal insufficiency, secondary adrenal suppression, morphine, hypogonadism, chronic opioid therapy.