A 77-year-old woman with a history of anal squamous cell carcinoma was admitted because of malaise, diarrhea and nausea, in addition to back pain related to a verte-
bral compression fracture. During the course of treatment,

opioid therapy was initiated, following which the patient became progressively hypotensive and hyponatraemic and respiratory drive progressively decreased. Serum levels of cortisol, TSH and LH were decreased and prolactin slightly elevated, but a Synacthen test and brain MRI turned out normal, suggesting a diagnosis of opioid-induced pituitary dysfunction. The patient was given glucocorticoid replacement therapy with good results. Here we present a case of this serious but less well recognised side-effect of opioids.