Endocrine Abstracts

Case history: A 39-year-old lady first presented to our endocrine outpatient clinic in September 2014 when blood tests at her GP surgery showed serum cortisol of 65 nmol/l. She had been having chronic back pain which is treated with Buprenorphine patches for many years. A Short Synacthen test (SST) showed an inadequate response. A low ACTH suggest secondary adrenal insufficiency. Other pituitary function tests and MRI of the pituitary were normal. After staying off buprenorphine patch for 3 months, a repeated SST showed an improved baseline cortisol with an adequate response to SST. The patient’s back pain recurred and she resorted to buprenorphine patches again which then precipitated another episode of secondary adrenal insufficiency. She was treated with steroids and low dose Fentanyl patch. Repeat SST after stopping buprenorphine patch showed an adequate cortisol response. She remained well when she was last seen in September 2017.

Investigations, results and treatment

September 2014

Na+140 mmol/l

K 4.3 mmol/l

T4 10.6 pmol/l

TSH 5.99 mIU/l

Serum cortisol of 65 nmol/l

SST: baseline corticol: 11 nmol/l; cortisol at 30 mins: 139 nmol/l; 60 mins: 183 nmol/l

Paired ACTH: 10 nmol/l

TREATMENT (September 2014): Stop buprenorphine patch and steroid replacement.

March 2015

SST: baseline cortisol: 123 nmol/l; 30 minutes: 438 nmol/l.

September 2015 (after restarting buprenorphine patch)

9 am baseline cortisol: 35 nmol/l.

Treatment(September 2015): Stop buprenorphine patch and steroid replacement.

Post stopping buprenorphine in Sept 2015:

SST: baseline cortisol of 226 nmol/l; 484 nmol/l at 30 minutes; 548 nmol/l at 60 minutes.

Conclusions and points for discussion: Opioid is a commonly prescribed medication for chronic pain. Long-term opioid medications have been shown to impair the hypothalamic-pituitary-adrenal (HPA) axis. There are only a few reported cases of secondary adrenal insufficiency (AI) from chronic opioid exposure. This is the first clinical case of secondary AI caused by chronic buprenorphine patch use. Buprenorphine is a partial agonist at mu opioid receptor. It has a long half-life of 24–60 hours. It is mainly used to treat opiates addiction and moderate chronic pain. Our case report showed that stopping long-acting opioid improved the function of HPA axis in a patient diagnosed with secondary AI. The recurrence of AI on drug rechallenge support buprenorphine patch as the cause of the event. Symptoms suggestive of AI in a patient on chronic opioid should instigate investigation of the HPA axis. There are no treatment guidelines currently.