Endocrine Abstracts

Opioids –Yet another Cause for Adrenal Insufficiency. Opioid prescriptions have almost doubled in the last decade in the UK. Opioid related hypogonadotropic hypogonadism is a well-recognised clinical entity. Opioid therapy as a cause of adrenal insufficiency is an under-recognised endocrinopathy with potentially lifethreatening adverse effects. We present the case of a 57 year old lady referred to the endocrine clinic with symptoms of generalised fatigue and weakness. Her only medication was moderately high dose of morphine sulphate which she has been on for chronic back pain. Her 9 AM cortisol was 113 nmol/l (200–500 nmol/l). A subsequent Short Synacthen test (SST) showed basal cortisol of 32, 30 min level at 526 and 60-min level at 649 nmol/l. Her ACTH level was undetectable at <5 ng/l. Her other pituitary bloods were unremarkable except for FSH (21.4 U/l) and LH (1.3U/l) with estradiol (<44 pmol/l) levels. Her MR pituitary imaging was normal. Treatment with hydrocortisone 5 mg three times a day has not led to an improvement of symptoms. Opioids suppress the HPA axis via kappa and delta receptors resulting in suppression of CRH release and thus affecting ACTH levels. It appears as though there is a female gender preponderance to this effect of opioids. One study showed patients on higher doses of opioids equivalent to morphine 62 mg daily or more showed a blunted response to SST. The fact that she was on a smaller dose of morphine and the fact that we cannot ascertain the actual onset of ACTH deficiency might explain the normal response to ACTH. The optimum management and long term outcome of patients with this condition is not currently known.