Endocrine Abstracts

JOINT3785

High dose prednisolone is commonly used for many inflammatory conditions. A 70-year old woman was referred to the endocrine clinic with a history of long term steroid exposure for eosinophilic granulomatosis with polyangitis (EGPA) which she continued for over ten years. She subsequently commenced biologic treatment for eosinophilia but continued on steroid treatment. She was switched to thrice daily hydrocortisone and the minimum dose she could tolerate was 5 mg on waking, 5 mg at midday and 2.5 mg in the afternoon. She remained on this dose for several years. In May 2024 she was referred to our centre to switch to once daily, low dose prednisolone. Prior to switching her 8am cortisol and ACTH values were undetectable. Following the switch to once daily prednisolone, day curves were arranged to optimize her dose. Prednisolone 3mg/day produced an 8hour level of 30 µg/l (normal values 15 to 25 µg/l). We advised her to reduce to 2mg prednisolone once a day. The patient was keen to try and reduce her steroids, therefore she commenced a weaning protocol to 1mg daily and a prednisolone level on 1mg demonstrated this was a suppressive dose for this patient. A short synacthen test (SST) on 1 mg of prednisolone per day demonstrated showed the following results T=0min cortisol <28nmol/l ACTH <5ng/l T=30min cortisol 45nmol/l T=60min cortisol 59nmol/l In order to go below 1mg of prednisolone she switched to an equivalent dose of hydrocortisone 7.5mg once a day which has a shorter half-life. A hydrocortisone day curve confirmed that she was a slow metabolizer of hydrocortisone SST was repeated in on 5mg; T=0min cortisol 111nmol/l, ACTH 45.6ng/l T=30min cortisol 120nmol/l T=60 min cortisol 125nmol/l She continues to wean from 5mg day to 2.5mg according to the protocol below and we aim to wean her off steroids completely. Individualised care for patients on long term steroids wishing to wean is paramount to success. Supporting patients to wean off steroids negates risks such as osteoporosis and diabetes caused by long term steroid use. These results suggest that conventional hydrocortisone replacement in doses as low as 7.5mg/5mg/2.5mg can cause persistent HPA axis suppression. There is a need for prospective studies to evaluate weaning protocols.