Endocrine Abstracts

Mrs SP was a 50-year old patient who presented with typical features of Cushing’s syndrome in 2003 and proceeded to pituitary surgery. Following this she was not cured, and elected to have a bilateral adrenalectomy. Following this, she was initially commenced on hydrocortisone 30 mg daily taken as 15 mg in the morning, 10 mg at noon and 5 mg at 1600 h, and fludrocortisone 100 μg daily. She continued on this for 10 years, but switched her glucocorticoid replacement to once daily prednisolone (7.5 mg). She developed diarrhoea and vomiting in 2015 due to an infection and the dose was increased to 15 mg for a day, and then reduced as she recovered. Prednisolone levels were measured as the dose was tapered (see figure) and an 8 h level on 10 mg was 120.2 μg/l and on 7.5 mg was 96.7 μg/l (target: 10 μg/l–20 μg/l). Given the high 8-hour serum concentrations, the dose was reduced to 5 mg daily, on which she feels well. Another prednisolone day profile is planned on 5 mg, with a view to reducing this further if appropriate. The conversion for hydrocortisone to prednisolone has traditionally been 4:1, but given that she feels better on 5mg prednisolone daily, would suggest a ratio of 6:1.

Once daily low dose prednisolone is a safe and effective replacement for patients who have had a bilateral adrenalectomy, and levels at 8h are a useful guide to dose adjustments.