💊 Hydrocortisone

Hydrocortisone is a short-acting glucocorticoid, a type of corticosteroid. It is the synthetic equivalent of cortisol, the primary endogenous glucocorticoid produced by the adrenal cortex.

It exerts its effects by binding to intracellular glucocorticoid receptors, forming a complex that translocates to the nucleus. This complex modulates gene expression, leading to widespread anti-inflammatory, immunosuppressive, and metabolic effects.

Hydrocortisone is used for physiological replacement in adrenal insufficiency (e.g., Addison's disease, congenital adrenal hyperplasia). It is also used as an anti-inflammatory and immunosuppressant in various conditions, including severe allergic reactions, asthma exacerbations, and inflammatory bowel disease. Intravenous hydrocortisone is crucial for managing adrenal crisis.

Absolute contraindications include systemic fungal infections (unless treated) and hypersensitivity. Relative contraindications include active untreated infections, peptic ulcer disease, uncontrolled diabetes, and severe osteoporosis, where the risks must be carefully weighed against the benefits.

Common adverse effects include fluid retention, hypertension, hyperglycaemia, increased susceptibility to infection, and mood disturbances. Long-term use can lead to Cushingoid features, osteoporosis, adrenal suppression, and skin thinning. Gastrointestinal upset and insomnia are also frequently reported.

Regular monitoring of blood pressure, blood glucose, and electrolytes is important, especially during long-term therapy. Growth in children and bone mineral density in adults on prolonged treatment should also be considered. Clinical assessment for signs of infection or Cushing's syndrome is ongoing.

When prescribing, always check for known allergies, especially to other corticosteroids. Be mindful of drug interactions, particularly with NSAIDs (increased GI bleed risk), diuretics (electrolyte imbalance), and CYP3A4 inhibitors/inducers. Counsel patients on the importance of not abruptly stopping treatment, the need for 'sick day rules' for adrenal insufficiency, and potential side effects like increased infection risk.

Hydrocortisone is the first-line treatment for adrenal insufficiency and adrenal crisis. Remember the 'sick day rules' for patients on replacement therapy – increasing the dose during illness or stress. Be aware of its short half-life compared to other corticosteroids. It's a key drug in emergency medicine for anaphylaxis and severe asthma.

SBAs often test the recognition of adrenal crisis and the immediate need for IV hydrocortisone. Questions may also focus on distinguishing between physiological replacement and immunosuppressive doses, or on the management of patients on long-term steroids during acute illness (stress dosing). Another common theme is the side effect profile, particularly adrenal suppression.