4 Corticosteroids

Corticosteroid groups and effects

Corticosteroids include two groups with different primary effects. Glucocorticoids, such as hydrocortisone and prednisone, reduce inflammation and immune activity. Mineralocorticoids, such as aldosterone and fludrocortisone, help retain sodium and water and increase potassium excretion. Some drugs, including hydrocortisone, have effects in both groups.

Glucocorticoid uses

Systemic glucocorticoids are used to treat inflammatory or autoimmune disease for their anti-inflammatory and immunosuppressive effects. Uses include some allergic, autoimmune, and inflammatory conditions. They can also replace cortisol when the body does not produce enough.

Risks of prolonged glucocorticoid use

Prolonged glucocorticoid use can raise blood glucose, weaken immune defenses or mask signs of infection, contribute to bone loss, and cause HPA-axis suppression. These risks generally increase with greater dose and duration.

Suppression and safe tapering

Prolonged glucocorticoid exposure can suppress ACTH and the body's own cortisol production. The adrenal glands may not produce enough cortisol immediately after the medication is stopped, particularly during illness, surgery, or another major stress. This can cause adrenal insufficiency or, in severe cases, adrenal crisis.

When the treated condition is controlled and glucocorticoids are no longer needed after long-term treatment, tapering should be directed by the prescribing clinician. The dose can generally be reduced more quickly while above a physiologic dose and more slowly near a physiologic dose, such as about $4\text{–}6$ mg prednisone daily. Abruptly stopping long-term treatment is not the recommended approach.

Short courses of less than $3\text{–}4$ weeks generally do not require tapering to prevent HPA-axis suppression. Treatment plans should be individualized.

Fludrocortisone replacement and monitoring

Fludrocortisone provides mineralocorticoid replacement for a person with primary adrenal insufficiency and confirmed aldosterone deficiency. It promotes sodium and water retention and potassium loss; excessive mineralocorticoid effect can cause ankle swelling or other edema, high blood pressure, and low serum potassium.

Monitoring includes blood pressure and electrolytes. For replacement, clinical findings such as salt craving, postural blood pressure, and edema are also considered. Fludrocortisone is not routinely used for glucocorticoid-induced adrenal insufficiency, where aldosterone production is generally preserved.