When patients who are receiving glucocorticoid therapy (for example, with prednisone) need to stop taking it, the doctor will prescribe a series of doses of tapering size to gradually lower the dose rather than suddenly stop it. Explain this dosage strategy in terms of the negative feedback control of cortisol secretion.

Question

blues · Answer

Cortisol secretion is stimulated by release of corticotropin releasing hormone by the hypothalamus, which in turn stimulates adenocorticotropin release from the anterior pituitary which finally stimulates release of cortisol by the adrenal cortex. It turns out that cortisol inhibits both corticiotropin release and adenocorticotropin release. This is negative feedback.

When taking a patient off an exogenous source of cortisol, the body needs time to up regulate production of corticotropin and adenocorticotropin. If the patient is taken off too abruptly, the body does not have time to adapt and there will not be enough of the intermediate hormones present to stimulate production of enough cortisol to meet the body's needs.

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