Primary adrenal insufficiency

Autoimmune—accounts for 70%-90% of all cases of primary adrenal insufficiency... 

Secondary adrenal insufficiency occurs as a result of a pituitary gland dysfunction whereby decreased production and secretion of ACTH leads to a decrease in cortisol synthesis. Tertiary adrenal insufficiency is a disorder of the hypothalamus that results in decreased production and release of CRH, which, in turn, decreases pituitary ACTH production and release. In contrast to Addison s disease (i.e., primary adrenal insufficiency), aldosterone production is unaffected in the secondary and tertiary forms of the disease. Chronic adrenal insufficiency often has a good prognosis if diagnosed early and treated appropriately. 

Salt craving may occur in some patients with primary adrenal insufficiency. 

Dehydration, hypovolemia, and hyperkalemia (in primary adrenal insufficiency only)... 

Hyperpigmentation of skin (usually around creases, pressure areas, areolas, genitalia, and new scars) and mucous membranes. Dark freckles and patches of vitiligo may be present. Hyperpigmentation, owing to increased ACTH levels, occurs in primary adrenal insufficiency. 

Tests to Determine Diagnosis of Primary, Secondary, and Tertiary Adrenal Insufficiency ... 

Plasma Measure plasma Primary adrenal insufficiency low plasma aldosterone level. ... 

Plasma ACTH Measure plasma ACTH Primary adrenal insufficiency hypocortisolism leads to elevated plasma ... 

Fhtients may require a lower dose of glucocorticoid than those with primary adrenal insufficiency. Some patients will only require glucocorticoid replacement temporarily, which can be discontinued after recovery of the HPA axis (e.g., drug-induced adrenal insufficiency, adrenal insufficiency following treatment for Cushing s syndrome). 

Once diagnosis is confirmed, perform further testing to differentiate between primary, secondary, and tertiary adrenal insufficiency. 

Primary hypothyroidism Adrenal insufficiency Reduced Prolactin Elimination... 

A 35-year-old male with primary adrenal insufficiency would best be treated with which of the following ... 

The answer is e. (Katzung, p 672. Hardman, pp 1477—1978.) Fludrocortisone is a synthetic steroid compound that exhibits profound mineralo-corticoid activity and some glucocorticoid activity Electrolyte and water metabolisms are affected by the administration of this compound. Fludrocortisone promotes the reabsorption of Na and the urinary excretion of K and hydrogen ions in the collecting duct of the nephron. The drug is indicated for mineralocorticoid replacement therapy in primary" adrenal insufficiency... 

Adrenal gland hypofimction is associated with primary (Addison s disease) or secondary adrenal insufficiency. Adrenal insufficiency occurs when the adrenal glands do not produce enough cortisol and, in some cases, aldosterone. 

Primary adrenal insufficiency (Addison s disease) most often involves the destruction of all regions of the adrenal cortex. There are deficiencies of cortisol, aldosterone, and the various androgens. Medications that inhibit cortisol synthesis (e.g., ketoconazole) or accelerate cortisol metabolism (e.g., phenytoin, rifampin, phenobarbital) can also cause primary adrenal insufficiency. 

Patients with Addison s disease have an abnormal response to the short cosyntropin-stimulation test. Plasma ACTH levels are usually 400 to 2,000 pg/mL in primary insufficiency versus normal to low (0 to 50 pg/mL) in secondary insufficiency. A normal cosyntropin-stimulation test does not rule out secondary adrenal insufficiency. 

Treatment of secondary adrenal insufficiency is identical to primary disease treatment with the exception that mineralocorticoid replacement is usually not necessary. 

Adrenal insufficiency may result from hypofunction of the adrenal cortex (primary adrenal insufficiency, Addison s disease) or from a malfunctioning of the hypothalamic-pituitary system (secondary adrenal insufficiency). In treating primary adrenal insufficiency, one should administer sufficient cortisol to diminish hyperpigmentation and abolish postural hypotension these are the cardinal signs of Addison s disease. 

Metyrapone is used in the differential diagnosis of both adrenocortical insufficiency and Cushing s syndrome (hypercortisolism). The drug tests the functional competence of the hypothalamic-pituitary axis when the adrenals are able to respond to corticotrophin that is, when primary adrenal insufficiency has been ruled out. 

Cortisone acetate and hydrocortisone are usually the corticoids of choice for replacement therapy in patients with primary adrenocortical insufficiency (such as Addison s disease), or after adrenalectomy where both glucocorticoid and mineralo-corticoid replacement is needed. In secondary adrenal insufficiency, associated with inadequate corticotrophin (ACTH) secretion, glucocorticoid replacement alone is usually adequate [62]. 

ACTH stimulation of the adrenals will fail to elicit an appropriate response in states of adrenal insufficiency. A rapid test for ruling out adrenal insufficiency employs cosyntropin (see below). Plasma cortisol levels are measured before and either 30 minutes or 60 minutes following an intramuscular or intravenous injection of 0.25 mg of cosyntropin. A normal plasma cortisol response is a stimulated peak level exceeding 20 g/dL. A subnormal response indicates primary or secondary adrenocortical insufficiency that can be differentiated using endogenous plasma ACTH levels (which are increased in primary adrenal insufficiency and decreased in the secondary form). 

An incremental rise in plasma aldosterone generally occurs in secondary but not primary adrenal insufficiency after cosyntropin stimulation. 

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