Adrenocortical Agents PDF

NCM 235 Drugs Acting on the endocrine system Adrenal glands are flattened bodies that sit on top of each kidney. Each gland is made up of an inner core called the adrenal medulla and an outer shell called the adrenal cortex. Adrenal cortex surrounds the medulla and consists of three layers o...

NCM 235 Drugs Acting on the endocrine system Adrenal glands are flattened bodies that sit on top of each kidney. Each gland is made up of an inner core called the adrenal medulla and an outer shell called the adrenal cortex. Adrenal cortex surrounds the medulla and consists of three layers of cells, each of which synthesizes chemically different types of steroid hormones called corticosteroids. 3 types of corticosteroids: androgens, glucocorticoids, and mineralocorticoids Adrenal cortex responds to adrenocorticotropic hormone (ACTH) released from the anterior pituitary. ACTH, in turn, responds to corticotropin-releasing hormone (CRH) released from the hypothalamus. This happens regularly during a normal day in what is called diurnal rhythm. A person who has a regular cycle of sleep and wakefulness will produce high levels of CRH during sleep, usually around midnight. A resulting peak response of increased ACTH and adrenocortical hormones occurs sometime early in the morning, around 6 to 9 am. This high level of hormones then suppresses any further CRH or ACTH release. The corticosteroids are metabolized and excreted slowly throughout the day and fall to low levels by evening. At this point, the hypothalamus and pituitary sense low levels of the hormones and begin the production and release of CRH and ACTH again. This peaks around midnight, and the cycle starts again. Adrenal insufficiency can occur: when a patient does not produce enough ACTH when the adrenal glands are not able to respond to ACTH when an adrenal gland is damaged and cannot produce enough hormones (as in Addison’s disease), or secondary to surgical removal of the glands  Adrenocortical Agents There are three types of corticosteroids: 1. androgens 2. glucocorticoids 3. mineralocorticoids Glucocorticoids stimulate an increase in glucose levels for energy increases the rate of protein breakdown decreases the rate of protein formation from amino acids, another way of preserving energy can cause lipogenesis, or the formation and storage of fat in the body, which can be available to be broken down for energy when needed Therapeutic Actions and Indications Responsible for anti-inflammatory and immunosuppressive effects Caution should be used in patients with diabetes because the glucose- elevating effects disrupt glucose control Contraindicated in the presence of an acute infection which could become serious or even fatal  beclomethasone (Beclovent) is a respiratory inhalant and nasal spray to block inflammation locally in the respiratory tract betamethasone (Celestone) is a long-acting steroid and available for systemic and parenteral use budesonide (Budecort) is a steroid for intranasal use. It relieves the signs and symptoms of allergic or seasonal rhinitis with few side effects  cortisone (Cortone) used orally and parenterally for replacement therapy in adrenal insufficiency dexamethasone (Decadron, Decilone, Oradexon) is for dermatological, ophthalmological, and inhalational use. It peaks quickly, and effects can last for 2 to 3 days. methyprednisolone (Depo-Medrol) is the drug of choice for inflammatory and immune disorders hydrocortisone (Solu-Medrol) is a powerful corticosteriod that has Prolong use causes risk of: Adrenal insufficiency (ACTH depleting) Diabetes (glucose elevating) Fluid retention (weight gaining) Protein breakdown (muscle shrinking) Immunosuppression (germs getting) Osteoporosis (bone shrinking)  Nursing Implementation 1. Administer drug daily at 8 to 9 am to mimic normal peak diurnal concentration levels and thereby minimize suppression of the hypothalamic–pituitary axis. 2. Space multiple doses evenly throughout the day to try to achieve homeostasis. 3. Use the minimal dose for the minimal amount of time to minimize adverse effects. 4. Taper doses when discontinuing from high doses or from long-term therapy to give the adrenal glands a chance to recover and produce adrenocorticoids. 5. Arrange for increased dose when the patient is under stress to supply the increased demand for corticosteroids associated with the stress reaction. 6. Use alternate-day maintenance therapy with short-acting drugs whenever possible to decrease the risk of adrenal suppression. 7. Do not give live virus vaccines when the patient is immunosuppressed because there is an increased risk of infection. 8. Protect the patient from unnecessary exposure to infection and invasive procedures because the steroids suppress the immune system and the patient is at increased risk for infection. 9. Assess the patient carefully for any potential drug–drug interactions to avoid adverse effects. Mineralocorticoids Affect electrolyte levels and homeostasis Classic mineralocorticoid is aldosterone Aldosterone holds sodium and water in the body and causes the excretion of potassium by acting on the renal tubule Include  cortisone  fludrocortisone (Florinef)  hydrocortisone (Cortef) Indications: Partial replacement therapy in cortical insufficiency conditions, treatment of salt-losing adrenogenital syndrome Off-label use: treatment of hypotension Actions: Increases sodium reabsorption in the renal tubules and increases potassium and hydrogen excretion, leading to water and sodium retention. Adverse effects: frontal and occipital headaches arthralgia weakness increased blood volume edema hypertension heart failure rash anaphylaxis  Nursing Implementation 1. Use only in conjunction with appropriate glucocorticoids to maintain control of electrolyte balance. 2. Increase dose in times of stress to prevent adrenal insufficiency and to meet increased demands for corticosteroids under stress.  Nursing Implementation 3. Monitor for hypokalemia (weakness, serum electrolytes) to detect the loss early and treat appropriately. 4. Discontinue if signs of overdose (excessive weight gain, edema, hypertension, cardiomegaly) occur to prevent the development of more severe toxicity.