Metabolism

• Endocrine system


  • Consists of glands that secrete hormones
  • Maintains homeostasis using hormones as chemical messengers
• Hormone release


  • Commonly controlled by negative feedback
  • One hormone may control another
• Negative feedback is common for the last hormone in a pathway to provide feedback
• Hormone pharmacotherapy


  • Hormones used as replacement therapy, antineoplastics, or for natural therapeutic effects
  • Hormone blockers used to inhibit actions of certain hormones
• Selected endocrine disorders and their pharmacotherapy


  • Cushing syndrome
  • Addison disease
  • Menstrual and metabolic dysfunction
  • Dysfunctional uterine bleeding
  • Hypogonadism
  • Diabetes mellitus
  • Hyperparathyroidism
  • Hypoparathyroidism
  • Diabetes insipidus
  • Syndrome of inappropriate antidiuretic hormone (SIADH)
  • Small stature
  • Acromegaly
  • Delayed delivery or lack of milk ejection
  • Graves disease
  • Myxedema (adults), cretinism (children)
• Hypothalamus


  Secretes releasing hormones that tell the pituitary gland which hormones should be released
• Posterior pituitary


  Releases hormones in response to nerve signals from the hypothalamus
• Selected hypothalamic and pituitary drugs


  • bromocriptine
  • desmopressin
  • lanreotide
  • mecasermin
  • octreotide
  • pasireotide
  • pegvisomant
  • somatotropin
• Desmopressin is the most common form of antidiuretic hormone (ADH) used to treat diabetes insipidus
• Desmopressin is available as a nasal spray, oral, intravenous, and subcutaneous formulations
• Severe respiratory impairment


  In severely obese patients with Prader-Willi syndrome, diabetes, pancreatitis, scoliosis of the spine, papilledema, intracranial tumor
• Somatotropin


  A growth hormone
• Ritchie is shorter in stature than his twin sister, Dawn

  It would be appropriate to give him growth hormones
• Antidiuretic hormone (ADH)


  Conserves water in body, Excreted from the posterior pituitary when the feedback loop indicates concentrated serum/high serum sodium
• Diabetes insipidus


  Caused by deficiency of ADH
• Desmopressin (DDAVP)


  Most common form of ADH, Forms: nasal spray, oral, intravenous, subcutaneous
• James is 96 years old and resides in a nursing home


  He was recently diagnosed with diabetes insipidus and prescribed desmopressin
• Role of the Nurse: Antidiuretic Hormone Therapy for ADH Deficiency

  1. Assess for electrolyte imbalances, weight, I & O

  2. Assess for changes in specific gravity and fluid intake

  3. Monitor serum sodium and potassium levels

  4. Monitor urine specific gravity, routine urinalysis

  5. Assess vital signs, especially blood pressure and pulse

  6. Assess neurologic status: Symptoms of headache, Changes in mental status: drowsiness, confusion

  7. Advise patients to avoid alcohol
• Glucocorticoids


  Mobilize body for long-term stress, Influence carbohydrate, lipid, and protein metabolism in most cells
• Mineralocorticoids


  Aldosterone promotes sodium reabsorption and potassium secretion (like potassium-sparing drugs!)
• Gonadocorticoids


  Mostly male sex hormones (androgens)
• Control of Glucocorticoids


  1. Hypothalamus releases corticotropin-releasing factor (CRF)

  2. Causes adrenocorticotropic hormone (ACTH) to be secreted by pituitary

  3. Adrenal cortex releases glucocorticoids

  4. When cortisol level rises, negative-feedback mechanism shuts off further release of glucocorticoids
• Addison Disease


  Primary adrenocortical insufficiency, Deficiency of both corticosteroids and mineralocorticoids, Symptoms: Nausea, vomiting, lethargy, confusion, and coma, Low plasma cortisol, accompanied by high plasma ACTH levels
• Adverse Effects of Long-Term Corticosteroid Therapy


  • Behavioral changes
  • Eye changes
  • Immune response
  • Metabolic changes
  • Myopathy
  • Osteoporosis
  • Peptic ulcers
• ACTH and related agents


  Rarely used as medications, Must be given parenterally and have many side effects, Primary use is to diagnose adrenal disorders
• Joe has had osteoarthritis for the past 10+ years


  He is having an acute flare-up of the arthritis with severe joint pain and inflammation, His health care provider prescribed a 10 day course of hydrocortisone
• Hydrocortisone (notice all the other drugs on that table end in "one" and have ALL the same adverse effects.)
• Cushing Syndrome
• Antiadrenal Drugs


  Used to treat severe Cushing syndrome, Occurs with prolonged glucocorticoid therapy, Inhibits corticosteroid synthesis, Antiadrenal drugs not curative, Use usually limited to 3 months of therapy
• Role of the Nurse: Antiadrenal Therapy for Adrenocortical Insufficiency


  1. Assess and monitor lab values: Platelet count, bilirubin, hepatic-function tests, and prothrombin

  2. Assess for jaundice, bruising, bleeding

  3. Monitor patient's stress level

  4. Monitor for orthostatic hypotension and dizziness

  5. Assist with ambulation

  6. Caution patient to change positions slowly