Hypopituitarism & Diabetes Insipidus

Endocrine Disorders: Hypopituitarism & Diabetes Insipidus

• Endocrine disorders covered are hypopituitarism and diabetes insipidus.

Pituitary Hormones

• Hormones from the pituitary gland control the function of many target glands and cells.
• The anterior pituitary makes 5 types of hormones:
  • Thyrotrophs-TSH
  • Corticotrophs-ACTH
  • Gonadotrophs-LH, FSH
  • Somatotrophs-GH
  • Lactotrophs-Prolactin
• The posterior pituitary makes 2 types of hormones:
  • Oxytocin
  • Antidiuretic Hormone [ADH]

Disorders of the Anterior Pituitary Gland: Hypopituitarism

• Hypopituitarism is characterized by hyposecretion of hormones.
• The most common hormones affected are growth hormone, LH, and FSH.
• Common causes:
  • Pituitary tumors
  • Autoimmune disorders
  • Infections
  • Pituitary gland destruction from trauma, radiation, or surgery

Hypopituitarism Deficiencies

• Hormone deficiencies in hypopituitarism can lead to end-organ failure.
• LH & GH deficiencies cause lack of ovary/testes development, potentially causing infertility.
• TSH causes thyroid dysfunction and metabolism problems.
• ACTH causes adrenal insufficiency, shock, and potentially death.

Endocrine Drug Therapy

• Replacement therapy addresses hormone deficiencies.
• Drug therapy helps produce a specific hormone response when a hormone deficiency is present.
• Diagnostic testing is used to determine hypofunction or hyperfunction of specific hormones.
• Mechanism of Action: depends on the drug and either augments or antagonizes the natural effects of pituitary hormones.

Hypopituitarism: Tumor Clinical Manifestations

• Vary based on the degree and speed of onset of pituitary dysfunction.
• Symptoms: headaches, visual changes, anosmia (loss of smell), and seizures due to the presence of a tumor.

Hypopituitarism: Growth Hormone (GH) Deficiency

• Truncal obesity.
• Decreased muscle mass and strength.
• Decreased energy and reduced exercise capacity.
• Flat affect, depression, and psychological instability.

Growth Hormone (GH) Deficiency: Drug Therapy

• Replacement therapy includes somatropin & somatrem:
  • Recombinantly made growth hormone (GH).
  • They stimulate skeletal growth in patients with deficient GH.
• Adverse effects: headache, hyperglycemia, hypoglycemia, hypothyroidism, and inflammation at the injection site.
• Teaching: Parents of children who are receiving growth hormones should keep a journal reflecting the child's growth.
• Therapeutic effect: Increased growth

Growth Hormone (GH) Excess: Drug Therapy

• Octreotide (Sandostatin) antagonizes the effects of natural GH and inhibits GH release.
• It treats Carcinoid tumors secreting VIP (vasoactive intestinal polypeptide).
• VIP causes profuse, watery diarrhea.
• Octreotide reduces severe diarrhea, flushing, and potentially life-threatening hypotension that may occur.

Octreotide (Sandostatin)

• Adverse effects include fatigue, headache, hypo/hyperglycemia, nausea/vomiting/diarrhea, dyspnea, arthralgia, and cardiac arrhythmias.
• Nursing implications:
  • May impair gallbladder function—instruct patient to report abdominal pain.
  • Use with caution in patients with renal impairment and monitor glucose levels.
  • Can be given IV, IM, or SC.
  • Interacts with Cyclosporine and Ciprofloxacin; used for transplant.
• Therapeutic response: Decreased VIP related diarrhea and decreased rate of growth.

Hypopituitarism: Adrenocorticotropic Hormone (ACTH) Deficiency

• Clinical manifestations:
  • Weakness, fatigue, and headache.
  • Dry, pale skin and diminished axillary hair.
  • Postural hypotension and fasting hypoglycemia.
  • Diminished tolerance for stress and poor resistance to infections.

ACTH Deficiency: Drug Therapy

• Replacement therapy: cosyntropin (Cortrosyn)
  • Administered IM, SQ, IV, or rectally
  • It stimulates the release of cortisol from the adrenal cortex.
  • Its effects are anti-inflammatory and promotes renal retention of sodium.
• Side effects: may result in edema and HTN.
• Nursing Implications:
  • Follow administration directions carefully and maintain adequate hydration.
  • Decrease sodium and potassium intake.
  • Avoid vaccinations during drug therapy.
• Therapeutic response: Improved pain & comfort

Posterior Pituitary Gland

• Secretes hormones including:
  • Oxytocin: stimulates uterine contractions in labor and the let-down of milk in breastfeeding women.
  • Antidiuretic hormone (ADH): controls the concentration of body fluids and conserves water in the kidneys.

Diabetes Insipidus

• Central DI: Decreased secretion of ADH.
  • Causes: Idiopathic, head trauma, pituitary tumor, neurosurgery
• Nephrogenic DI: Kidney resistance to ADH.
  • Causes: Lithium toxicity, renal disease, hypokalemia, pregnancy, medications
• Primary DI damage to thirst regulation, often associated with mental illness.

Diabetes Insipidus: ADH Deficiency

• Characterized by a deficient production of antidiuretic hormone (ADH).
• ADH regulates the fluid volume in the body by stimulating reabsorption of water in the renal tubules.
• ADH release causes the renal tubules to reabsorb water, creating a more concentrated urine (water stays in, solutes go out).
• When ADH is inhibited, renal tubules do not reabsorb water, creating a more dilute urine (water goes out).

Diabetes Insipidus: Results and Characteristics

• Fluid and electrolyte abnormalities.
• Increased urinary output along with increased plasma (serum) osmolality (increased Na+ concentration).
• Decreased urine osmolality (increased H2O decreased solutes).
• It is a transient or chronic problem.

Diabetes Insipidus: Clinical Manifestations

• Polydipsia to compensate for fluid loss.
• Polyuria of 5-20 L/Day.
• Low specific gravity of urine and urine osmolality (low solutes).
• Hypernatremia (serum Na+) due to water loss from kidneys.
• Nocturia and generalized weakness.
• Weight loss and constipation.
• Poor skin turgor and dehydration.
• Hypotension and tachycardia.
• Irritability leads to mental dullness and can lead to a comatose state.
• Shock.

Anti-Diuretic Hormone (ADH) Deficiency: Drug Therapy

• Vasopressin and desmopressin are used to treat ADH deficiency.
• Vasopressin and desmopressin increase water resorption in distal tubules and collecting ducts of the nephrons.
• Urine becomes more concentrated and reduces water excretion by up to 90%.
• Vasopressin: A powerful vasoconstrictor used for hypotensive emergencies, GI bleeding, and esophageal variceal bleeding.
• Desmopressin: Used for dose-dependent treatment of blood disorders by increasing plasma level factors (i.e., factor VIII); also used for nocturnal enuresis (bedwetting).

Desmopressin/Vasopressin: Nursing Implications

• Can be given nasal, IV, or IM.
• Use cautiously in patients with seizure disorders, asthma, cardiovascular disease and renal disease.
• Monitor IV site carefully if infiltration occurs, as severe tissue damage and possible necrosis can occur.
• Interacts with Carbamazepine (anti-seizure medication) and can enhance the antidiuretic effect.
• Interacts with Norepinephrine (Vasopressor to increase blood pressure) and can reduce the antidiuretic effect.
• Desmopressin can be administered nasally, orally, IV, or IM.

Desmopressin/Vasopressin: Effects

• Adverse effects include hypertension, fever, vertigo, headache, nausea/heartburn/abdominal cramps, uterine cramping, nasal irritation/congestion, tremors, and sweating.
• Therapeutic effect: Reduce severe thirst and decrease urinary output.

Nursing Implications for Endocrine Drugs

• Obtain thorough nursing assessment and medication history.
• Assess for contraindications specific to each drug.
• Assess medication history for possible interactions.
• Rotate injection sites and don't discontinue drugs abruptly
• Do not take over-the-counter products without checking with a healthcare provider.
• Monitor for adverse effects.

Social Determinants of Health (SDOH)

• Average cost of Somatropin per month: $800 - $3,000.
• Octreotide: $125 for 10 vials (10 doses).
• Cosyntropin: $96 per dose.
• Vasopressin: $412 for 5mL, generic med $88 for 5 mL, 10mcg per inhale.
• Desmopressin: $475 per bottle, 5 mL.