Endocrine System Drug Therapy PDF

# Endocrine ## Drug Therapy for Hyperthyroidism and Hypothyroidism - **Hyperthyroidism** - Excessive secretions of thyroid hormone - from problems with the thyroid or too much TSH - Graves' disease; goiter - **Hypothyroidism** - Inadequate production of thyroid hormones...

# Endocrine ## Drug Therapy for Hyperthyroidism and Hypothyroidism - **Hyperthyroidism** - Excessive secretions of thyroid hormone - from problems with the thyroid or too much TSH - Graves' disease; goiter - **Hypothyroidism** - Inadequate production of thyroid hormones - Primary - thyroiditis; secondary - decreased TSH and TRH ## Hypothalamus, Pituitary Gland, and Thyroid Gland Interaction: A diagram is shown with the following: - **Hypothalamus** releases ***TRH*** (thyrotropin-releasing hormone) - **Anterior Pituitary** releases ***TSH*** (thyroid-stimulating hormone) - **Thyroid gland** releases ***Thyroid Hormones*** - **Target cells** throughout the body ## Hypothyroidism: ### Cardiovascular - Decreased cardiac output - Decreased blood pressure & heart rate - Enlarged heart ### CNS - Lethargy - Slow speech, slurring - Forgetfulness, mental sluggishness - Excessive drowsiness ### Metabolic - Cold intolerance - Subnormal temp - Weight gain ### Gastrointestinal - Decreased appetite - Constipation ### Integumentary - Dry, coarse, thick skin - Puffy face & eyelids - Dry & thin hair, thick hard nails ### Reproductive - Prolonged menstrual periods, infertility, decreased libido ### Miscellaneous - Increased susceptibility to infection ## Hyperthyroidism ### Cardiovascular - Increased cardiac output - Increased systolic blood pressure and tachycardia - Dysrhythmias ### CNS - Nervousness - Restlessness - Anxiety - Insomnia ### Metabolic - Heat intolerance - Low-grade fever - Weight loss ### Gastrointestinal - Increased appetite - Diarrhea, nausea & vomiting ### Integumentary - Moist, flushed skin (vasodilation & increased sweating) - Localized eye edema, characteristic eye changes, exophthalmos - Hair & nails soft ### Reproductive - Amenorrhea ### _Miscellaneous_ - Increased susceptibility to infection ## Drugs used for Hyperthyroid disease - Prototype: propylthiouracil – used to treat hyperthyroidism; also Methimazole - **Mechanism of action** - Decreasing production or release of thyroid hormones - **Indications for use** - hyperthyroidism secondary to: Graves' disease; nodular goiter; Thyroiditis; functioning thyroid carcinoma; Pituitary adenoma; thyroid storm - **Adverse effects** - hypothyroidism, Gl upset, - **Interactions** - anticoagulants (increased risk for bleeding) - **How do we assess effectiveness?** - **Adjuvant medication:** propranolol – beta-adrenergic blocker controlling symptoms of hyperthyroidism ## Drugs used for Hypothyroid disease - Prototype: levothyroxine - **Mechanism of action** - Provide exogenous source of thyroid hormones, best absorbed on an empty stomach - **Black Box Warning** –thyroid hormones for the treatment of weight loss - **Adverse effects** – s/s of hyperthyroidism - **Interactions** - some antidepressants and beta-adrenergic agents, nasal decongestants increase the effects of thyroid hormones; antacids, cholestyramine, iron, sucralfate decrease absorption ## Drug Therapy for Pituitary and Hypothalamic Dysfunction - **Posterior Pituitary Hormones** - Posterior pituitary gland stores and releases two hormones that are synthesized by nerve cells in the hypothalamus. - **Antidiuretic hormone (ADH)** also called vasopressin - causes water to be resorbed into the tubules - **Oxytocin** - will be addressed in Women's Health Lecture - **Diabetes Insipidus** – results from dysfunction of the posterior pituitary. Absence of Antidiuretic hormone cause the kidneys to filter water and not reabsorb it. Large urine production (4 to 30 liters), decreased circulating volume, increased thirst - **Prototype drug is desmopressin acetate; synthetic of ADH** - **Mechanism of action** -Reduces urine volume and serum osmolality, increases reabsorption of water by the kidney - **Use** – treatment of Diabetes Insipidus - **Black Box Warning** – severe hyponatremia, changes in fluid volume can result in cardiac arrest. ## Drug Therapy to Regulate Calcium and Bone Metabolism - Calcium and Bone Metabolism - Three hormones - **Parathyroid hormone (PTH)** - **Calcitonin; vitamin D** - both can be life threatening - **Hypocalcemia** - Characterized by Increased resorption of calcium & Loss of bone mass - Weaken bones - Lead to fractures, pain, disability - **Hypercalcemia** - **Principles of Drug Therapy** - Restore normal calcium balance in body and prevent - Osteoporosis treatment - Bisphosphonates, calcitonin, estrogens, and antiestrogens - Calcium carbonate or calcium citrate - oral - Oral calcium can interfere with absorption of other oral medications - IV calcium is essential for the treatment of acute, severe hypocalcemia (medical emergency) - Vitamin D - Action - increases Ca and Phosphorus absorption in the Gl tract - Adverse effect - hypercalcemia - Bisphosphonates - Inhibit calcium resorption from bone - Prototype: alendronate (Fosamax) - Action - Binds to bone and reduces breakdown - Use - treat osteoporosis in post-menopausal women and osteoporosis in men - Adverse effect – limited if taken as ordered - Take upon waking with 6-8 ox of water, at least 30 min before eating or drinking anything else. Must sit upright or stand for at least 30 minutes following administration - **Hypercalcemia** - Calcitonin - Treatment of hypercalcemia, Paget's disease, and postmenopausal osteoporosis - **Acute hypercalcemia (severe symptoms or a serum calcium level greater than 14 mg/dL) A medical emergency & Rehydration is a priority** - Administer an IV saline solution (0.9% sodium chloride) at an initial rate of 200 to 300 mL/h and then adjust it to maintain a urine output of 100 to 150 mL/h.