Pharmacology Exam 3 Study Guide PDF

PHARMACOLOGY EXAM 3 STUDY GUIDE Thyroid & Parathyroid Disorders: Basic Concepts: -​ Pituitary gland: “Master gland” - controls everything else -​ Hypothalamus sends messages to the pituitary gland and tells it to do something -​ End organs: Thyroid gland, adrenal cortex Endocrine Assessme...

PHARMACOLOGY EXAM 3 STUDY GUIDE Thyroid & Parathyroid Disorders: Basic Concepts: -​ Pituitary gland: “Master gland” - controls everything else -​ Hypothalamus sends messages to the pituitary gland and tells it to do something -​ End organs: Thyroid gland, adrenal cortex Endocrine Assessment: -​ Need to know current and past medical history ○​ Where do they work? Car accident recently? -​ Blood levels -​ Urinalysis Endocrine Treatments: -​ Hormone replacement therapy -​ Suppression of hormone overproduction Thyroid: -​ Butterfly-shaped gland located in the neck -​ Iodine is required for synthesis & it comes from diet -​ Iodine does promote thyroid hormone synthesis, but when there's too much iodide, the thyroid reduces hormone production as a protective mechanism. This is why high doses of iodide (like potassium iodide) can temporarily reduce thyroid hormone levels in conditions like hyperthyroidism. -​ Hormones of thyroid gland: Triiodothyronine (T3) & Thyroxine (T4) -​ Thyroxine (T4): used to regulate body metabolism -​ Thyroid disorder more common in women  -​ Primary thyroid disorders are the most common: the thyroid gland is the one that is dysfunctional Goiter: -​ Enlargement of the thyroid -​ May develop with: ○​ Excess TSH (thyroid stimulating hormone, comes from pituitary gland) ○​ Low iodine levels ​ Low iodine levels = low thyroid hormone synthesis = pituitary thinks its his fault and compensates by increasing TSH ○​ Goitrogens: foods or other substances that promote thyroid gland enlargement Hypothyroidism: Low thyroid levels (insufficient T3 and T4) Causes: a.​ Hashimoto's Thyroiditis: most common cause -​ Autoimmune disorder b.​ Drugs, genetics, thyroiditis (postpartum period), congenital hypothyroidism (born with it) Signs and symptoms: parasympathetic nervous system (SLOWWWS stuff down) “ Thyroxine (T4) regulates the body’s metabolism, so if we do not have enough of it everything starts to slow down” -​ Cold intolerance -​ Weight gain -​ Lethargy -​ Fatigue -​ Memory deficits -​ Poor attention span  -​ Muscle cramps -​ Constipation -​ Decreased fertility -​ Puffy face -​ Hair loss -​ Brittle nails Systemic Effects: throughout the body -​ Reduced LDL receptors = hyperlipidemia -​ “There’s not a lot of LDL receptors, so they are not pairing up with things so then it is causing hyperlipidemia” -​ Elevated carotene = yellow/orange skin -​ Decreased hematopoiesis = anemia -​ Decreased renal function = increased susceptibility to drug toxicity -​ Because the kidneys are not filtering it correctly -​ Myxedema = severe hypothyroidism -​ Critical patient, must do something immediately Diagnosis and Treatment: -​ Primary: High TSH, low free T3 & T4 -​ There's a problem with the actual thyroid, so it is not responding and is resistant to the TSH being sent to it. -​ Treatment: hormone replacement (Levothyroxine) to mimic T3 and T4 or help it to no longer be resistant​ -​ Secondary: Low TSH, low free T3 & T4 -​ Something is wrong with the pituitary sending TSH -​ Tumor is usually the cause -​ Treatment: Surgical intervention to remove tumor -​ Hashimoto's Thyroiditis: Levels get lower and lower  -​ Antithyroglobulin (anti-Tg) -​ Antithyroperoxidase (anti-TPO) -​ Myxedema Coma: SEVERE hypothyroid condition -​ Will progress to confusion and coma if not treated -​ Ultrasound -​ Blood laboratory values/screening tests Hyperthyroidism: elevated free T3 & T4 Causes: -​ Graves Disease: -​ Most common cause -​ “Thyroid-stimulating antibodies bind to and activate thyroid tropin receptors within the gland and cause the gland to enlarge and continuously make thyroid hormones” -​ Autoimmune stimulation of the thyroid gland -​ Subacute thyroiditis -​ Postpartum period thyroiditis (HCG is similar to TSH) -​ Thyroid adenoma (tumor) -​ Excessive TSH -​ Toxic multinodular goiter (TMG) -​ Excessive iodine ingestion -​ Jod Basedow Syndrome Signs and Symptoms: -​ Nervousness -​ Insomnia -​ Sensitivity to heat -​ Weight loss -​ Enlarged thyroid gland  -​ Atrial fibrillation -​ Increased heart rate -​ Increased SNS sensitivity -​ Exophthalmos: wide-eyed stare, extraocular area filled with mucopolysaccharides -​ Graves Ophthalmopathy: periorbital edema and bulging of the eyes Diagnosis and Treatment: -​ Graves disease, give them antithyroid hormone medication (PTU, carbimazole) -​ Radioactive Iodine Uptake (RAIU) Test (warm, hot, cold nodules) -​ Radioactive I-131 Ablation -​ Surgical intervention -​ Ultrasound with color doppler evaluation -​ Blood levels (TRH, TSH, T4, T3) -​ Biotin supplements can interfere with thyroid test accuracy HYPOthyroidism (SLOWWW) HYPERthyroidism (FASTTT) Hypercholesterolemia Exophthalmos Gains weight easily Loss of weight Sluggishness/fatigue/lethargy Anxiety Feeling cold Feeling warm Delayed reflexes Tremors Constipation Tachycardia & A-fib Decreased fertility Decreased fertility Thyrotoxic Crisis (Thyroid Storm): -​ Overwhelming release of thyroid hormones (lots of free T3 & T4) -​ LOW TSH levels -​ Stimulate metabolism -​ Often precipitated by surgery or trauma -​ Medical emergency (Heart failure and pulmonary edema) Management: -​ Decrease thyroid hormone synthesis (Methimazole or PTU) -​ Inhibit thyroid hormone secretion (Oral potassium iodide or IV sodium iodide) -​ Reduce heart rate (Beta blocker/CCB) -​ Support the circulation with stress doses of IV glucocorticoids Thyroid Nodules: -​ Most asymptomatic -​ Can occur with hypothyroidism or hyperthyroidism -​ Single nodule (lump in neck): increased risk of it being cancerous -​ Multiple nodules (lumps in neck): often benign -​ Ultrasound and needle biopsy for diagnosis -​ Technetium scan (is it a hot, warm, or cold nodule) -​ Hot = hyperactive nodule -​ Cold = hypoactive nodule -​ Warm = just right nodule Malignant Thyroid Nodule: (cancerous) Risk: -​ < 20 years old or >70 years old -​ Male -​ Hx of neck irradiation -​ Firm, hard, or immobile nodule ​ Presence of cervical lymphadenopathy Parathyroid Gland: inside of thyroid gland -​ Four pea-sized glands on posterior thyroid -​ Secrete PTH (parathyroid hormone) -​ Released when blood calcium is LOW -​ Activates bone reabsorption -​ Activates intestinal calcium absorption by the kidneys Hypoparathyroidism: -​ Rare -​ Due to inadvertent damage (thyroid surgery) -​ S/S same as hypocalcemia -​ Treatment: replacement PTH and calcium and vitamin D supplementation -​ If PTH is low, then so is calcium bc they go together) Hyperparathyroidism: -​ Parathyroid tumor -​ Primary: Elevated PTH and calcium (they go together) -​ Secondary: In response to hypocalcemia, it increases -​ Treatment: Remove the tumor and reduce serum calcium levels  Thyroid Medications: Classification Therapeutic Use MOA Adverse Effects Examples Thyroid Hypothyroidism Synthetic form of Few if any when correct dose is Levothyroxine Hormone thyroxine (T3, T4 or used (Synthroid) Replacement Myxedema coma both) If dose is too high: Start with low Suppression of Tremors​ dose and then TSH in the Headache slowly increase treatment & Nervousness prevention of Palpitations goiters Tachycardia Loss of hair N/V/D Antithyroid Hyperthyroidism Trying to LOWER T3 N/V/D Propylthiouracil Agents (Graves) and T4 Severe liver toxicity (PTU) and Methimazole (Thioamides) Blocks synthesis of Causes bone marrow (Tapazole) thyroid hormones suppression (must have frequent blood tests) Prevent formation of thyroid hormone within the thyroid cells, lowering the serum level Antithyroid Thyroid cancer Destroys thyroid Hypothyroidism Radioactive Agents producing cells Iodism (metallic taste in mouth) Iodine (RAI) Staining of teeth (Iodine Want to stop the cancer Skin rash Solutions) from forming Goiter development Antithyroid Thyrotoxic Inhibits thyroid Hypothyroidism Potassium Agents crisis/storm production & hormone Iodism (metallic taste in mouth) Iodide (Losat, release due to high Staining of teeth Thyrosafe, Pre-thyroidectomy levels of iodine Skin rash Thyroshield) Goiter development  Parathyroid Medications: Classificatio Therapeutic MOA Adverse Effects Examples n Use Synthetic Hypocalcemia Regulate absorption GI effects Calcitriol Vitamin D of calcium and Analog phosphate from CNS effects small intestine Patients with liver or renal dysfunction Mineral may experience increased level of drugs reabsorption in bone and/or toxic effects Reabsorption of Hypercalcemia phosphate from renal tubes Interruption of treatment: severe hypocalcemia Antihyperca Treatment of Act to slow or block Most common: abdominal pain, Bisphosphona lcemic Paget’s Disease bone resorption constipation, musculoskeletal pain, nausea, tes Agents diarrhea Paget’s disease: Alendronate too much Increase in bone pain with Paget’s disease (Fosamax) calcium Esophageal ulceration Long-term use: increased risk of femoral shaft fractures Osteonecrosis of the jaw Antihyperca Lower calcium Balance the effects Flushing of the face and hands, skin rash, Calcitonins lcemic levels of PTH nausea and vomiting, urinary frequency, Agents Calcitonin Inhibit bone Local inflammation at the site of injection salmon resorption (Miacalcin) Intranasal route: nasal dryness and irritation Many of the side effects lessen with time  Case Study: Thyroid and Parathyroid Agents a. What are the key nursing intervention considerations for patients receiving antithyroid agents? -​ Administer methimazole and PTU three times daily at 8-hour intervals for consistent drug levels. -​ Give iodine solution with a straw to prevent tooth staining; tablets can be crushed if needed. -​ Monitor patient response and arrange periodic blood tests to evaluate effectiveness and detect adverse effects. -​ Watch for signs of iodism (e.g., metallic taste, sore gums) and discontinue iodine solution immediately if symptoms appear. -​ Provide patient education on avoiding adverse effects, recognizing warning signs, and the importance of regular follow-up for long-term therapy adherence. b. What are the most common adverse effects of calcitriol? -​ GI Effects: Metallic taste, nausea, vomiting, dry mouth, constipation, and anorexia. -​ CNS Effects: Weakness, headache, drowsiness, and irritability due to electrolyte changes. -​ Liver/Renal Dysfunction: Increased drug levels or toxicity in patients with impaired liver or kidney function. -​ Calcium Imbalance: Severe hypocalcemia with treatment interruption; hypercalcemia when initiating or increasing the dose. c. What are the indications for levothyroxine? -​ Replacement therapy for hypothyroidism. -​ Suppresses TSH release to manage thyroid conditions. -​ Treats myxedema coma and thyrotoxicosis. -​ Synthetic hormone option for patients allergic to desiccated thyroid products. d. What are the lifespan considerations for a child receiving thyroid and parathyroid agents?  -​ Hypothyroidism Treatment: Levothyroxine is the drug of choice, with dosing based on thyroid hormone levels, growth, and development. Doses for children are typically higher due to their higher metabolic rate. -​ Regular Monitoring: Growth records and thyroid function should be closely monitored to adjust the dose as the child grows. After puberty, the dose typically aligns with adult levels. -​ Antithyroid Agents: Methimazole is preferred due to lower liver toxicity. Propylthiouracil (PTU) is no longer recommended. Radioactive agents are avoided due to potential radiation effects on developing cells. -​ Hypercalcemia: Rare in children but may occur with malignancy -​ Bisphosphonates may be used for malignancy-related hypercalcemia, with dose adjustments based on age and weight. Serum calcium levels should be closely monitored. What She Mentioned During Review: -​ Hypothyroidism: everything slows down -​ Hypothyroidism is most likely caused by autoimmune -​ Hashimotos is for hypo and Graves is for hyper -​ Myxedema coma is for hypothyroidism (CRITICAL) -​ Thyroid storm is for hyperthyroidism (CRITICAL) -​ Treat hypothyroidism with thyroid supplements (levothyroxine) -​ Pituitary gland communicates to thyroid with TSH -​ Treat hyperthyroidism with radioactive iodide (for thyroid cancer), and PTU (helps stop from too much production) -​ Thyroid storm treatment: calcium iodide -​ Parathyroid: in charge of calcium -​ If pt is on synthroid: Check for bruising