Hyperthyroidism medications Notes

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Osmosis High-Yield Notes

This Osmosis High-Yield Note provides an overview of Hyperthyroidism medications essentials. All Osmosis Notes are clearly laid-out and contain striking images, tables, and diagrams to help visual learners understand complex topics quickly and efficiently. Find more information about Hyperthyroidism medications by visiting the associated Learn Page.
NOTES NOTES HYPERTHYROIDISM MEDICATIONS Figure 1.1 Sodium iodide 131I: mechanism of action. WHAT ARE THEY? Basic information ▪ Drugs used to control hyperthyroidism, symptoms Mechanism of action ▪ Sodium iodide 131I: iodine isotope absorbed by thyroid gland → beta radiation destroys thyroid tissue (partial ablation) → ↓ thyroid hormone synthesis ▪ MethIMAzole, propylthiouracil: absorbed by thyroid gland → blocks thyroid peroxidase → inhibits iodide oxidation, iodination, and coupling of MIT (monoiodotyrosine) and DIT (diiodotyrosine) → ↓ thyroxine (T4) and triiodothyronine (T3) synthesis ▫ Propylthiouracil inhibits 5’- deiodinase → ↓ peripheral T4 → T3 conversion ▪ Potassium iodide; potassium iodide + iodine: ↓ iodine uptake by thyroid, thyroid hormone synthesis and secretion; ↓ thyroid size, vascularity ▪ Propranolol: blocks beta receptors → ↓ sympathetic symptoms; blocks 5’deiodinase → ↓ conversion of T4 into T3 TYPES ▪ Sodium iodide 131I (Hicon): PO ▪ MethIMAzole (Tapazole); propylthiouracil: PO ▪ Potassium iodide (saturated potassium iodide solution) (SKKI, Thyroshield): PO ▪ Potassium iodide + iodine (Lugol’s solution): PO ▫ 10% potassium iodide, 5% iodine ▪ Beta blockers (e.g. propranolol): PO, IV Common indications ▪ Graves’ disease, hyperthyroidism, thyroid storm, toxic multinodular goiter ▫ Sodium iodide 131I: thyroid ablation (definitive treatment) ▫ Potassium iodide; potassium iodide + iodine: thyroidectomy preparation; not for long-term therapy (thyroid adapts, resumes thyroid hormone synthesis after few weeks) OSMOSIS.ORG 1
CLINICAL CONCERNS ADVERSE EFFECTS ▪ Hypothyroidism ▪ Dermatologic reactions (e.g. rash, pruritus, toxic epidermal necrolysis) Drug-specific adverse effects ▪ Sodium iodide 131I ▫ Infertility; thyroiditis; radiation toxicity (e.g. neoplasia, hematopoietic suppression, salivary and lacrimal gland toxicity) ▪ MethIMAzole, propylthiouracil ▫ Vasculitis ▫ Lupus-like syndrome ▫ Agranulocytosis; hypoprothrombinemia → infections; bleeding ▫ Hepatotoxicity (propylthiouracil > methIMAzole) ▪ Potassium iodide + iodine ▫ Drug fever ▫ Metallic taste ▫ Bleeding disorders ▫ Anaphylactic reactions (rare) COMMON DISEASE-RELATED CONCERNS ▪ Sodium iodide 131I: not recommended in active, moderate–severe Graves ophthalmopathy Figure 1.2 Potassium iodide: mechanism of action. 2 OSMOSIS.ORG ADMINISTRATION ▪ Sodium iodide 131I ▫ Pre-administration: negative pregnancy test required for childbearing individuals ▪ Potassium iodide ▫ Administer with food/diluted with fluids (↓ gastric irritation) PREGNANCY/BREASTFEEDING IMPLICATIONS ▪ Boxed warning: propylthiouracil → use during first trimester only ▪ MethIMAzole: preferred agent during second/third trimesters, breastfeeding CONTRAINDICATIONS ▪ Sodium iodide 131I: during pregnancy/ breastfeeding ▪ MethIMAzole: during first trimester of pregnancy; teratogenic (aplasia cutis) ▪ Potassium iodide, potassium iodide + iodine: during pregnancy/breastfeeding (hypothyroidism, fetal goiter) ▪ Sodium iodide 131I: people who are/may become pregnant, breastfeeding
Endocrine Hyperthyroidism Medications Figure 1.3 Methimazole and propylthiouracil: mechanism of action. Figure 1.4 Propranolol: mechanism of action. OSMOSIS.ORG 3
Figure 1.5 Hyperthyroidism medications: Common drug-drug interactions. 4 OSMOSIS.ORG
Endocrine Hyperthyroidism Medications Figure 1.6 Hyperthyroidism medications: general adult dosing guidelines (1). *Dosage varies depending on dosing interval, individual characteristics. OSMOSIS.ORG 5
Figure 1.7 Hyperthyroidism medications: general adult dosing guidelines (1). *Dosage varies depending on dosing interval, individual characteristics. 6 OSMOSIS.ORG

Osmosis High-Yield Notes

This Osmosis High-Yield Note provides an overview of Hyperthyroidism medications essentials. All Osmosis Notes are clearly laid-out and contain striking images, tables, and diagrams to help visual learners understand complex topics quickly and efficiently. Find more information about Hyperthyroidism medications by visiting the associated Learn Page.