Thyroid Flashcards
Thyroid hormone effects
- Metabolism
- Cardiac function
- Growth (infants and kids)
- Development
TSH
Screening and dx of hypothyroidism
Elevated tsh
Hypothyroidism
Hypothyroidism clinical presentation
Pale, puffy face ➢Cold, dry skin ➢Brittle hair or loss of hair ➢Lowered heart rate and temperature ➢Lethargy and fatigue ➢Intolerance to cold ➢Impaired mentality
Hypothyroidism causes
➢Usually due to malfunction of the thyroid
➢Hashimoto disease: Chronic autoimmune thyroiditis
➢Insufficient iodine in the diet
➢Surgical removal of thyroid and destruction of thyroid with radioactive iodine
➢Insufficient secretion of TSH and thyrotropin-releasing hormone (TRH)
Hyperthyroidism cause
Thyroid-stimulating immunoglobulins (TSIs)
Hyperthyroidism tx
Surgical removal of thyroid tissue ➢Destruction of thyroid tissue ➢Suppression of thyroid hormone synthesis ➢Beta blockers (e.g., propranolol) ➢Nonradioactive iodine
Levothyroxine
Synthetic preparation of thyroxine (T4) and drug of choice for hypothyroidism
➢Conversion to T3
Levothyroxine half life
7 days
Levothyroxine AE
Tachycardia
•Angina
•Tremors
•Can intensify effects of warfarin
Levothyroxine drug interactions
Drugs that reduce levothyroxine absorption
•Drugs that accelerate levothyroxine metabolism
•Warfarin
•Catecholamines
Methimazole
Hyperthyroidism
Does not cause liver damage associated with ptu
Agranulocytosis
More dangerous than PTU during lactation and during the first trimester of pregnancy
Levothyroxine euthyroid state
Takes 3-12 weeks
Methimazole uses
Sole form of therapy for Graves disease
➢Adjunct to radiation therapy until the effects of radiation become manifest
➢Suppresses thyroid hormone synthesis in preparation for thyroid gland surgery (subtotal thyroidectomy)
➢Thyrotoxic crisis
Propylthiouracil inhibits
Thyroid hormone synthesis
Propylthiouracil half life
90 minutes
Ptu uses
➢Graves disease
➢Adjunct to radiation therapy
➢Preparation for thyroid gland surgery
➢Thyrotoxic crisis
Ptu AE
Agranulocytosis (most serious)
➢Hypothyroidism
➢Pregnancy and lactation
➢Can cause severe liver damage
Low T3 and t4
Hypothyroidism
Low tsh
Hyperthyroidism
High t3 and t4
Hyperthyroidism
If you don’t see regular problem with tsh, t3, t4
Secondary problem with hypothalamus or anterior pituitary
Triiodothyronine
T3
Thyroxine
T4