Drugs for Thyroid Disorders

Question 1

Thyroid Hormones

Answer 1

t4 - thyroxine
t3 - triodythronine
calcitonine
TSH

Question 2

Hypothyroidism

Answer 2

• severe deficiency of thyroid hormone (Myxedema in adults, cretinism in infants)
• increase in TSH and decrease in T3 and T4 (increase in TSH because trying to compensate for low T3 and T4 levels)
• clinical presentation shows pale puffy and expressionless face, cold and dry skin, brittle hair or loss of hair, HR and temp lowered, lethargy and fatigue, intolerance to cold, and impaired mentality

Question 3

2 types of hyperthyroidism

Answer 3

• grave’s disease (most common, affects women from 20-40, causese exophthalmos)

toxic nodular goiter (Plummer’s disease)

Question 4

Signs and symptoms of Thyrotoxic Crisis

Answer 4

• hyperthermia
• severe tachycardia
• restlessness, agitation
• tremor
• unconsciousness
• coma
• hypotension
• heart failure

Question 5

Levothyroxine (synthroid)

Answer 5

• synthetic preparation of thyroxine (T4) and drug of choice for hypothyroidism
• conversion to t 3
• half life is 7 days
• used for all forms of hypothyroidism
• should be taken in the morning at least 30 to 60 min before breakfast
• adverse affects include tachycardia, angina, tremors, and can intensify effects of warfarin
• interacts with drugs that reduce levothyroxine absorption, drugs that acccelerate levothyroxine metbolism, warfarin, and catecholamines

Question 6

Hyperthyroidism

Answer 6

• hyperactive thyroid
• indicated by high levels of T3 and T4
• treated by destruction or removal of thyroid tissue, or suppression of thyroid hormone synthesis

Question 7

Methimazole

Answer 7

• first line hyperthyroidism drug
• prototype thionamides
• causes no liver damage, does not destroy existing TH stores, can take 3-12 weeks for a euthyroid state
• dangerous to use during pregnancy
• only therapy for grave’s disease
• used along side radiation therapy, before thyroid surgery,, and for patients experiencing thyrotoxic crisis

Question 8

Propylthiouracil (PTU)

Answer 8

• inhibits thryroid hormone synthesis
• second line for grave’s disease
• short half life
• full benefits can take 6-12 months
• therapeutic uses include graves diseas, alongside radiation therapy, in preperation for thyroid surgery , and for thyrotoxic crisis (preferred)
• adverse effects include agranulocytosis, hypothyroidism, pregancy and lactation, can cause liver damage
• preferred drug for pregnancy

Question 9

PTU vs Methimazole

Answer 9

• PTU cause severe liver damage
• PTU shorter half life, requires more doses
• PTU crosses placenta less readily, drug of choice for pregnancy
• PTU blocks conversion of T4 to T3, methimazole doesnt

Question 10

Radioactive Iodine 131

Answer 10

• used in thyroid cancer, graves disease, diagnostics , and preparations

Question 11

Nonradioactive Iodine

Answer 11

• lugol’s solution
• used to suppress thyroid function in preparation for thyroidectomy
• adverse effects include brassy taste, burning in mouth and throat, sore teeth and gums, headache, coryza, salivation, and skin eruptions

Question 12

Beta Blockers

Answer 12

• suppresses tachycardia and other symptoms of graves disease
• beneficial in thyrotixic crisis

Question 13

Thyroid testing

Answer 13

• test for TSH, T3, and T4 levels

- Low T3 and T4 and high TSH signifies hypothyroidism, while High T3 and T4 signifies hyperthyroidism