Pharmacology Thyroid & Adrenal Disorders

Front 1

What are functions of thyroid hormone?

Back 1

• allows for normal growth and development • maintenance of metabolic balance • affects every organ system

Front 2

What are the two hormones produced by the thyroid gland?

Back 2

T4 (Thyroxine) and T3 (Triiodothyronine)

Front 3

List characteristics of T4

Back 3

• major circulating hormone • highly protein bound (0.03% free) • half life: 7 days

Front 4

List characteristics of T3

Back 4

• produced by peripheral conversion of T4 • less than 20% produced in thyroid • half life: 1.5 days

Front 5

What are some thyroid function tests and what they measure?

Back 5

• Total T3 & T4: measures bound and unbound T4 & T3 • Resin T3 uptake (RT3U): estimates binding capacity of TBG (thyroid binding globulin) • Free T4: measures level of unbound T4 • Radioactive Iodine Uptake (RAIU): measures iodine uptake by thyroid

Front 6

What is the normal range of total T4?

Back 6

4.5-12.5 mcg/dl

Front 7

What is the normal range of total T3?

Back 7

80 - 250 ng/dl

Front 8

What is the normal range of RT3U?

Back 8

22-34%

Front 9

What is the normal range of FT4I (free thyroxine index)?

Back 9

1.0-4.3 units

Front 10

What is the normal range of TSH?

Back 10

0.25-6.7 mIU/L

Front 11

What are causes of hyperthyroidism (thyrotoxicosis)?

Back 11

• autoimmune (Grave's disease) • circulating immunoglobins with TSH-like properties (seen in Myastenia Gravis and in patients receiving IVIG) • exogenous thyroid excess • goiter due to exogenous iodine • tumors • toxic uninodular goiter

Front 12

What are some clinical characteristics of hyperthyroidism?

Back 12

• thyroid enlargement • exopthalmos • pretibial edema

Front 13

What are symptoms of a patient with hyperthyroidism?

Back 13

• fatigue • heat intolerance • loss of weight with increased appetite • nervousness

Front 14

What are physical findings of hyperthyroidism?

Back 14

• warm, smooth, moist skin • thinning hair • onycholysis

Front 15

What drugs can be used to treat hyperthyroidism?

Back 15

thioamides (Methimazole & Propylthiouracil)

Front 16

What is the MOA of the Thioamides (Methimazole & PTU)?

Back 16

• inhibts formation of monoiodotyrosine (MIT) and diiodotyrosine (DIT)
• inhibits coupling of MIT and DIT
• inhibits the oxidation of iodine
• PTU inhibits peripheral conversion of T4 to T3

Hint 16

None

Front 17

What is the dosage for Methimazole?

Back 17

• 15-40 mg daily (initial), then 5-10 mg (maintenance)
• initial dose usually last for 5-7 days

Hint 17

None

Front 18

What are adverse reactions of Methimazole?

Back 18

• Agranulocytosis
• Leukopenia
• LFT changes
• GI
• Rash (usually at the beginning of drug therapy)

Hint 18

None

Front 19

Which drug is more potent, Methimazole or PTU?

Back 19

Methimazole

Front 20

What type of patients is Propylthiouracil (PTU) the drug of choice?

Back 20

• Pregnancy
• Nursing mothers
• Thyroid storm

Hint 20

None

Front 21

What is the dosage of PTU?

Back 21

• Initial: 75-100 mg QID (until symptoms resolve) • Then: 100-150 mg/day in divided doses

Front 22

What are adverse reactions of PTU?

Back 22

• Same as Methimazole (Agranulocytosis, LFT changes, Leukopenia, GI, rash) • also hepatitis

Front 23

What are the 2 types of iodine used to treat hyperthyroidism?

Back 23

• iodine-based solution • radioactive iodine

Front 24

When is an iodine-based solution used?

Back 24

• can be used in an emergent situation (thyroid storm) • can cause rapid progression to euthyroid state

Front 25

What are the 2 iodine-based solutions used?

Back 25

• SSKI (40 mg of iodine per drop) • Lugol's Solution (8 mg/drop)

Front 26

What is the MOA of the iodine-based solutions?

Back 26

• prevents thyroid hormone release • inhibits hormone synthesis

Front 27

What are adverse reactions of iodine-based solutions?

Back 27

• metallic taste • rash

Front 28

What is the MOA of radioactive iodine?

Back 28

• destroys thyroid follicles • effects seen in 3-6 months

Front 29

What type of patients would get radiactive iodine therapy?

Back 29

• patient where drug therapy is ineffective • patient with cardiac disease, elderly • patients with contraindications to drug therapy

Front 30

What type patients would be canidates of surgery to treat hyperthyroidism?

Back 30

• patients with contraindications to drug therapy or RAI • patients with large goiters, malignancy, and obstruction

Front 31

What is the presentation of a patient with acute thyrotoxicosis?

Back 31

• confusion • fever • tachycardia • tremor

Front 32

What is the treatment for acute thyrotoxicosis?

Back 32

• Beta-blockers: to control peripheral and systemic symtoms (ie tachycardia)
• PTU or Iodines: to suppress hormone formation and secretion
• Corticosteroids: to suppress the inflammatory process

Hint 32

None

Front 33

What are causes of hypothyrodism?

Back 33

• Hashimoto's (autoimmune disorder) • Cretinism (in infants) • Hypothalamic disease • Iodine Deficiency • Pituitary Disease • Treatment of hyperthyroidism

Front 34

How do patients with hypothyroidism present clinically?

Back 34

• cold intolerance • fatigue • weakness

Front 35

What are physical findings of hypothyroidism?

Back 35

• coarse skin & hair • thin brittle nails

Front 36

What are the goals of hypothyroidism therapy?

Back 36

• restoration of thyroid hormone concentration • prevent neurologic defects in newborns

Front 37

What is the gold standard of thyroid replacement therapy?

Back 37

• Levothyroxine (Synthroid) • MOA: a synthetic T4

Front 38

What are adverse effects of Levothyroxine (Synthroid)?

Back 38

• sweating • weight loss

Front 39

What are drugs that interact with thyroid replacement therapy?

Back 39

• Bile Acid Sequestrants: decreased thyroid absorption due to binding
• Oral contraceptives/estrogens: increase TBG, resulting in less free thyroid hormone
• Warfarin: increases metabolism of clotting factors (will cause a slight increase in INR)
• Lithium: inhibits release of thyroid hormone

Hint 39

None

Front 40

How would you adjust the dosage of Levothyroxine (Synthroid) with a patient taking oral contraceptives?

Back 40

increase the Levothyroxine (Synthroid) dose

Front 41

What is a Myxedema Coma?

Back 41

• end stage of uncorrected hypothyroidism (an acute medical emergency)

Front 42

What are clinical features of a Myxedema Coma?

Back 42

• Hyponatremia • Hypothermia • Progressive weakness • Stupor

Front 43

What are treatment options for a Myxedema Coma?

Back 43

• Levothyroxine IV • Liothyronine (synthetic T3) • Corticosteroids

Front 44

What are causes of drug-induced thyroid disorders?

Back 44

• Amiodarone
• Antidepressants (Valproic Acids, Atypical Psychotics)
• Iodides
• Lithium

Hint 44

None

Front 45

What are the 2 parts of the adrenal gland?

Back 45

• Cortex (90%) • Medulla (10%)

Front 46

What are the 3 zones of the cortex and what do they secrete?

Back 46

• Zona glomerulosa: aldosterone secretion
• Zona Fasiculata: androgen secretion
• Zona reticularis: cortisol secretion

Hint 46

None

Front 47

What are functions of cortisol?

Back 47

• helps the body respond to stress
• helps maintain blood pressure and cardiovascular function
• helps balance the effects of insulin in breaking down sugar for energy
• helps regulate the metabolism of proteins, carbohydrates, and fats
• helps slow the immune system's inflammatory response

Hint 47

None

Front 48

What class of hormone is aldosterone?

Back 48

mineralcorticoid

Front 49

What is the function of aldosterone?

Back 49

helps maintain blood pressure, water, and salt balance in the body by helping the kidney retain sodium and excrete potassium

Front 50

What is Cushing's syndrome?

Back 50

hyperfunction of adrenal gland

Front 51

What are causes of Cushing's syndrome?

Back 51

• pituitary adenoma • adrenal adenoma • adrenal carcinoma

Front 52

What are clinical features of Cushing syndrome?

Back 52

• moon face, buffulo hump • obesity • HTN • hirsutism • myopathy • menstrual dysfunction

Front 53

What are the 2 ways that Cushing's syndrome is diagnosed?

Back 53

• 24 hr urine free cortisol
• Low dose dexamethasone suppression test: overnight test: 1mg @ 11pm, obtain cortisol level @ 8 am

Hint 53

None

Front 54

What is the treatment for Cushing's syndrome?

Back 54

surgery for adrenal adenoma, carcinoma, and pituitary dependant Cushing's

Front 55

What are the 2 types of hyperaldosteronism?

Back 55

• Primary • Secondary

Front 56

What is the etiology of primary hyperaldosteronism?

Back 56

• aldosterone producing adenoma • idiopathic adrenal hyperplasia

Front 57

What is the presentation of hyperaldosteronism?

Back 57

• HTN • fatigue • nocturia

Front 58

What is the treatment of hyperaldosteronism?

Back 58

• tumor removal • Spirinolactone 200-400 mg QD

Front 59

What are causes of secondary hyperaldosteronism?

Back 59

• diuretics • pregnancy • hemorrhage

Front 60

Which type of diuretics can cause hyperaldosteronism the most?

Back 60

Thiazides

Front 61

What is the treatment of secondary hyperaldosteronism?

Back 61

removal of the source

Front 62

What hypertension drug class would you use for a patient with HTN and hyperaldosteronism?

Back 62

ACE inhibitor because by blocking conversion to angiotensin II you also block aldosterone

Front 63

What are the 2 types of adrenal insufficiency?

Back 63

• Primary (Addison's disease) • Secondary

Front 64

What are causes of primary adrenal insufficiency (Addison's disease)?

Back 64

• destruction of the adrenal cortex (autoimmune, TB, AIDS, Sepsis)

Front 65

What is a cause of secondary adrenal insufficiency?

Back 65

excessive use of glucocorticoids

Hint 65

None

Front 66

How do patients with adrenal insufficiency clinically present?

Back 66

• dehydration
• decreased sodium
• hypotension
• hypoglycemic
• increased potassium
• weight loss

Hint 66

None

Front 67

What is the treatment of adrenal insufficiency?

Back 67

lifetime corticosteroid replacement

Front 68

What does Fludrocortisone prevent in patients with Addison's disease?

Back 68

hyperkalemia

Front 69

What is the treatment for acute adrenal insufficiency?

Back 69

• Hydrocortisone 100 mg IV Q6hrs for the first 24 hrs
• then Hydrocortisone 50 mg IM (or IV) Q 6hrs
• Hydrocortisone 40 mg PO Q AM and 20 mg PO q pm

Hint 69

None

Front 70

What is the drug and dosing for chronic adrenal insufficiency?

Back 70

• require hydrocortisone (Cortef) twice a day and Florinef (Fludrocortisone)
• Fludrocortisone: 0.05-0.2 mg PO Q24

Hint 70

None

Front 71

Why is fludrocortisone usually given for adrenal insufficiency?

Back 71

to replace aldosterone which controls sodium and potassium to keep blood pressure normal

Front 72

__ mg of Cortisone = __ mg of Hydrocortisone = __ mg of Prednisone = __ mg of Methylprednisolone = __ mg of Dezamethasone

Back 72

25 mg of Cortisone = 20 mg of Hydrocortisone = 5 mg of Prednisone = 4 mg of Methylprednisolone = 0.75 mg of Dezamethasone

Front 73

Which corticosteroids are only available PO?

Back 73

Cortisone and Prednisone

Front 74

Which corticosteroids are available PO and IV?

Back 74

• Hydrocortisone • Methylprednisolone • Dezamethasone

Front 75

Which corticosteroid has the longest duration (is the most long-acting)?

Back 75

Dexamethasone

Front 76

What are uses of corticosteroids?

Back 76

• replacement therapy
• anti-inflammatory and immune suppression
• arthritis, asthma, allergies, dermatologic conditions

Hint 76

None

Front 77

What are adverse effects of corticosteroids?

Back 77

• decreased immune system
• diabetes
• edema
• HTN
• Hypocalcemia
• thinning of skin
• PUD

Hint 77

None