Thyroid

Question 1

Triiodothyronine

Answer 1

T3 (3 iodine atoms)

-More potent than T4, but shorter half life

Question 2

Thyroxine

Answer 2

T4 (4 iodine atoms)

-Broken down into T3

Question 3

Drugs that Cause HYPOthyroidism

Answer 3

ITALC

• Interferons**
• Tyrosine Kinase Inhibitors
• Amiodarone**
• Lithium
• Carbamazepine

Conditions: Hashimoto’s Disease

Question 4

S/Sxs of HYPOthyroidism

Answer 4

• Cold intolerance/sensitivity
• Dry skin
• Fatigue
• Muscle cramps/myalgias/weakness
• Weight gain
• Goiter
• Bradycardia
• Constipation
• Menorrhagia (heavier periods)

Question 5

Levoxyl

Answer 5

• Levothyroxine (T4) - AKA Synthroid and Unithroid
• Drug of choice for hypothyroidism (constant preparation)
• Full replacement dose = 1.6 mcg/kg/d (IBW)
• If known CAD, start at 12.5-25 mcg/d
• IV:PO is 0.75:1
• Monitor TSH levels/clinical sxs Q4-6w until normalized
• Safe in pregnancy but may need to increase maintenance dose by 30-50% throughout preggo course

Question 6

Armour Thyroid

Answer 6

-Thyroid, desiccated (T3 and T4)

Question 7

Cytomel

Answer 7

• Liothyronine (T3)

- Shorter half life!

Question 8

Levothyroxine Tablet Colors

Answer 8

Orangutans Will Vomit On You Right Before They Become Large, Proud Giants
Orange = 25 mcg
White (no dye) = 50 mcg
Violet = 75 mcg
Olive = 88 mcg
Yellow = 100 mcg
Rose = 112 mcg
Brown = 125 mcg
Turquoise = 137 mcg
Blue = 150 mcg
Lilac = 175 mcg
Pink = 200 mcg
Green = 300 mcg

Question 9

Drugs that cause HYPERthyroidism

Answer 9

• Iodine (radiocontrast dye)
• Amiodarone**
• Interferons**

Condition: Grave’s Disease

Question 10

S/Sxs of HYPERthyroidism

Answer 10

• Heat intolerance/increased sweating
• Weight loss
• Agitation/anxiety
• Palpitations/tachycardia
• Insomnia
• Tremor
• Fatigue/muscle weakness
• Frequent bowel movements/diarrhea
• Light/absent menstruation
• Protruding eyeballs (exophthalmos)

B-blockers can help control sxs

Question 11

PTU

Answer 11

• Propylthiouracil
• Thionamide: inhibits synthesis of thyroid hormones and stops peripheral conversion of T4 to T3
• Box warning: severe liver injury and acute failure
• Preferred agent for 1st trimester
• Preferred for thyroid storms

Question 12

Tapazole

Answer 12

• Methimazole
• Thionamide: inhibits synthesis of thyroid hormones and stops peripheral conversion of T4 to T3
• Drug of choice in 2nd and 3rd trimesters
• Generally speaking the drug of choice over PTU except in situations mentioned on card

Question 13

Thionamide Information

Answer 13

• Warning: hepatotoxic, DILE drugs, agranulocytosis (rare)

- SE: GI upset

Question 14

S/Sxs of Thyroid Storm

Answer 14

• Fever (>103 F)
• Tachycardia/tachypnea
• Dehydration
• Profuse sweating
• Agitation
• Delirium/psychosis
• Coma

Question 15

Thyroid Storm Tx

Answer 15

1. Antithyroid therapy - PTU preferred
2. Inorganic iodine therapy - SSKI or Lugol’s solution
3. B-blocker - propranolol preferred
4. Systemic Steroid - dexamethasone
5. Aggressive cooling- APAP and cooling blankets