Thyroid drugs

Question 0

Liothyronine sodium

Answer 0

Cytomel
T3, shorter T1/2 & duration of action of T4
Used for initial/rapid hypothyroidism tx (not for maintenance)
Cardiotoxic w/ sympathetics, potentiates warfarin, change dose in DM drugs.

Question 1

Levothyroxine sodium

Answer 1

Synthroid
T4
DOC for hypothyroidism (->nl levels of T3, T4)
Titrate drug levels to pt: TSH levels, pt ssx
Cardiotoxic w/ sympathetics, potentiates warfarin, int w/ DM tx& ccsteroids

Question 2

Propylthiouracil

Methimazole

Answer 2

Thioamides- for hyperthyroidism, Graves.
Methimazole DOC, dec synth of T4, inc potency than PTU
Granulocytosis and agranulocytosis risk
Use before surgery to dec risk of thyroid storm

Question 3

Propylthiouracil

Answer 3

Thioamide, for hyperthyroidism, Graves
blocks conversion of T4 to T3,
black box warning: liver failure (use only if pregnant)
Granulocytosis and agranulocytosis risk
Use before sx to dec risk of thyroid storm.

Question 4

Iodine

Answer 4

Rapidly dec synth/release of T4/T3, short term effect (2-8wks)
Dec vascularity & thyroid in gland, use for 7-10d before surgery (dec risk of thyroid storm)
Use in radioactive emergencies (competes for iodine)

Question 5

Radioactive iodine

Answer 5

Taken into gland specifically, use in elderly and heart disease
microC: diagnostic, mmC: destroys gland (adjunct or instead of sx)
Adverse: hypothyroidism over time, thyroid stomr risk (dec by using thioamide prior to tx.

Question 6

Propanolol

Answer 6

Inderal - Bblocker, dec many (masks) of ssx of hyperthyroidism
Used to prepare for sx