module 16 hypothyroid meds

Question 1

levothyroxine MOA

Answer 1

L-isomer of T4

- body converts to T3 as needed

Question 2

levothyroxine AE

Answer 2

s/s of hyperthyroidism: dose too high

allergic reaction

Question 3

levothyroxine admin

Answer 3

long half life: 6-7 days

• daily dosing
  prodrug: converted to T3

Question 4

levothyroxine DI inc. levothyroxine metabolism

Answer 4

phenobarbital
phenytoin
rifampin
carbamazapine

Question 5

levothyroxine DI dec. T4 to T3 conversion

Answer 5

PTU
B-blockers
amiodarone
glucocorticoids

Question 6

levothyroxine DI dec. absorption of levothyroxine in gut

Answer 6

cholestyramine
FeSO4
Al(OH)3
sucuralfate
Na polystyrene sulfonate

Question 7

levothyroxine DI inc. T3 and T4 binding

Answer 7

pregnancy

estrogen

Question 8

levothyroxine monitoring

Answer 8

TSH

T4

Question 9

cytomel MOA

Answer 9

T3 analong

Question 10

cytomel use

Answer 10

life-threatening hypothyroidism

- myxedema coma

Question 11

cytomel admin

Answer 11

short half life: 1 day

Question 12

amiodarone and thyroid status

Answer 12

structurally resembles thyroid hormone
contains large amounts of iodine
-> hyper/hypothyroidism

Question 13

lithium and thyroid status

Answer 13

actively concentrated in thyroid gland
body thinks it is iodine
-> inhibit thyroid synthesis -> hypothyroidism

Question 14

metoclopramide and thyroid status

Answer 14

increases TSH production/release

-> hyperthyroidism