Thyroid Replacements

Question 1

Common Facts

Answer 1

Commonly used to treat: hypothyroidism (low thyroid)
Common auxiliary labels: take on an empty stomach, take with water
Common dose: 1 tablet once daily, usually first thing in the morning

Question 2

Mechanism of Action

Answer 2

Supplementation of thyroid hormone

Question 3

Notes

Answer 3

T3 has more rapid onset of action & shorter duration of action than T4
T4 has longer onset of action & longer duration of action than T3
Dessicated (armour) thyroid is dried, powdered animal thyroid

Question 4

Warnings

Answer 4

Different manufacturers may have different bioavailability
-Try to keep patients on same brand
Fe (iron) and Ca (calcium) interfere with absorption of thyroid
Food delays with absorption

Question 5

Eltroxin

Answer 5

Generic name: levothyroxine

Tablets: 50mcg, 100mcg, 150mcg, 200mcg, 300mcg

Question 6

Synthroid

Answer 6

Generic name: levothyroxine

Tablets: 25mcg, 50mcg, 75mcg, 88mcg, 100mcg, 112mcg, 125mcg, 137mcg, 150mcg, 175mcg, 200mcg, 300mcg

Question 7

Armour

Answer 7

Generic name: dessicated thyroid

Tablets: 30mg, 60mg, 125mg

Question 8

Cytomel

Answer 8

Generic name: liothyronine

Tablets: 5mcg, 25mcg