chemistry of thyroid treatments

Question 1

thyroid chemistry

Answer 1

• thyroid gland converts tyrosine to monoiodotyrosine (MIT) and diiodotyrosine (DIT)
• thyroid stimulating (TSH) and releasing hormones (TRH) acts as a system to regulate production of T3/T4
• MIT + DIT > T3
• DIT + DIT > T4

Question 2

levothyroxine chemistry

Answer 2

logP 7.4
pKa 10/9/4

Question 3

liothyronine chemistry

Answer 3

logP 6
pKa 10/9/4

Question 4

carbimazole

Answer 4

• prodrug
• logP 0.3

Question 5

methimazole

Answer 5

• active methimazole inhibits thyroid peroxidases which convert tyrosine in to MIT and DIT

Question 6

propylthiouracil

Answer 6

• inhibits thyroid peroxidases which convert tyrosine in to MIT and DIT
• also inhibits 5’-deionase enzymes helping T3 biosynthesis
• logP 0.4