B / 17 : Thyroid And Antithyroid Drugs. Pituitary Hormones. Hypothalamic Hormones, Hormone Analogs & Antagonists

Question 1

Hypothyroidism
- Cause
- Symptoms
- Therapy

Answer 1

• Iodine decrease (autoimmune, infection, tumor)
• Weakness, tiredness, hair loss, cold body, hypercholesterolemia
• Hormone supplementation

Question 2

Hyperthyroidism
- Cause
- Symptoms (6)
- Therapy

Answer 2

• Adenoma, Graves disease
• Increased metabolism, weight loss, increased appetite, heat sensitivity, tachycardia, high BP
• Thioamide therapy

Question 3

What are the thyroid preparations?

Answer 3

• Levothyroxine (T4)
• Iodine

Question 4

Levothyroxine (T4)
- MOA
- Effect
- Indication
- SE
- Extra
- ROA

Answer 4

• Synthetic thyroxine
• Increased metabolism, increased body temperature
• For hypothyroidism management
• Symptoms of hyperthyroidism, osteoporosis in long-term
• Converted to T3 in target cells, liver, kidneys
• Oral

Question 5

Dose of Levothyroxine

Answer 5

25-150 micrograms

Question 6

Iodine
- MOA
- Indication
- ROA

Answer 6

• Inhibit thyroid hormone release
• For thyroid storm / preparation for surgical thyroidectomy
• Oral

Question 7

What are the anti thyroid drugs?

Answer 7

• Propylthiouracil (PTU)
• Thiamazole

Question 8

Propylthiouracil, thiamazole
- MOA
- Effect
- Indication
- SE
- ROA

Answer 8

• Inhibit thyroid peroxydase activity (+ Deiodinase enzyme for PTU)
• No new thyroid hormone production
• For hyperthyroidism
• Vasculitis, drug-induced lupus, hepatotoxicity
• Oral

Question 9

What are the hypothalamic regulators of anterior pituitary hormones

Answer 9

• Octreotide
• Bromocriptine

Question 10

Octreotide
- MOA
- Effect
- Indication
- SE
- ROA

Answer 10

• Somatostatin analog
• Inhibits release of GH, insulin, glucagon, gastrin + decrease GI function
• For acromegaly (pituitary adenoma), gigantism, acute GI hemorrhage
• GI side effects
• Parenteral

Question 11

Bromocriptine
- MOA
- Effect
- Indication
- SE
- ROA

Answer 11

• D2 dopamine receptor AGonist
• Suppresses pituitary secretion of prolactin and GH : adenoma regression
• For hyperprolactinemia, prolactinoma, acromegaly, infertility
• Psychiatric disturbances, GI, peripheral vasoconstriction
• Oral

Question 12

How does Bromocriptine suppress pituitary secretion?

Answer 12

It binds to D2, which is Gi coupled -> inhibition of adenyl cyclase -> decreased calcium -> negative regulation of prolactin hormone secretion

Question 13

What are the regulators of posterior pituitary hormones?

Answer 13

• Oxytocin
• Desmopressin

Question 14

Oxytocin
- MOA
- Indication
- SE
- ROA

Answer 14

• Gq coupled : SM contraction -> induces uterine contraction
• Induction and augmentation of labor, decrease postpartum hemorrhage, induction of lactation
• Fetal distress, placental abruption, uterine rupture, HF
• IV, intranasal

Question 15

Desmopressin
- MOA
- Effect
- Indication
- SE
- ROA

Answer 15

• ADH agonist (V2 selective)
• Translocation of aquaporins : increased water reabsorption
• For central diabetes, nocturnal enuresis, hemophilia A
• GI disturbances, hyponatremia, allergic reaction
• IV, intranasal, oral, subcutaneous