Thyroid Pharmacology

Question 1

Tyroid

Answer 1

Regulates metabolism
Production of thyroid hormones
Growth and development

Question 2

Thyroid Hormones

Answer 2

1. Thyroxine (T4)
   * Large pool of T4 found in the circulation.
   * Low turnover rate
2. Tri-iodothyronine (T3)
   * Small pool of T3 found inside the cell.
   * High turnover rate

Question 3

Regulation of thyroid production

Answer 3

Hypothalamus –> TRH —> Pituitary gland–> TSH

(TRH= thyrotrophin releasing hormone)

(TSH= thyroid stimulating hormone)

Question 4

Hyperthyroidism

Answer 4

• Excessive production of thyroid
  hormones.
• High metabolic rate
• Increased temperature & sweating
• Heat sensitivity
• Nervousness
• Tremor
• Increased heart rate
• Muscle twitch
• Weight loss

Question 5

Hypothyroidism

Answer 5

Low production of thyroid hormones
Low metabolism
Weight gain
Decreased heart rate
Cold sensitivity

Question 6

Treating hyperthyroidism

Answer 6

Removing abnormal part of thyroid
Propylthiouracil administration decreases production of thyroid hormones

Question 7

Treating hypothyroidism

Answer 7

No drugs to increase thyroid levels

Replacement therapies
-synthetic forms of T3 (Liothyronine)
-synthetic forms of T4 (levothyroxine)

Adverse effects of these treatments:
Hyperthyroidism
Abnormal heart rates