Hormones are chemical substances produced by endocrine glands and certain nerve cells that act on specific target tissues to affect physiological functions. There are two main types of hormones: lipid soluble and water soluble. The thyroid gland, located in the neck, secretes thyroid hormones thyroxine and calcitonin which regulate metabolism and growth. Thyroid hormones are synthesized through a multi-step process and their production is controlled by the hypothalamus and pituitary gland through feedback loops. Abnormal thyroid function can lead to diseases like hypothyroidism, hyperthyroidism, and thyroiditis.

1. Clinical Pharmacy: Pharmacology and Pharmcotherapeutics
TOPIC OF INTEREST: HORMONES
Mrs.Rishita Darshan Patel
(M.Pharm, Clinical Pharmacy)

2. HORMONES
By Nature They Are Amines, peptides/Proteins, cholesterol
• Hormones are chemical substances produced by endocrine glands and certain nerve cells.
They are carried through blood through out the body
Act on specific target tissues and organ
And affect various physiological function
of body
Produced response such as
growth of body, metabolism,
regulation of reabsorption
Balancing internal
homeostatic
M/A

3. It Is Also Called As Neuroendocrine System
• This two system function to gather and make a “super system”
• Because it not only includes the glands but also includes certain parts of
nervous system which stimulate or inhibit the release of the endocrine
system.

4. Basic Difference Between Nervous System And Endocrine System
Nervous system Endocrine system
Mediator molecules are
neurotransmitters.
Mediator molecules are hormones.
Synapse is site of mediator action. site of mediator action is very far
from endocrine cells.
Muscles are most prominent target
cells.
Cells of body is prominent target
cells.
Work within milliseconds. Works within seconds to hours/days.
Short duration of action. Longer duration of action.

5. Hormones Are Of Two Types
1.Lipid Soluble 2. Water Soluble

6. Water Soluble Hormones
[Amine (Histamine, serotonin),Protein Hormones]

7. Major Endocrine Glands

8. Thyroid Gland
• Member of the Endocrine System
• Secretes thyroid hormones, thyroxine and calcitonin, which regulate metabolism
and growth.
• Located in neck adjacent to the 5th cervical vertebra (C5).
• Composed of epithelial cells which specialize in the absorption of iodine and, of
course, secretion of thyroid hormones.

9. • The thyroid is made up of lobules containing a series of follicles.
• The lumen of each follicle is surrounded by a single layer of epithelial cells, called
follicular cells, and the lumen filled with a pink-staining (with hematoxylin and
eosin dye ) proteinacious material, called colloid.
• The follicular cells synthesize thyroglobulin, thyroid hormone precursor, which is
extruded into the lumen of the follicle for storage.

10. The Two Principal Thyroid Hormones Are
1. Thyroxine (T4 Or L-3,5,3',5'-tetraiodothyronine)
2.Triiodotyronine (T3 Or L-3,5,3'-triiodothyronine)
• The Thyroid hormones are basically two tyroxine linked together with the critical addition of iodine at three or
four positions on the aromatic rings. The number and position of the iodines is important.
• Thyroid hormones are poorly soluble in water, and more than 99% of the T3 and T4 circulating in blood is
bound to carrier proteins.
• The principle carrier of thyroid hormones is thyroxine-binding globulin, a glycoprotein synthesized in the liver.
• It allows stable pool of thyroid hormones from which the active, free hormones are released for uptake by target
cells.

11. Stages Of Synthesis Of Thyroid Hormones
Synthesis of thyroid hormones occurs in five stages:
• Thyroglobulin synthesis
• Iodide trapping
• Oxidation of iodide
• Transport of iodine into follicular cavity
• Iodination of tyrosine
• Coupling reactions.

13. Control Of Thyroid Hormone Production

14. Pharmacological Action Of Thyroid Hormone
• Calorigenic (increased oxygen consumption) action and controls BMR.
• Increased carbohydrate and protein metabolism.
• Increased cholesterol turnover (hypolipidaemic effects).
• Increased heart rate, contractility and cardiac output.
• Increased calcium mobilization from bone.
• Effect on Sympathetic Nervous System.
• Regulation of water and electrolyte balance.
• Essential for normal body growth,development and reproduction.

15. Diseases Associated With The Abnormal Thyroid
• Hypothyroidism in Adults
• Hypothyroidism in Children (Cretinism)
• Thyroiditis
• Hyperthyroidism
• Grave's Disease/ Toxic goiter : also known as toxic diffuse goiter, is an autoimmune
disease that affects the thyroid. It is the most common cause of hyperthyroidism. It also
often results in an enlarged thyroid.
• Plummer's Syndrome is a toxic multinodular goiter due to overproduction of thyroid
hormone.
• Hashimoto's thyroiditis involved abnormal T cell activation and subsequent B cell
stimulation to secrete a variety of auto-antibodies and gradually destroy thyroid glands.

17. Thyroid Medication

19. Antithyroid Drug classification

20. Diagnosis Of Hyperthyroidism