Hormonal Drugs Affecting the Thyroid and Calcium Balance

 

Introduction to Hormonal Regulation

“The Symphony of Hormones”

Picture the body as an orchestra. The hypothalamus is the conductor, the pituitary is the lead violinist, and the thyroid and parathyroid glands are key instrumentalists managing tempo and pitch (metabolism & calcium levels).

Key Objective: Learn how these hormones and drugs work in harmony (or conflict).

Hypothalamic and Pituitary Hormones, Parathormone, Calcitonin, Vitamin D

Hypothalamic and Pituitary Hormones

 “Command Center: Hypothalamus and Pituitary”

  • Hypothalamus CRH, TRH, GnRH, GHRH, Somatostatin
  • Pituitary ACTH, TSH, LH/FSH, GH, Prolactin

 Function:

  • TSH: Stimulates thyroid to produce T3/T4.
  • ACTH: Adrenal cortisol release.
  • Mini-Story: Imagine the hypothalamus sending emails (hormones) to pituitary, which then broadcasts the message (secondary hormones) to peripheral glands.

Parathyroid Hormone (PTH) (“Bone Banker: The Role of PTH”)

Functions:

  • ↑ Blood calcium by bone resorption
  • ↑ Renal Ca²⁺ reabsorption
  • Activates vitamin D (calcitriol)

 Cartoon of PTH knocking on bones saying “Give me calcium!”

Calcitonin (“The Peacekeeper”)

Functions:

  • ↓ Blood calcium
  • Inhibits osteoclasts
  • Released from thyroid C-cells

Therapeutic Use: Paget’s disease, hypercalcemia

Cartoon of calcitonin calming a riot (osteoclasts).

 

Vitamin D  (“The Sunshine Hormone”)

Pathway:
Sunlight
Cholecalciferol (skin) Calcidiol (liver) Calcitriol (kidney) Enhances Ca²⁺ absorption

Uses: Rickets, osteoporosis, hypocalcemia

“Mr. D” travels from the beach (skin) to the library (liver), then to a lab (kidney), finally helping children build strong bones!

Thyroid Hormones

Thyroid Hormones – The Metabolic Spark (“T3 & T4: The Fire Starters”)

List of Hormones:

  • T4 (Thyroxine): prohormone
  • T3 (Triiodothyronine): active form

Functions:

  • ↑ BMR
  • ↑ protein synthesis
  • CNS development
  • Sympathetic stimulation

T3 and T4 as energetic twins lighting up the body's metabolic fire.

Anti-thyroid Drugs

Classification of Anti-Thyroid Drugs (“Cooling the Thyroid Furnace”)

Classification:

  1. Antithyroid drugs (thioamides): Propylthiouracil (PTU), Carbimazole
  2. Ionic inhibitors: Thiocyanates, Perchlorates, Nitrates
  3. Hormone release inhibitors: Iodine, NaI, KI
  4. Destructive agents: Radioactive iodine (¹³¹I)

Toolbox of a technician repairing an overheated furnace.

1. Thioamides – Propylthiouracil & Carbimazole (“Taming the Enzyme”)

Mechanism: Inhibit thyroid peroxidase, blocking:

  • Iodination of tyrosine
  • Coupling of iodotyrosines

Propylthiouracil also inhibits peripheral conversion of T4 to T3.

Uses: Hyperthyroidism, Grave’s disease

Adverse Effects: Agranulocytosis, hepatotoxicity, rash

Interactions: Potentiates anticoagulants, decreases efficacy of β-blockers

2. Ionic Inhibitors (“Sneaky Ions Block the Gate”)

Drugs: Thiocyanate, Perchlorate, Nitrate

Mechanism: Block iodine uptake into thyroid by inhibiting Na⁺/I⁻ symporter

Risk: Aplastic anemia, goiter

Cartoon of ions clogging the thyroid's iodine pipeline.

3. Iodine and Iodides (NaI, KI) (“Too Much of a Good Thing”)

 Wolff–Chaikoff effect: High iodine levels transiently inhibit thyroid hormone release.

Uses: Thyroid storm, pre-op preparation

Adverse Effect: Iodism (metallic taste, sore teeth/gums)

 Iodine acting like a bouncer at a hormone party – temporarily blocking entry.

4. Radioactive Iodine (¹³¹I, ¹²⁵I, ¹²³I) (“The Silent Assassin”)

Mechanism: Beta-emission destroys overactive thyroid cells

Use: Definitive treatment for hyperthyroidism, thyroid carcinoma

Contraindicated in: Pregnancy, breastfeeding

  Stealth drone (¹³¹I) targeting and disabling thyroid overgrowth.

Interactive Case Study

“Meet Rina – A Case of Sweating, Anxiety, and Weight Loss”

Symptoms: Rina presents with tremor, weight loss, sweating. Labs show ↑ T3/T4, ↓ TSH.

Question: What’s the diagnosis? Which drug to start with? Risks?

                     END OF THE TOPIC

SHARE

Owner

Hi. I’m Writer of Researchsop.com. ’ ’ Please share these SOPs to all concern pharma people for their development. I like to fullfill the need of curious people. These things inspire me to make things looks better.

  • Image
  • Image
  • Image
  • Image
  • Image
    Blogger Comment
    Facebook Comment

0 comments:

Post a Comment