Thyroid Pharmacology: Drugs, Functions, and Disorders

What hormones does the thyroid gland produce?

T4 (Thyroxine), T3 (Triiodothyronine), and Calcitonin.

What is the function of Calcitonin?

Helps regulate calcium levels.

What are the primary functions of T3 and T4?

Control cellular metabolism, heart function, skeletal muscle activity, liver and kidney function, brain function, sleep, and reproductive function.

What is hyperthyroidism?

A condition characterized by too much thyroid hormone.

What is a common cause of hyperthyroidism?

Graves Disease.

What is a life-threatening complication of hyperthyroidism?

Thyroid Storm.

What are the symptoms of Thyroid Storm?

Tachycardia, fever, dehydration, heart failure, and coma.

What is hypothyroidism?

A condition characterized by too little thyroid hormone.

What is the most common thyroid disorder?

Hypothyroidism, especially in women over age 50.

What is Myxedema?

Severe adult hypothyroidism characterized by a hypometabolic state and non-pitting edema.

What is a life-threatening complication of hypothyroidism?

Myxedema Coma.

What are the symptoms of Myxedema Coma?

Coma, hypothermia, cardiovascular collapse, and hypoventilation.

What are Thionamides used for?

To treat hyperthyroidism.

Name two examples of Thionamides.

Propylthiouracil (PTU) and Methimazole (Tapazole).

What is the mechanism of action of Thionamides?

They inhibit thyroid hormone synthesis, reducing the production of T3 and T4.

What is a significant risk associated with Thionamides?

Severe liver injury, including acute liver failure.

What is Radioactive Iodine Therapy used for?

To treat hyperthyroidism and thyroid cancer.

What is the mechanism of Radioactive Iodine?

It is absorbed by the thyroid, destroying overactive thyroid tissue and decreasing hormone production.

What are the possible adverse effects of Radioactive Iodine?

Hypothyroidism, rash, goiter, and salivary gland swelling.

What is Levothyroxine used for?

To treat hypothyroidism, thyroid cancer, and myxedema coma.

What is the mechanism of Levothyroxine?

It is a synthetic T4 replacement that increases metabolic rate and oxygen consumption.

What are the symptoms of excessive Levothyroxine dosage?

Nervousness, insomnia, diarrhea, weight loss, heat intolerance, tachycardia, dysrhythmias, angina, myocardial infarction, and heart failure.

When should Levothyroxine be taken?

In the morning on an empty stomach.

What should be avoided when taking Levothyroxine?

Antacids, iron supplements, and sucralfate, as they decrease absorption.

What is Propranolol used for in the context of hyperthyroidism?

Symptom control, as it does not treat the thyroid problem itself.

What is the role of Propranolol during thyroid treatment?

It serves as 'bridge therapy' while waiting for thionamides or radioactive iodine to take effect.