Week 11 - Chapter 58 Drugs for Thyroid Disorders

Question 1

Thyroid Hormones

Answer 1

--Profound effect on:
   >Metabolism:  Stimulate energy use
   >Cardiac function
   >Growth 
     --Promotes maturation in infancy and childhood
--Produces two active hormones whose synthesis is stimulated by low plasma levels of iodine
  >Triiodothyronine (T3)
    -Synthetic T3: Liothyronine
  >Thyroxine (T4, tetraiodothyronine)
    -Synthetic T4: Levothyroxine

Question 2

Hypothyroidism

Answer 2

-Deficiency of thyroid hormone
>Hypothyroidism/Myxedema (adults), Cretinism (infancy)
—Bradycardia, Lethargy, Fatigue, Cold Intolerance Impaired mental functon
—To help ensure healthy fetal development, maternal hypothyroidism must be diagnosed and treated very early

Question 3

Hypothyroidism

Causes…

Answer 3

> Usually due impaired thyroid
Hashimoto’s disease: Chronic autoimmune thyroiditis
Insufficient iodine in the diet
Surgical removal of thyroid and destruction of thyroid with radioactive iodine

Question 4

Hypothyroidism

Therapeutic therapy…

Answer 4

Lifelong replacement therapy:
_Levothyroxine (T4)
_Adverse Effects: Tachycardia, Angina, Tremors
_Liothyronine (T3)

Question 5

Hyperthyroidism

Two forms…

Answer 5

Graves’ disease
Most common form, women age 20 to 40 years
Causes exophthalmos
Autoimmune, Thyroid-stimulating immunoglobulins (TSH receptor agonist activity)
Toxic nodular goiter (thyroid adenoma)

Question 6

Hyperthyroidism

Treatment

Answer 6

• Surgical removal of thyroid tissue
• Destruction of thyroid tissue
• Suppression of thyroid hormone synthesis
• Beta blockers (for example, propranolol)
• Nonradioactive iodine

Question 7

Chronic autoimmune thyroiditis

Answer 7

Hashimoto’s disease (one of the causes of Hypothyroidism)

Question 8

Thyrotoxic Crisis (Thyroid Storm)

Signs

Answer 8

> Hyperthermia (105º F or higher), severe tachycardia, restlessness, agitation, tremor, unconsciousness, coma, hypotension, heart failure

Question 9

Thyrotoxic Crisis (Thyroid Storm)

Cause

Answer 9

> Patients with thyrotoxicosis who undergo significant stress (for example, surgery, illness)
Not triggered by a rise in thyroid hormones
Cannot be identified by laboratory testing

Question 10

Thyrotoxic Crisis (Thyroid Storm)

Treatment

Answer 10

> Methimazole
Beta blocker
Sedation, cooling, glucocorticoids, IV fluids