Chapter 31- Thyroid and Antithyroid drugs

Question 1

Hyperthyroidism

Answer 1

A condition characterized by excessive production of the thyroid hormone. Also called thyrotoxicosis

Question 2

Hypothyroidism

Answer 2

A condition characterized by diminished production of the thyroid hormones.
Three types: Primary: abnormality in thyroid gland itself. Secondary: Pituitary gland is dysfunctional and does not secrete TSH. Tertiary: hypothalamus gland does not secrete TRH.

Question 3

Thyroid-stimulating hormone(TSH)

Answer 3

An endogenous substance (also called thyrotropin) secreted by the pituitary gland that controls the release of thyroid gland hormones and is necessary for the growth and function of the thyroid gland.

Question 4

Thyroxine (T4)

Answer 4

The principle thyroid hormone that influences the metabolic rate.

Question 5

Triiodothyronine (T3)

Answer 5

A secondary thyroid hormone that also affects body metabolism

Question 6

Thyroid Gland

Answer 6

Secretes three hormones essential for proper regulation of metabolism- t4, t3, and Calcitonin

Question 7

Hypothyroidism Cretinism

Answer 7

Hypo secretion of thyroid hormone during youth.

Low metabolic rate, retarded growth and sexual development, possible mental retardation

Question 8

Hypothyroidism Myxedema

Answer 8

Hypo secretion of thyroid hormone during adulthood.

Decreased metabolic rate, loss of mental and physical stamina, weight gain, loss of hair, yellow dullness of skin.

Question 9

Goitre

Answer 9

Enlargement of the thyroid gland resulting from overstimulation of elevated levels of TSH

Question 10

Hypothyroidism Symptoms

Answer 10

Thickened skin, hair loss, constipation, lethargy, anorexia

Question 11

Thyroid augmentation Drugs/ Mech of Action

Answer 11

levothyroxine (Eltroxin, Euthyrox, Synthroid)

Replace what the thyroid gland cannot produce. Thyroid drugs work the same as thyroid hormones.

Question 12

Thyroid augmentation indications

Answer 12

Treat all three forms of hypothyroidism.
Also used for thyroid glands that have been surgically removed or destroyed by radioactive iodine in thyroid cancer treatment

Question 13

Thyroid augmentation Contraindications

Answer 13

Recent MI
Adrenal insufficiency
Hyperthyroidism

Question 14

Thyroid Augmentation adverse effects

Answer 14

Cardiac dysrhythmia, tachycardia, palpitations, hypertension, tremors, headache, anxiety, nausea, heat intolerance

Question 15

Thyroid Augmentation Interactions

Answer 15

Dosages of many drugs may need to be adjusted
Many drugs will have an extended effect.
Increase the degradation of Vitamin K-dependent clotting factors.
Increase requirements for insulin and digoxin.
Increase cardiac responsiveness to epinephrine, dopamine, or dobutamine.
Phenytoin, carbamazepine, rifampin, sertraline, and phenobarbital increase metabolism.

Question 16

Hyperthyroidism

Answer 16

Caused by several diseases such as Graves’ disease.

Diarrhea, Flushing

Question 17

Treatment of Hyperthyroidism

Answer 17

Radioactive iodine

Antithyroid drugs- methimazole (Trapazole). propythiouracil

Question 18

Antithyroid drugs

Answer 18

May cause liver and bone marrow toxicity. Always check liver!

Question 19

Pharmacokinetics of Levothyroxine sodium (Eltroxin, Euthryox, Synthroid)

Answer 19

Half-life 9-10days.
Onset 2 days
More than 99% protein bound
Risk of toxicity

Question 20

Nursing Implications

Answer 20

Taken with food at the same time each day. Never stop abruptly.
Avoid eating foods high in iodine (Seafood, soy sauce, tofu, and iodized salts)!!!!!