Chapter 40 - Hyperthyroidism and Hypothyroidism

Question 1

Antithyroid drugs

• propylthiouracil (PTU)

Answer 1

 propylthiouracil (PTU)
 MOA: Inhibits the production of thyroid hormones and peripheral conversion of T4 to the more active T3
 Use: Hyperthyroidism, pre-op thyroidectomy, thyroid storm and before/after radioactive iodine therapy
 AE: Hypothyroidism, hematologic effects, dermatologic effects, CNS effects, GI effects, edema, drug fever, joint pain, lymphadenopathy
 BBW: Severe liver injury

Question 2

Thyroid drugs

• levothyroxine (Synthroid)

Answer 2

 levothyroxine (Synthroid)
 MOA: Increases the metabolic rate in the body’s tissues, increasing oxygen consumption, RR, and HR. Increases metabolism of fats, CHO, and proteins
 Use: Replacement therapy for hypothyroidism
 AE: Hyperthyroidism (and its symptoms)
 BBW: Do not use for weight loss!

Question 3

Beta Blockers

• propranolol (Inderal)

Answer 3

 propranolol (Inderal)
 MOA: Blocks beta-adrenergic receptors in various organs and thereby controls symptoms of hyperthyroidism resulting from excessive stimulation of sympathetic nervous system
• These symptoms include tachycardia, palpitations, excessive sweating, tremors, and nervousness
 Use: Treatment of cardiovascular conditions, such as dysrhythmias, angina pectoris, and hypertension ; also used for controlling symptoms during the delayed response to thioamide drugs and radioactive iodine, before thyroidectomy, and in treating thyrotoxic crisis
 Patient education: When patient becomes euthyroid and definitive treatment has controlled hyperthyroid symptoms, it is necessary to taper and discontinue use of drug