Thyroid and Antithyroid Drugs

Question 1

Thyroid Replacement Drugs

Answer 1

MOA:
Work in same manner as endogenous thyroid hormones

Indications:
Replace thyroid hormones the thyroid gland can’t produce

Contraindications:
Drug allergy, recent MI, adrenal insufficiency, & hyperthyroidism

Adverse Effects:
Usually result from overdose. Table 31-2

Interactions:
Oral anticoagulants, digitalis, hypoglycemic drugs

Nursing Considerations:

• educate pt on cardiac AEs
• look at med list for drug interactions

Question 2

Levothyroxine

Answer 2

• most common synthetic hormone/drug of choice
• pure thyroxine (T4)
• long half-life
• give on empty stomach, in morning, only once a day
• don’t switch between brands!
• can take up to 4 weeks for S/S to subside

Question 3

Antithyroid Drugs

Answer 3

only MOA:
Impede (slows down) formation of thyroid hormone

Indications:
Hyperthyroidism or after surgery/radioactive iodine therapy

Contraindications:
Drug allergy and maybe pregnant too

Adverse Effects:
Table 31-4, most serious are liver and bone marrow toxicity

Interactions:
Bone marrow depressants (have additive leukopenic effect) & oral anticoagulants (increase activity)

Nursing Considerations:

• monitor liver labs and WBC
• make take 2 weeks for effects to show
• avoid eating foods high in iodine

Question 4

Propylthiouracil (PTU)

Answer 4

only available in PO form

• monitor liver labs and WBC
• make take 2 weeks for effects to show
• avoid eating foods high in iodine