Chapter 31: Thyroid and Anti-Thyroid Test, Pharmacology for Nurses: Practical Applications
The key terms in this Pharmacology course include Thyroid and Anti-Thyroid Test, Levothyroxine, Warfarin, intravenous (IV), Synthroid, hypothyroidism, estrogens, Pharmacology for Nurses: Practical Applications
For a patient taking levothyroxine and warfarin concurrently, the nurse would closely monitor for which possible serious adverse effect?
Acute confusion
Increased bruising
Orthostatic hypotension
Cardiac dysrhythmias
Levothyroxine can compete with protein-binding sites of warfarin, allowing more warfarin to be unbound or free, thus increasing effects of warfarin and risk of bleeding. Bleeding commonly presents as bruising.
The nurse has a prescription to change the patient’s levothyroxine dosage from oral to intravenous (IV). The patient takes 150 mcg/day by mouth, and the prescription is to administer 50% of the oral dose by the IV route. How much will the nurse administer per day? __
Correct Answer
75 mcg
150 mcg/day × 0.50 = 75 mcg
Levothyroxine (Synthroid) has been prescribed for a patient with hypothyroidism. The nurse reviews the patient’s current medications for potential interactions. Which of these drugs or drug classes interact with levothyroxine? (Select all that apply.)
Estrogens
Warfarin (Coumadin)
Iron supplements
Penicillins
Beta blockers
Phenytoin (Dilantin)
Drug interactions with thyroid preparations include phenytoin, cholestyramine, antacids, calcium salts, iron products, estrogens, and warfarin (see Table 31-3). The other options are not correct.
When reviewing the laboratory values of a patient who is taking antithyroid drugs, the nurse will monitor for which adverse effect?
Increased platelet count
Decreased glucose levels
Increased red blood cell count
Decreased white blood cell count
Antithyroid drugs may cause bone marrow suppression, resulting in agranulocytosis, leukopenia, thrombocytopenia, and other problems. The other options are incorrect.
A patient has a diagnosis of primary hypothyroidism. Which statement accurately describes this problem?
The hypothalamus is not secreting thyrotropin-releasing hormone (TRH); therefore, thyroid-stimulating hormone (TSH) is not released from the pituitary gland.
The pituitary gland is dysfunctional and is not secreting TSH.
The abnormality is caused by an insufficient intake of iodine.
The abnormality is in the thyroid gland itself.
Primary hypothyroidism stems from an abnormality in the thyroid gland itself and occurs when the thyroid gland is not able to perform one of its many functions. Secondary hypothyroidism begins at the level of the pituitary gland and results from reduced secretion of TSH. TSH is needed to trigger the release of the T3 and T4 stored in the thyroid gland. Tertiary hypothyroidism is caused by a reduced level of the TRH from the hypothalamus. This reduced level, in turn, reduces TSH and thyroid hormone levels.
When reviewing the laboratory values of a patient who is taking anti-thyroid drugs, the nurse will monitor for which adverse effect?
Increased platelet count
Decreased glucose levels
Increased red blood cell count
Decreased white blood cell count
Anti-thyroid drugs may cause bone marrow suppression, resulting in agranulocytosis, leukopenia, thrombocytopenia, and other problems. The other options are incorrect.