A nurse is preparing to administer levothyroxine 100 mcg PO to a client who has hypothyroidism.

Available is levothyroxine 50 mcg tablets.

How many tablets should the nurse administer?
(Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)

Choice A rationale:
While distribution can affect a person’s response to medication, it is not the aspect of genetic makeup most likely to alter this response.
Choice B rationale:
Absorption can affect how a drug is taken up by the body, but it is not the aspect of genetic makeup most likely to alter a person’s response to medication.
Choice C rationale:
Excretion, or how the body eliminates a drug, can affect drug response, but it is not the aspect of genetic makeup most likely to alter this response.
Choice D rationale:
Metabolism, or how the body processes a drug, is the aspect of genetic makeup most likely to alter a person’s response to medication. Genetic differences can lead to variations in drug-metabolizing enzymes, affecting how quickly or slowly drugs are metabolized.

Choice A rationale:
Giving the medication as ordered despite the patient’s stated allergy could lead to a severe allergic reaction.
Choice B rationale:
While checking the drug insert for information on reactions to the drug is important, the immediate action should be to withhold the medication.
Choice C rationale:
Withholding the medication and notifying the prescriber of the situation is the safest course of action when a patient states they are allergic to the medication.
Choice D rationale:
Giving the medication and monitoring the patient for adverse effects is not safe if the patient has stated they are allergic to the medication.