The clinic nurse is providing medication teaching to a client with type 2 diabetes mellitus who is prescribed 35 mg glipizide daily in 2 divided doses. How many tablets per dose (tablets/dose) of glipizide should the nurse instruct the client to take? Record your answer using one decimal place.
Correct Answer: 3.5 tablets/dose
Using dimensional analysis, perform the following steps to calculate the administration quantity of glipizide in tablets per dose:
Identify the prescribed, available, and required medication information
Prescribed: 35 mg glipizide / day Available: 5 mg glipizide / tablet Required: tablets glipizide / dose
Convert the prescription to the quantity of glipizide in tablets per dose
Prescription × available medication = tablets glipizide / dose
OR
( mg glipizide / day ) ( day / doses ) ( tablet / mg glipizide ) = tablets glipizide / dose
OR
( 35 mg glipizide / day ) ( day / 2 doses ) ( tablet / 5 mg glipizide ) = 3.5 tablets glipizide / dose
Educational objective:
To calculate the administration quantity of glipizide, the nurse should first identify the prescribed dose (eg, 35 mg/day) and available medication (eg, 5 mg/tablet) and then convert to tablets per dose (eg, 3.5 tablets/dose).
The formula method is an alternate way to calculate medication dosages. However, this method may increase the occurrence of miscalculation and medication errors. If you choose to use this method, do not round any calculations until the final step.
Using the formula method, perform the following steps to calculate the administration quantity of glipizide in tablets per dose:
Calculate the prescription in milligrams per dose
( 35 mg glipizide / day ) ( day / 2 doses ) = 17.5 mg / dose
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Convert the prescription to the quantity of glipizide in tablets per dose
Prescribed dose / available dose x available volume = tablets glipizide / dose
OR
17.5 mg glipizide / 5 mg glipizide x tablet = 3.5 tablets glipizide / dose