A nurse is preparing to administer phenobarbital 3 mg/kg/day PO in two divided doses to a client who weighs 145 lbs. The amount available is phenobarbital 100 mg/tablet. How many tablets should the nurse administer per dose?

To determine how many tablets of phenobarbital a nurse should administer per dose to a client weighing 145 lbs, first convert the weight to kilograms, calculate the total daily dosage, divide it by two, and relate it to the tablet strength. The calculation shows that 1 tablet is needed per dose.

Explanation:

The question involves calculating the correct dosage of phenobarbital to administer to a client, based on their weight, and then determining how many tablets to provide per dose given the medication's concentration in milligram per tablet format. To find the answer, first, convert the client's weight from pounds to kilograms (since 1 kg = 2.20462 lbs). Next, calculate the total daily dosage needed in milligrams, and finally, determine the number of tablets to administer per dose by dividing the total daily dosage by two (as it's to be given in two divided doses) and then dividing by the dosage concentration of the tablets available.

Step-by-Step Solution:

Convert weight: 145 lbs ÷ 2.20462 = approx. 65.77 kg.
Calculate total daily dosage in mg: 65.77 kg × 3 mg/kg = 197.31 mg.
Divide by two for the divided doses: 197.31 mg ÷ 2 = approx. 98.655 mg per dose.
Since tablets are 100 mg each, 1 tablet is needed per dose to meet the prescribed dosage closest.