To calculate the amount of nafcillin that should be given to Tony, we need to determine the volume of the solution needed to provide 150 mg of nafcillin.

QUESTION

Tony is to receive nafcillin 150 mg IM. There is a 1 gram vial of nafcillin in Tony’s drug drawer. The directions on the vial state that when reconstituted with 3.4 ml sterile water for injection, each vial contains 4 ml solution of sodium nafcillin equivalent to 250 mg nafcillin per ml, buffered with 10 mg sodium citrate. How many mls of nafcillin should you give Tony?

ANSWER

To calculate the amount of nafcillin that should be given to Tony, we need to determine the volume of the solution needed to provide 150 mg of nafcillin.

The vial of nafcillin contains 1 gram (1000 mg) when reconstituted with 3.4 ml of sterile water for injection, resulting in a total volume of 4 ml solution. This solution is equivalent to 250 mg of nafcillin per 1 ml.

To calculate the volume needed to provide 150 mg of nafcillin, we can use the following proportion:

\( \text{Dose needed (mg)} : \text{Dose available (mg/ml)} = \text{Volume needed (ml)} : \text{Total volume (ml)} \)

Substituting the values:

\( 150 : 250 = x : 4 \)

Solving for \( x \):

\( x = \frac{150 \times 4}{250} = 2.4 \)

Therefore, Tony should receive 2.4 ml of nafcillin solution to provide 150 mg of nafcillin.

In this case, administering 2.4 ml of the nafcillin solution would ensure that Tony receives the prescribed dose of 150 mg of nafcillin. It’s essential to follow precise medication calculations to ensure accurate and safe administration of medications.