Question

a nurse is preparing to administer cephalexin 250 mg po every 8 hr to a child. the amount available is cephalexin suspension 125 mg/5 ml. how many ml should the nurse administer per dose? (round the answer to the nearest tenth/whole number. use a leading zero if it applies. do not use a trailing zero.)

Explanation:

Step1: Set up the proportion

Let \( x \) be the volume in mL to administer. The concentration is \( 125 \, \text{mg/5 mL} \), and we need to find \( x \) for \( 250 \, \text{mg} \). So we set up the proportion: \(\frac{125 \, \text{mg}}{5 \, \text{mL}}=\frac{250 \, \text{mg}}{x \, \text{mL}}\)

Step2: Cross - multiply and solve for \( x \)

Cross - multiplying gives \( 125x = 250\times5 \). First, calculate the right - hand side: \( 250\times5 = 1250 \). Then, solve for \( x \) by dividing both sides by 125: \( x=\frac{1250}{125}\)

Step3: Calculate the value of \( x \)

\(\frac{1250}{125}=10\)

Answer:

10