Question

a nurse is preparing to administer phenytoin suspension 300 mg po, twice per day. the amount available is phenytoin suspension 125 mg/5 ml. how many ml should the nurse administer per dose? (round the answer to the nearest whole number. use a leading zero if it applies. do not use a trailing zero.)

Explanation:

Step1: Set up the proportion

We know that the available suspension is 125 mg per 5 mL, and we need to find out how many mL (let's call this \( x \)) correspond to 300 mg. So we set up the proportion: \(\frac{125\space mg}{5\space mL}=\frac{300\space mg}{x\space mL}\)

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

Cross - multiplying gives us \( 125x = 300\times5 \). First, calculate the right - hand side: \( 300\times5=1500 \). Then, solve for \( x \) by dividing both sides of the equation by 125: \( x=\frac{1500}{125} \)

Step3: Simplify the fraction

\(\frac{1500}{125}=\frac{1500\div125}{125\div125}=12\)

Answer:

12