A nurse is preparing to administer cefadroxil oral suspension 15 mg/kg PO to a client who weighs 98 lb. Available is cefadroxil 250 mg/5 mL. Which of the following actions should the nurse take first?

Choice A reason: Calculating the dosage in milligrams is necessary, but it cannot be done until the client’s weight is converted to kilograms. Since the order is based on mg/kg, the first step must be to determine the weight in kilograms. Choice B reason: Converting the client’s weight to kilograms is the first and most essential step. The client weighs 98 lb. Step 1: 98 ÷ 2.2 = 44.5 kg. This conversion provides the basis for calculating the correct dose in mg/kg. Without this step, the dosage calculation would be inaccurate. Step-by-step dosage calculation (for clarity): Step 1: Convert weight to kilograms → 98 ÷ 2.2 = 44.5 kg. Step 2: Multiply by ordered dose → 44.5 × 15 mg = 667.5 mg. Step 3: Determine concentration → 250 mg ÷ 5 mL = 50 mg/mL. Step 4: Divide required dose by concentration → (667.5 ÷ 50) = 13.35 mL. Step 5: Round to nearest whole number → 13 mL. Thus, the nurse should administer 13 mL of cefadroxil suspension after completing all steps. Choice C reason: Rounding the amount to the nearest whole number is done at the final stage of calculation, after determining the exact dose in milliliters. It is not the first step and should only be performed once the precise dose is calculated. Choice D reason: Calculating the dosage in milliliters is also necessary, but it comes after determining the dose in milligrams. Since the available concentration is 250 mg/5 mL, the nurse must first know the required mg dose before converting it to mL.