A nurse is preparing to administer amoxicillin 400 mg PO every 12 hr. The amount available is amoxicillin 250 mg/5 ml suspension. How many mL should the number in a single dose? (Round the answer to the nearest whole number) __mL

To calculate the correct volume of amoxicillin suspension to administer, use the standard dosage calculation formula: (Desired dose ÷ Available dose per unit volume) × Volume per unit. The desired dose is 400 mg, and the available concentration is 250 mg per 5 mL. First, divide the desired dose by the available dose: 400 mg ÷ 250 mg = 1.6. Then multiply by the volume per unit: 1.6 × 5 mL = 8 mL. Rounded to the nearest whole number, the answer is 8 mL per dose. A common error is inverting the ratio — placing 250 in the numerator and 400 in the denominator — which would yield an incorrect smaller volume. Another frequent mistake is failing to account for the per-5-mL concentration and treating the problem as if the concentration were per 1 mL. Students should always confirm the units match before performing the calculation and use dimensional analysis to cross-check their work. Administering an incorrect volume can lead to subtherapeutic dosing or toxicity, so precision in dosage calculations is essential. In clinical practice, the nurse would also verify the order, check the client's allergy history, and confirm the suspension has been properly reconstituted and stored before administration.