If a prescription requires 500 mg of amoxicillin and tablets on hand are 250 mg, how many tablets should be administered?

• A. 5 tablets
• B. 2 tablets
• C. 1 tablet
• D. 6 tablets

Answer: (B)

To meet the prescribed dose, use the tablet strength you have. The prescription calls for 500 mg, and each tablet is 250 mg. You determine how many tablets by dividing the total dose by the per-tablet amount: 500 mg ÷ 250 mg per tablet = two tablets. So give two tablets to reach the correct dose. Giving more or fewer would overshoot or undershoot the intended amount (for example, five would be 1250 mg, one would be 250 mg, six would be 1500 mg).