Amantadine 150 mg PO every 12 hours. Available is Amantadine 50 mg/5 mL syrup. How many mL should the nurse administer per dose?

Amantadine 150 mg PO every 12 hours. Available is Amantadine 50 mg/5 mL syrup. How many mL should the nurse administer per dose?

• A. 5 mL
• B. 10 mL
• C. 15 mL
• D. 20 mL

Answer: (C)

Start with the concentration: the syrup is 50 mg in 5 mL, which is 10 mg per mL. The prescribed dose is 150 mg, so divide 150 mg by 10 mg/mL to get 15 mL. Another way to see it is that 150 mg is three times 50 mg, so you’d administer 5 mL × 3 = 15 mL per dose. Therefore, 15 mL should be given per dose.

Start with the concentration: the syrup is 50 mg in 5 mL, which is 10 mg per mL. The prescribed dose is 150 mg, so divide 150 mg by 10 mg/mL to get 15 mL. Another way to see it is that 150 mg is three times 50 mg, so you’d administer 5 mL × 3 = 15 mL per dose. Therefore, 15 mL should be given per dose.