A nurse is reinforcing teaching with a parent of an infant who has a prescription for amoxicillin 100 mg PO every 8 hr. Available is amoxicillin suspension 200 mg/5 mL. The nurse should tell the parent to administer how many tsp per dose? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)

Desired dose = 100 mg. Available concentration = 200 mg/5 mL. Find the concentration in mg per mL: Concentration (mg/mL) = 200 mg / 5 mL = 40 mg/mL. Calculate the volume to administer in milliliters (mL). Volume (mL) = Desired dose (mg) / Concentration (mg/mL) = 100 mg / 40 mg/mL = 2.5 mL. Convert the volume from milliliters (mL) to teaspoons (tsp). conversion factor: 1 tsp = 5 mL. Volume (tsp) = Volume (mL) / 5 mL/tsp = 2.5 mL / 5 mL/tsp = 0.5 tsp.