a nurse is preparing to administer phenytoin ...

a nurse is preparing to administer phenytoin 5 mg/kg/day po divided equally every 12 hr for an infant who weighs 12 lb 4 oz. how many mg should the nurse administer per dose? (round the answer to the nearest tenth. use a leading zero if it applies. do not use a trailing zero.)

Answer

# Explanation: ## Step1: Convert weight to kg 1 lb = 0.453592 kg, 1 oz = 0.0283495 kg. 12 lb 4 oz = 12×0.453592+4×0.0283495 = 5.443104 + 0.113398 = 5.556502 kg. ## Step2: Calculate daily dose The daily dose is 5 mg/kg, so for a 5.556502 - kg infant, the daily dose is 5×5.556502 = 27.78251 mg. ## Step3: Calculate per - dose amount The daily dose is divided every 12 hours (2 doses per day). So per - dose amount is $\frac{27.78251}{2}=13.891255$ mg. ## Step4: Round the answer Rounding 13.891255 mg to the nearest tenth gives 13.9 mg. # Answer: 13.9