A physician orders amoxicillin 50 mg/mL for a child at 1 mL PO q8h for 10 days. What is the total volume to be dispensed, in mL, if the amoxicillin stock is 125 mg/5 mL?
A. 2
B. 30
C. 60
D. 150
A physician orders amoxicillin 50 mg/mL for a child at 1 mL PO q8h for 10 days. What is the total volume to be dispensed, in mL, if the amoxicillin stock is 125 mg/5 mL?
Share
C. 60
First, find how many mg the child should receive per day according to the instructions. Taking 1 mL of 50 mg/mL amoxicillin q8h means that the child will be taking 50 mg every 8 hours, or three times a day:
50 mg per dose x 3 doses per day = 150 mg per day
Since the stock amoxicillin contains 125 mg per 5 mL, this means that the stock contains 25 mg per mL. Divide 150 mg per day by 25 mg/mL to find how many mL are required per day:
150 mg per day ÷ 25 mg/mL = 6 mL per day
Finally, multiply the total mL required per day by the total days of therapy to find how many mL are needed to complete the course:
6 mL per day x 10 days of therapy = 60 mL total
C. 60