Health Promotion and Maintenance
50. A physician orders penicillin 200,000 units/kg/day IV q6h for a child weighing 16 kg. The penicillin on hand comes prepared in a concentration of 250,000 units/mL. In order to administer the correct dose, a nurse calculates that _______ mL of penicillin should be administered to the child.
Test-Taking Tip
Approach pharmacology math questions in a stepwise fashion, paying attention to the number of doses given in a 24-hour day rather than the hours between doses (in this example, divide by 4 doses per day, not by 6 hours between doses).
Content Area: Child Health, Medication Administration; Integrated Process: Nursing Process, Implementation; Cognitive Level: Application; Client Need/Subneed: Physiological Integrity/Pharmacological and Parenteral Therapies/Dosage Calculation
Health Promotion and Maintenance
3.2
To solve this problem, first multiply the ordered 200,000 units per kilogram by the child's weight of 16 kg to get a total of 3,200,000 units per day. Next, divide the total daily units of 3,200,000 by 4 (since the drug is administered every 6 hours) to get a single dose of 800,000 units. Finally, take the single dose of 800,000 units and divide by the 250,000 units per mL to get a total of 3.2 mL.