To determine the required volume in milliliters (mL) to administer 120 mg of furosemide using a stock concentration of 40 mg/2 mL, follow these steps:
Step 1: Identify Given ValuesStep 2: Set Up a ProportionUse the formula:
Volume required (mL)=(Ordered dose (mg)Stock concentration (mg/mL))\text{Volume required (mL)} = \left( \frac{\text{Ordered dose (mg)}}{\text{Stock concentration (mg/mL)}} \right)Volume required (mL)=(Stock concentration (mg/mL)Ordered dose (mg)​)
First, determine the concentration inmg per mL:
40 mg2 mL=20 mg/mL\frac{40 \text{ mg}}{2 \text{ mL}} = 20 \text{ mg/mL}2 mL40 mg​=20 mg/mL
Now, calculate the required volume:
120 mg20 mg/mL=6 mL\frac{120 \text{ mg}}{20 \text{ mg/mL}} = 6 \text{ mL}20 mg/mL120 mg​=6 mL
Thus, the correct answer is6 mL.
Final Answer: C. 6 mLPharmacy Technician References:
PTCB PTCE Exam Content Outline (Medication Order Interpretation & Dosage Calculations)
USP <797> Guidelines for Sterile Compounding
Mosby’s Pharmacy Technician Exam Review
American Pharmacists Association (APhA) Pharmacy Technician Guide
