The nurse is to administer 6,000 units of heparin subcutaneously. The vial reads 10,000 units per mL. How many milliliters should be administered?

• A. 0.6 mL
• B. 0.5 mL
• C. 1.0 mL
• D. 0.4 mL

Answer: (A)

When you have a dose to give in units and a stock concentration in units per mL, you convert to milliliters by dividing the desired units by the concentration. Here, 6,000 units divided by 10,000 units per mL equals 0.6 mL. So you should administer 0.6 mL.

Why this fits: 0.6 mL × 10,000 U/mL = 6,000 U, matching the prescribed amount.

If you used 0.5 mL, you’d deliver 5,000 U; if you used 1.0 mL, you’d deliver 10,000 U; and if you used 0.4 mL, you’d deliver 4,000 U. None of those meet the 6,000-unit dose.