Azithromycin 500 mg, daily for sepsis, is mixed in 250 mL of 0.9% saline. The drop factor is 15 gtts/mL and the infusion is to run over 60 minutes. What is the flow rate in drops per minute (rounded to the nearest whole number)?

Azithromycin 500 mg, daily for sepsis, is mixed in 250 mL of 0.9% saline. The drop factor is 15 gtts/mL and the infusion is to run over 60 minutes. What is the flow rate in drops per minute (rounded to the nearest whole number)?

• A. 63 gtt/min
• B. 50 gtt/min
• C. 75 gtt/min
• D. 90 gtt/min

Answer: (A)

Flow rate in IV infusions is found by converting the total volume and the time into milliliters per minute, then converting that to drops using the drop factor. The bag is 250 mL over 60 minutes, so 250 ÷ 60 ≈ 4.17 mL per minute. With a drop factor of 15 gtt/mL, the rate is 4.17 × 15 ≈ 62.5 drops per minute, which rounds to 63 gtt/min. The other rates would imply different volumes per hour (for example, 50 gtt/min → about 3.33 mL/min, delivering 200 mL in an hour; 75 gtt/min → 5 mL/min, delivering 300 mL in an hour), so they don’t match the given setup.

Flow rate in IV infusions is found by converting the total volume and the time into milliliters per minute, then converting that to drops using the drop factor. The bag is 250 mL over 60 minutes, so 250 ÷ 60 ≈ 4.17 mL per minute. With a drop factor of 15 gtt/mL, the rate is 4.17 × 15 ≈ 62.5 drops per minute, which rounds to 63 gtt/min. The other rates would imply different volumes per hour (for example, 50 gtt/min → about 3.33 mL/min, delivering 200 mL in an hour; 75 gtt/min → 5 mL/min, delivering 300 mL in an hour), so they don’t match the given setup.