Before starting a secondary (piggyback) IV antibiotic, the LVN should first:

Rationale: A. Disconnecting the primary IV tubing is incorrect because the primary line usually remains connected. Secondary (piggyback) medications are administered through the same IV access using a Y-site or secondary port, so disconnecting the primary line is unnecessary and may disrupt therapy. B. Verifying compatibility and ensuring the primary line is patent is correct. Before administering a secondary IV medication, the nurse must confirm that the antibiotic is compatible with the primary IV fluid to prevent precipitation, inactivation, or harmful reactions in the line. Ensuring the primary line is patent confirms that fluids can flow properly and reduces the risk of infiltration or line occlusion. This step is crucial for patient safety and effective medication delivery. C. Opening the roller clamp fully to start the antibiotic quickly is unsafe. IV medications must be administered at the correct rate as prescribed to avoid adverse reactions, including hypotension, phlebitis, or fluid overload. Rapid infusion can be harmful. D. Lowering the primary IV bag below the pump is unnecessary when administering a secondary IV infusion. Secondary medications are typically infused via a pump or gravity into the primary line, and correct setup of the secondary tubing ensures the primary fluid is appropriately paused or reduced during infusion.