An intravenous (IV) piggyback is a way to administer medication through an intravenous line that is inserted into a patient's vein. This can be an antibiotic or another type of medication that needs to be diluted and administered slowly. The medication in an IV piggyback is mixed in a small amount of compatible fluid, such as normal saline or dextrose with saline.

The IV piggyback is aptly named because it is given on top of the main intravenous solution. This allows for the intermittent infusion of medications at specific times. The piggyback infusion is usually hung higher than the main IV solution; it is then connected to a port in the main tubing above the IV pump. The nurse can program the IV pump as a secondary, which will stop the main IV infusion and allow the secondary medication to infuse. Once the IV piggyback is finished, the main fluids will begin to infuse once again.

A piggyback infusion can also be administered without a main IV fluid infusing. A patient can have IV access called a saline lock or heparin lock. A saline lock is an intravenous catheter that is inserted into a vein and then capped off. This allows periodic access to the vein for medication administration. An IV piggyback may be attached to the saline lock every few hours, and then disconnected once the medication has infused.

The medications in the piggyback infusion may not be compatible with other IV piggybacks. If two incompatible medications mix in the same line, it could form a precipitate or crystallize in the tubing. Therefore, it is important that the intravenous tubing be flushed in between IV piggyback administrations. This flush can be performed by lowering the secondary tubing to allow the main intravenous solution to back up into the secondary line to flush it.

Some hospital policies require a separate secondary IV piggyback line for each medication. When there is a dedicated line for each medicine, there is little risk for incompatible medications mixing together. This can become a challenge if a patient is on several intravenous piggybacks due to the amount of IV lines that will be hanging from the pole.

If the patient does not have a main intravenous fluid infusing, the saline lock should be flushed with normal saline before and after the administration of an intravenous piggyback. This will clear any remaining medication left behind in the saline lock.