IP
Meaning of IP: Delivering a drug into the abdominal cavity bathes the surfaces directly, reaching concentrations that a vein could not produce at the same tissue.
Definition of IP
IP stands for intraperitoneal, meaning within the peritoneal cavity, the space around the abdominal organs enclosed by a thin lining called the peritoneum. As a route of administration it describes fluid or medication placed directly into that space rather than swallowed or injected into a vein. The abbreviation appears in treatment protocols, dialysis orders and laboratory research.
How does it compare with other routes?
The peritoneal cavity is a potential space, normally holding only a thin film of lubricating fluid. Instilling a large volume opens it up and puts the solution in contact with the outer surface of the bowel, liver and other organs. Absorption into the bloodstream then happens slowly across that lining, which is the point: local concentration stays high for far longer than a vein could sustain.
| Route | Where the drug goes first | Typical use |
|---|---|---|
| Intraperitoneal | Directly onto abdominal surfaces, absorbed slowly | Some abdominal chemotherapy, peritoneal dialysis |
| Intravenous | Straight into the circulation, distributed body-wide | Most systemic drug delivery |
| Oral | Gut, then the liver before the rest of the body | Everyday medication |
Where is the IP route used?
The two main clinical settings are dialysis and cancer treatment. In peritoneal dialysis, a sugar-rich solution is run into the cavity through a permanent catheter, left to dwell while waste products and excess water cross the peritoneum into it, then drained and replaced. In selected abdominal cancers, particularly ovarian cancer that has spread across the peritoneal surfaces, intraperitoneal chemotherapy delivers drug straight to deposits sitting on that lining. The tradeoff is that penetration into tissue is measured in millimeters, so the approach suits surface disease rather than bulky tumor.
What does the route demand in practice?
Access requires a catheter placed through the abdominal wall, and that opening is a route for organisms as well as for fluid, so peritonitis is the characteristic complication. Filling the cavity also raises pressure inside the abdomen, which can cause discomfort and press on the diaphragm. Compared with an intravenous infusion, the technique is more involved, the monitoring is different, and the pattern of side effects reflects the abdomen rather than the whole body. In animal research, IP injection is common because it is quick and reliable, and papers state the route explicitly for that reason.
Also known as
Used in a sentence
The treatment protocol specified IP administration of the chemotherapy agent.
Good to know
IP administration is distinguished from intravenous administration by its route and the pattern of absorption that results, which can influence both the local concentration achieved and the potential side effects observed.