Pyrogen test is performed to check the presence or absence of pyrogens in all aqueous parenterals. Rabbits are used to perform the test because their body temperature increases when pyrogen is introduced by the parenteral route.

What is the purpose of pyrogen?

The pyrogens inhibit heat-sensing neurons and excite cold-sensing ones, and the altering of these temperature sensors deceives the hypothalamus into thinking the body is cooler than it actually is. In response, the hypothalamus raises the body's temperature above the normal range, thereby causing a fever.

What does the pyrogen test measure?

The test methods measure cytokine levels (either IL-1-beta or IL-6) from human blood cells or a human monocytoid cell line. Increased cytokine release is used as a biomarker of a pyrogenic response.