What Is Pegfilgrastim?

Pegfilgrastim is a generic medication commonly marketed under the brand name Neulasta®. A doctor may prescribe it to cancer patients undergoing chemotherapy. While this is not a chemotherapy drug, it can be used to help reduce the risk of infection that chemotherapy can cause. It is a colony stimulating factor drug that encourages the growth of new white blood cells produced by the bone marrow. Sometimes, a doctor may also prescribe pegfilgrastim for patients who will undergo a stem cell transplant.

This medication is only available as a solution for injection, which may be administered by a health care professional or by a patient at home. Adults will typically be prescribed a pre-filled syringe that contains 6 milligrams (mg) of the medicine. It may not be administered every day, but rather the doctor will explain exactly when to use it. Pegfilgrastim is not intended for use within one day after a dose of chemotherapy or 14 days before it, because patients will be at a heightened risk of side effects.

The syringes must be stored in the refrigerator. Before using a dose, the patient should allow the syringe to sit at room temperature for 30 minutes. After sterilizing an area of skin, the injection is given subcutaneously, or under the skin. It should never be injected into broken, bruised, or irritated skin. Patients should choose a new injection site for each dose.

Some side effects may occur with the use of pegfilgrastim, which should be reported to the doctor if they are troublesome or severe. Patients may notice the injection sites developing lumps, bruises, or swelling. The area may also be reddish or tender to the touch. Bone pain may also develop, which can be relieved with an over-the-counter pain reliever such as acetaminophen. Patients should avoid taking aspirin.

Rarely, more serious side effects may occur, which require immediate medical help. Pegfilgrastim may rarely cause damage to the spleen, which is life-threatening. Signs of this complication can include severe stomach or abdominal pain. Other serious side effects can include shoulder pain, rapid breathing, or difficulty breathing. Patients should be mindful of symptoms of an infection, which can include a fever, sore throat, and chills.

Before taking pegfilgrastim to help prevent infections, patients must disclose their other medical conditions, medications, and supplements. As of 2011, it is unknown whether this drug may pass into breast milk. Women who are pregnant should avoid its use whenever possible. Pegfilgrastim should not be used during radiation therapy or by those who have certain allergies, such as latex allergies. This drug may interfere with the results of some laboratory tests.