Oprelvekin

Definition

Oprelvekin, also known as Neumega, is a hematopoietic stimulant used as supportive care after myelosuppressive chemotherapy to combat thrombopenia.

Purpose

Oprelvekin is a prescription medication used following the administration of myelosuppressive chemotherapy drugs such as azathioprine and mercaptopurine . Myelosuppressive chemotherapy acts on bone marrow and causes a decrease in the amount of white blood cells (leukopenia) and platelets (thrombopenia). Oprelvekin acts as a growth factor stimulating stem cells to proliferate. The result is an increase in the amount of platelets (or thrombocytes).

Description

Oprelvekin is a recombinant human interleukin. Further it is a synthetic version of the naturally occurring interleukin-11, which is produced by the cells of the bone marrow. It is a growth factor that stimulates the formation of platelets, which are necessary in the process of blood clot formation. Oprelvekin is therefore important in increasing platelet formation after treatment with cancer medications that cause thrombocytopenia .

The Food and Drug Administration approve oprelvekin for prevention of severe thrombocytopenia, which is observed after chemotherapy. In 2000 oprelvekin was in clinical trials for treatment support and therapy for acute myelocytic leukemia .

Recommended dosage

This drug is available by injection. The dose is different from person to person and is dependent on the patient's body weight. Generally, 50 mcg/kg is given once daily in either the abdomen, thigh or hip. This medication should be taken at the same time every day for best results. If a dosage of oprelvekin is missed, the patient should skip the missed dose and take the next dose at the scheduled time.

Precautions

Although oprelvekin is effective at increasing the number of platelets in patients following chemotherapy, patients should understand that there are a number of precautions that should be taken when their physician is prescribing oprelvekin.

If the patient has any existing medical problems, he or she should tell the doctor prior to beginning treatment with oprelvekin. Congestive heart failure may be worsened when taking oprelvekin as it causes increased water retention. Oprelvekin can also cause atrial arrhythmias that result in heart rhythm problems. It should also be used with caution in patients with preexisting papilledema or with tumors that involve the central nervous system.

Oprelvekin has not been studied in pregnant women, women who are nursing or children. However, animal testing has shown that oprelvekin can have negative effects on the fetus and can cause joint and tendon problems in children. It is eliminated primarily by the kidneys and should be used carefully in patients with renal impairment.

Side effects

Although oprelvekin is a synthetic version of a naturally occurring growth factor, there are side effects associated with taking it. The side effects should be weighed against the needed effects of this medication. Some side effects do not require medical attention and others do.

The following are side effects that do not require medical attention and could gradually go away as treatment progresses:

• red eyes
• weakness
• numb extremities such as the hands and feet
• skin reactions such as rash and discoloration

If patients encounter any of the following side effects, they should contact their physicians immediately:

• rapid heartbeat
• irregular heartbeat
• short breath
• white spots in the mouth or on the tongue
• swelling feet and legs
• bloody eye
• blurred vision
• heart rhythm problems

If the patient notices any other side effects not listed, they should contact their physician immediately.

Interactions

There are no known drug interactions with oprelvekin.

Sally C. McFarlane-Parrott

KEY TERMS

Growth factor

—A body-produced substance that regulates cell division and cell survival. It can also be produced in a laboratory for use in biological therapy.

Hematopoietic

—Related to the formation of blood cells.

Thrombopenia

—Decreased number of platelets.

Papilledema

—Swelling around the optic disk.