Neumega Side Effects Center

Last updated on RxList: 5/9/2022
Neumega Side Effects Center

What Is Neumega?

Neumega (oprelvekin) is a protein that stimulates production of platelets in the blood used to prevent platelets from becoming dangerously low in certain people receiving chemotherapy that can result in bone marrow suppression or the need for blood platelet transfusions.

What Are Side Effects of Neumega?

Common side effects of Neumega include:

  • injection site reactions (pain redness, or irritation),
  • red eyes,
  • dizziness,
  • headache,
  • sleep problems (insomnia),
  • nausea,
  • vomiting,
  • diarrhea,
  • runny or stuffy nose,
  • cough, or
  • sore throat

Dosage for Neumega

The recommended dose of Neumega in adults without severe renal impairment is 50 ยตg/kg given once daily, administered subcutaneously (under the skin) as a single injection.

What Drugs, Substances, or Supplements Interact with Neumega?

Other drugs may interact with Neumega. Tell your doctor all prescription and over-the-counter medications and supplements you use.

Neumega During Pregnancy or Breastfeeding

During pregnancy, Neumega should be used only when prescribed. It is unknown if this drug passes into breast milk but is unlikely to harm a nursing infant. Consult your doctor before breastfeeding.

Additional Information

Our Neumega (oprelvekin) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. The adverse reaction information from clinical trials does, however, provide a basis for identifying the adverse events that appear to be related to drug use and for approximating rates.

Three hundred twenty-four subjects, with ages ranging from eight months to 75 years, have been exposed to Neumega treatment in clinical studies. Subjects have received up to six (eight in pediatric patients) sequential courses of Neumega treatment, with each course lasting from one to 28 days. Apart from the sequelae of the underlying malignancy or cytotoxic chemotherapy, most adverse events were mild or moderate in severity and reversible after discontinuation of Neumega dosing.

In general, the incidence and type of adverse events were similar between Neumega 50 mcg/kg and placebo groups. The most frequently reported serious adverse events were neutropenic fever, syncope, atrial fibrillation, fever and pneumonia. The most commonly reported adverse events were edema, dyspnea, tachycardia, conjunctival injection, palpitations, atrial arrhythmias, and pleural effusions. The most frequently reported adverse reactions resulting in clinical intervention (eg, discontinuation of Neumega, adjustment in dosage, or the need for concomitant medication to treat an adverse reaction symptom) were atrial arrhythmias, syncope, dyspnea, congestive heart failure, and pulmonary edema (see WARNINGS, Fluid Retention and WARNINGS, Cardiovascular Events). Selected adverse events that occurred in ≥ 10% of Neumega-treated patients are listed in Table 3.


Body System
Adverse Event
n=67 (%)
50 mcg/kg
n=69 (%)
Body Bas Whole
  Edema 10 (15) 41 (59)
  Neutropenic fever 28 (42) 33 (48)
  Headache 24 (36) 28 (41)
  Fever 19 (28) 25 (36)
Cardiovascular System
  Tachycardia* 2 (3) 14 (20)
  Vasodilatation 6 (9) 13 (19)
  Palpitations* 2 (3) 10 (14)
  Syncope 4 (6) 9 (13)
  Atrial fibrillation/flutter* 1 (1) 8 (12)
Digestive System
  Nausea/vomiting 47 (70) 53 (77)
  Mucositis 25 (37) 30 (43)
  Diarrhea 22 (33) 30 (43)
  Oral moniliasis* 1 (1) 10 (14)
Nervous System
  Dizziness 19 (28) 26 (38)
  Insomnia 18 (27) 23 (33)
Respiratory System
  Dyspnea* 15 (22) 33 (48)
  Rhinitis 21 (31) 29 (42)
  Cough increased 15 (22) 20 (29)
  Pharyngitis 11 (16) 17 (25)
  Pleural effusions* 0 (0) 7 (10)
Skin and Appendages
  Rash 11 (16) 17 (25)
Special Senses
  Conjunctival Injection* 2 (3) 13 (19)
*Occurred in significantly more Neumega-treated patients than in placebo-treated patients.

The following adverse events also occurred more frequently in cancer patients receiving Neumega than in those receiving placebo: blurred vision, paresthesia, dehydration, skin discoloration, exfoliative dermatitis, and eye hemorrhage. Other than a higher incidence of severe asthenia in Neumega treated patients (10 [14%] in Neumega patients versus two [3%] in placebo patients), the incidence of severe or lifethreatening adverse events was comparable in the Neumega and placebo treatment groups.

Two patients with cancer treated with Neumega experienced sudden death that the investigator considered possibly or probably related to Neumega. Both deaths occurred in patients with severe hypokalemia ( < 3.0 mEq/L) who had received high doses of ifosfamide and were receiving daily doses of a diuretic (see WARNINGS, Cardiovascular Events).

Other serious events associated with Neumega were papilledema and cardiovascular events including atrial arrhythmias and stroke. In addition, cardiomegaly was reported in children.

The following adverse events, occurring in ≥ 10% of patients, were observed at equal or greater frequency in placebo-treated patients: asthenia, pain, chills, abdominal pain, infection, anorexia, constipation, dyspepsia, ecchymosis, myalgia, bone pain, nervousness, and alopecia. The incidence of fever, neutropenic fever, flu-like symptoms, thrombocytosis, thrombotic events, the average number of units of red blood cells transfused per patient, and the duration of neutropenia < 500 cells/μL were similar in the Neumega 50 mcg/kg and placebo groups.


In clinical studies that evaluated the immunogenicity of Neumega, two of 181 patients (1%) developed antibodies to Neumega. In one of these two patients, neutralizing antibodies to Neumega were detected in an unvalidated assay. The clinical relevance of the presence of these antibodies is unknown. In the post-marketing setting, cases of allergic reactions, including anaphylaxis have been reported (see WARNINGS, Allergic Reactions Including Anaphylaxis). The presence of antibodies to Neumega was not assessed in these patients.

The data reflect the percentage of patients whose test results were considered positive for antibodies to Neumega and are highly dependent on the sensitivity and specificity of the assay. Additionally the observed incidence of antibody positivity in an assay may be influenced by several factors including sample handling, concomitant medications, and underlying disease. For these reasons, comparisons of the incidence of antibodies to Neumega with incidence of antibodies to other products may be misleading.

Abnormal Laboratory Values

The most common laboratory abnormality reported in patients in clinical trials was a decrease in hemoglobin concentration predominantly as a result of expansion of the plasma volume (see WARNINGS, Fluid Retention). The increase in plasma volume is also associated with a decrease in the serum concentration of albumin and several other proteins (eg, transferrin and gamma globulins). A parallel decrease in calcium without clinical effects has been documented.

After daily SC injections, treatment with Neumega resulted in a two-fold increase in plasma fibrinogen. Other acute-phase proteins also increased. These protein levels returned to normal after dosing with Neumega was discontinued. Von Willebrand factor (vWF) concentrations increased with a normal multimer pattern in healthy subjects receiving Neumega.

Post-marketing Reports

Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Decisions to include these reactions in labeling are typically based on one or more of the following factors: (1) seriousness of the reactions, (2) frequency of reporting, or (3) strength of causal connection to Neumega.

The following adverse reactions have been reported during the post-marketing use of Neumega:

Read the entire FDA prescribing information for Neumega (Oprelvekin)

© Neumega Patient Information is supplied by Cerner Multum, Inc. and Neumega Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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