What the label lists and what reports show
Filgrastim side effects
Filgrastim's FDA label: “Most common adverse reactions in patients: With nonmyeloid malignancies receiving myelosuppressive anti-cancer drugs (≥ 5% difference in incidence compared to placebo) are pyrexia, pain, rash, cough, and dyspnea.” FAERS holds 41,194 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is pyrexia (3,007 reports).
- No generic listed
Check it at the source: the filgrastim FDA label on DailyMed (effective July 23, 2026, Amgen, Inc); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of NEUPOGEN?NEUPOGEN can cause serious side effects, including: Spleen rupture. Your spleen may become enlarged and can rupture. A ruptured spleen can cause death. Tell your healthcare provider right away if you develop pain in the left upper stomach (abdomen) area or your left shoulder. A serious lung problem called acute respiratory distress syndrome (ARDS). Tell your healthcare provider or get emergency medical help right away if you develop shortness of breath with or without a fever, trouble breathing, or a fast rate of breathing. Serious allergic reactions. Allergic reactions can cause a rash over your whole body, shortness of breath, wheezing, dizziness, swelling around your mouth or eyes, fast heart rate, and sweating. If you develop any of these symptoms, stop using NEUPOGEN and tell your healthcare provider or get emergency medical help right away. […]
Source: FDA drug label, Amgen, Inc, effective July 23, 2026 (SPL set 97cc73cc-b5b7-458a-a933-77b00523e193), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions in patients: With nonmyeloid malignancies receiving myelosuppressive anti-cancer drugs (≥ 5% difference in incidence compared to placebo) are pyrexia, pain, rash, cough, and dyspnea.
Table 2. Adverse Reactions in Patients with Cancer Receiving Myelosuppressive Chemotherapy (With ≥ 5% Higher Incidence in NEUPOGEN Compared to Placebo)
| Body System Adverse Reactions | NEUPOGEN (N = 294) | Placebo (N = 157) |
|---|---|---|
| Thrombocytopenia | 38% | 29% |
| Nausea | 43% | 32% |
| Pyrexia | 48% | 29% |
| Chest pain | 13% | 6% |
| Pain | 12% | 6% |
| Fatigue | 20% | 10% |
| Back pain | 15% | 8% |
| Arthralgia | 9% | 2% |
| Bone pain | 11% | 6% |
| Pain in extremity Percent difference (NEUPOGEN – Placebo) was 4%. | 7% | 3% |
| Dizziness | 14% | 3% |
| Cough | 14% | 8% |
| Dyspnea | 13% | 8% |
| Rash | 14% | 5% |
| Blood lactate dehydrogenase increased | 6% | 1% |
| Blood alkaline phosphatase increased | 6% | 1% |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following serious adverse reactions are discussed in greater detail in other sections of the labeling: Splenic Rupture [see Warnings and Precautions (5.1) ] Acute Respiratory Distress Syndrome [see Warnings and Precautions (5.2) ] Serious Allergic Reactions [see Warnings and Precautions (5.3) ] Sickle Cell Disorders [see Warnings and Precautions (5.4) ] Glomerulonephritis [see Warnings and Precautions (5.5) ] Alveolar Hemorrhage and Hemoptysis [see Warnings and Precautions (5.6) ] Capillary Leak Syndrome [see Warnings and Precautions (5.7) ] Myelodysplastic Syndrome [see Warnings and Precautions (5.8) ] Acute Myeloid Leukemia [see Warnings and Precautions (5.8) ] Thrombocytopenia [see Warnings and Precautions (5.9) ] Leukocytosis [see Warnings and Precautions (5.10) ] Cutaneous Vasculitis [see Warnings and Precautions (5.11) ] Large and Medium Vessel Arteritis [see Warnings and Precautions (5.15) ] Most common adverse reactions in patients: With nonmyeloid malignancies receiving myelosuppressive anti-cancer drugs (≥ 5% difference in incidence compared to placebo) are pyrexia, pain, rash, cough, and dyspnea. ( 6.1 ) With AML (≥ 2% difference in incidence) are pain, epistaxis and rash. ( 6.1 ) With nonmyeloid malignancies undergoing myeloablative chemotherapy followed by BMT (≥ 5% difference in incidence) is rash. …
Source: FDA drug label, Amgen, Inc, effective July 23, 2026 (SPL set 97cc73cc-b5b7-458a-a933-77b00523e193), via openFDA; the full label on DailyMed
What do FAERS reports show?
41,194 reports list filgrastim among the medicines taken, each a report of something that happened, not proof the medicine caused it; 9,304 are coded as a death and 17,754 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 18 reactions below, 10 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Filgrastim: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions