What the label lists and what reports show
Eculizumab side effects
Eculizumab's FDA label: “The most frequently reported adverse reactions in the PNH randomized trial (≥10% overall and greater than placebo) are: headache, nasopharyngitis, back pain, and nausea.” FAERS holds 54,046 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 fatigue (5,890 reports).
- No generic listed
- Boxed warning
Check it at the source: the eculizumab FDA label on DailyMed (effective July 8, 2026, Alexion Pharmaceuticals 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 SOLIRIS?SOLIRIS can cause serious side effects including: See " What is the most important information I should know about SOLIRIS? " Serious infusion-related reactions. Serious infusion-related reactions can happen during your SOLIRIS infusion. Tell your healthcare provider or nurse right away if you get any of these symptoms during your SOLIRIS infusion: chest pain trouble breathing or shortness of breath swelling of your face, tongue, or throat feel faint or pass out If you have an infusion-related reaction to SOLIRIS, your healthcare provider may need to infuse SOLIRIS more slowly or stop SOLIRIS. […]
Source: FDA drug label, Alexion Pharmaceuticals Inc., effective July 8, 2026 (SPL set ebcd67fa-b4d1-4a22-b33d-ee8bf6b9c722), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most frequently reported adverse reactions in the PNH randomized trial (≥10% overall and greater than placebo) are: headache, nasopharyngitis, back pain, and nausea.
Table 6: Per Patient Incidence of Adverse Events in 10% or More Adult and Adolescent Patients Enrolled in Studies C08-002A/B, C08-003A/B and C10-004 Separately and in Total
| Reaction | C08-002A/B (N=17) | C08-003A/B (N=20) | C10-004 (N=41) | Total (N=78) |
|---|---|---|---|---|
| Hypertension includes the preferred terms hypertension, accelerated hypertension, and… | 10 (59) | 9 (45) | 7 (17) | 26 (33) |
| Hypotension | 2 (12) | 4 (20) | 7 (17) | 13 (17) |
| Bronchitis | 3 (18) | 2 (10) | 4 (10) | 9 (12) |
| Nasopharyngitis | 3 (18) | 11 (55) | 7 (17) | 21 (27) |
| Gastroenteritis | 3 (18) | 4 (20) | 2 (5) | 9 (12) |
| Upper respiratory tract infection | 5 (29) | 8 (40) | 2 (5) | 15 (19) |
| Urinary tract infection | 6 (35) | 3 (15) | 8 (20) | 17 (22) |
| Diarrhea | 8 (47) | 8 (40) | 12 (32) | 29 (37) |
| Vomiting | 8 (47) | 9 (45) | 6 (15) | 23 (30) |
| Nausea | 5 (29) | 8 (40) | 5 (12) | 18 (23) |
| Abdominal pain | 3 (18) | 6 (30) | 6 (15) | 15 (19) |
| Headache | 7 (41) | 10 (50) | 15 (37) | 32 (41) |
| Anemia | 6 (35) | 7 (35) | 7 (17) | 20 (26) |
| Leukopenia | 4 (24) | 3 (15) | 5 (12) | 12 (15) |
| Insomnia | 4 (24) | 2 (10) | 5 (12) | 11 (14) |
| Renal Impairment | 5 (29) | 3 (15) | 6 (15) | 14 (18) |
| Proteinuria | 2 (12) | 1 (5) | 5 (12) | 8 (10) |
| Cough | 4 (24) | 6 (30) | 8 (20) | 18 (23) |
| Fatigue | 3 (18) | 4 (20) | 3 (7) | 10 (13) |
| Peripheral edema | 5 (29) | 4 (20) | 9 (22) | 18 (23) |
| Pyrexia | 4 (24) | 5 (25) | 7 (17) | 16 (21) |
| Asthenia | 3 (18) | 4 (20) | 6 (15) | 13 (17) |
| Eye Disorder | 5 (29) | 2 (10) | 8 (20) | 15 (19) |
| Hypokalemia | 3 (18) | 2 (10) | 4 (10) | 9 (12) |
| Neoplasms benign, malignant, and unspecified (including cysts and polyps) | 1 (6) | 6 (30) | 1 (20) | 8 (10) |
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: Serious Meningococcal Infections [see Warnings and Precautions (5.1) ] Other Infections [see Warnings and Precautions (5.3) ] Monitoring Disease Manifestations after SOLIRIS Discontinuation [see Warnings and Precautions (5.4) ] Thrombosis Prevention and Management [see Warnings and Precautions (5.5) ] Infusion-Related Reactions [see Warnings and Precautions (5.6) ] The most frequently reported adverse reactions in the PNH randomized trial (≥10% overall and greater than placebo) are: headache, nasopharyngitis, back pain, and nausea. ( 6.1 ) The most frequently reported adverse reactions in aHUS single arm prospective trials (≥20%) are: headache, diarrhea, hypertension, upper respiratory infection, abdominal pain, vomiting, nasopharyngitis, anemia, cough, peripheral edema, nausea, urinary tract infections, pyrexia. ( 6.1 ) The most frequently reported adverse reaction in the gMG placebo-controlled clinical trial (≥10%) in adult patients is musculoskeletal pain. ( 6.1 ) The most frequently reported adverse reactions in the NMOSD placebo- controlled trial (≥10%) are: upper respiratory infection, nasopharyngitis, diarrhea, back pain, dizziness, influenza, arthralgia, pharyngitis, and contusion.
Source: FDA drug label, Alexion Pharmaceuticals Inc., effective July 8, 2026 (SPL set ebcd67fa-b4d1-4a22-b33d-ee8bf6b9c722), via openFDA; the full label on DailyMed
What do FAERS reports show?
54,046 reports list eculizumab among the medicines taken, each a report of something that happened, not proof the medicine caused it; 5,614 are coded as a death and 15,307 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?
- Eculizumab: 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