What the label lists and what reports show
Infliximab side effects
Infliximab's FDA label: “Most common adverse reactions (>10%) – infections (e.g. upper respiratory, sinusitis, and pharyngitis), infusion-related reactions, headache, and abdominal pain.” FAERS holds 243,740 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 arthralgia (21,885 reports).
- No generic listed
- Boxed warning
Check it at the source: the infliximab FDA label on DailyMed (effective August 28, 2026); 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 RENFLEXIS?RENFLEXIS can cause serious side effects, including: See " What is the most important information I should know about RENFLEXIS? ". Serious Infections Some patients, especially those 65 years and older have had serious infections while receiving infliximab products, such as RENFLEXIS. These serious infections include TB and infections caused by viruses, fungi, or bacteria that have spread throughout the body or cause infections in certain areas (such as skin). Some patients die from these infections. If you get an infection while receiving treatment with RENFLEXIS your doctor will treat your infection and may need to stop your RENFLEXIS treatment. […]
Source: FDA drug label, Organon LLC, effective August 28, 2026 (SPL set dbf738c4-3fac-4422-a9d8-51d9c83a8789), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions (>10%) – infections (e.g. upper respiratory, sinusitis, and pharyngitis), infusion-related reactions, headache, and abdominal pain.
Table 2 Adverse Reactions that Occurred in ≥ 5% of Patients who Received ≥ 4 Infliximab Infusions for RA
| Average weeks of follow-up | Placebo (n = 350) 59 weeks | Infliximab (n = 1129) 66 weeks |
|---|---|---|
| Upper respiratory tract infection | 25% | 32% |
| Nausea | 20% | 21% |
| Headache | 14% | 18% |
| Sinusitis | 8% | 14% |
| Diarrhea | 12% | 12% |
| Abdominal pain | 8% | 12% |
| Pharyngitis | 8% | 12% |
| Coughing | 8% | 12% |
| Bronchitis | 9% | 10% |
| Rash | 5% | 10% |
| Dyspepsia | 7% | 10% |
| Fatigue | 7% | 9% |
| Urinary tract infection | 6% | 8% |
| Pain | 7% | 8% |
| Arthralgia | 7% | 8% |
| Pruritus | 2% | 7% |
| Fever | 4% | 7% |
| Hypertension | 5% | 7% |
| Moniliasis | 3% | 5% |
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, continuedMost common adverse reactions (>10%) – infections (e.g. upper respiratory, sinusitis, and pharyngitis), infusion-related reactions, headache, and abdominal pain. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Organon LLC, a subsidiary of Organon & Co., at 1-844-674-3200 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Adverse Reactions in Adults The data described herein reflect exposure to infliximab in 4779 adult patients (1304 patients with RA, 1106 patients with CD, 202 with AS, 293 with PsA, 484 with UC, 1373 with Ps, and 17 patients with other conditions), including 2625 patients exposed beyond 30 weeks and 374 exposed beyond 1 year. [For information on adverse reactions in pediatric patients see Adverse Reactions (6.1) ]. One of the most-common reasons for discontinuation of treatment was infusion-related reactions (e.g., dyspnea, flushing, headache and rash). Infusion-Related Reactions Adverse Reactions During or Shortly After Infusion An infusion reaction was defined in clinical trials as any adverse event occurring during an infusion or within 1 hour after an infusion. …
Source: FDA drug label, Organon LLC, effective August 28, 2026 (SPL set dbf738c4-3fac-4422-a9d8-51d9c83a8789), via openFDA; the full label on DailyMed
What do FAERS reports show?
243,740 reports list infliximab among the medicines taken, each a report of something that happened, not proof the medicine caused it; 14,395 are coded as a death and 70,690 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, 9 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?
- Infliximab: 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