What the label lists and what reports show
Remifentanil side effects
Remifentanil's FDA label: “Most common adverse reactions (incidence ≥ 1%) were respiratory depression, bradycardia, hypotension, and skeletal muscle rigidity.” FAERS holds 2,362 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 anaphylactic shock (357 reports).
- Generic listed
- In shortage
- Boxed warning
- DEA Schedule II
Check it at the source: the remifentanil FDA label on DailyMed (effective December 15, 2025, Mylan Institutional LLC); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsMost common adverse reactions (incidence ≥ 1%) were respiratory depression, bradycardia, hypotension, and skeletal muscle rigidity.
Table 16: Adverse Events Reported in ≥ 1% of Patients in the Post-Study Drug Phase of Cardiac Surgery Studies at the Recommended Doses See Table 4 for recommended doses. of ULTIVA
| Adverse Event | ULTIVA n = 227 | Fentanyl n = 176 | Sufentanil n = 41 |
|---|---|---|---|
| Nausea | 90 (40%) | 63 (36%) | 16 (39%) |
| Vomiting | 33 (15%) | 26 (15%) | 3 (7%) |
| Fever | 30 (13%) | 15 (9%) | 0 |
| Atrial fibrillation | 27 (12%) | 33 (19%) | 4 (10%) |
| Constipation | 20 (9%) | 35 (20%) | 3 (7%) |
| Pleural effusion | 11 (5%) | 2 (1%) | 2 (5%) |
| Hypotension | 8 (4%) | 8 (5%) | 1 (2%) |
| Tachycardia | 9 (4%) | 15 (9%) | 0 |
| Postoperative complication | 10 (4%) | 6 (3%) | 2 (5%) |
| Oliguria | 7 (3%) | 7 (4%) | 1 (2%) |
| Confusion | 7 (3%) | 10 (6%) | 5 (12%) |
| Ache | 6 (3%) | 2 (1%) | 0 |
| Anxiety | 6 (3%) | 6 (3%) | 0 |
| Headache | 6 (3%) | 2 (1%) | 0 |
| Perioperative complication | 5 (2%) | 7 (4%) | 1 (2%) |
| Anemia | 5 (2%) | 5 (3%) | 1 (2%) |
| Agitation | 5 (2%) | 3 (2%) | 1 (2%) |
| Diarrhea | 5 (2%) | 1 (< 1%) | 1 (2%) |
| Edema | 4 (2%) | 6 (3%) | 0 |
| Dizziness | 4 (2%) | 3 (2%) | 1 (2%) |
| Postoperative infection | 5 (2%) | 7 (4%) | 0 |
| Hypoxia | 4 (2%) | 5 (3%) | 0 |
| Apnea | 4 (2%) | 1 (< 1%) | 1 (2%) |
| Hypertension | 3 (1%) | 3 (2%) | 0 |
| Shivering | 3 (1%) | 1 (< 1%) | 0 |
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 described, or described in greater detail, in other sections: • Addiction, Abuse, and Misuse [see Warnings and Precautions (5.1) ] • Life-Threatening Respiratory Depression [see Warnings and Precautions (5.2) ] • Interactions with Benzodiazepines or other CNS Depressants [see Warnings and Precautions (5.3) ] • Opioid-Induced Hyperalgesia and Allodynia [see Warnings and Precautions (5.4) ] • Serotonin Syndrome [see Warnings and Precautions (5.5) ] • Skeletal Muscle Rigidity [see Warnings and Precautions (5.6) ] • Bradycardia [see Warnings and Precautions (5.8) ] • Hypotension [see Warnings and Precautions (5.9) ] • Biliary Tract Disease [see Warnings and Precautions (5.12) ] • Seizures [see Warnings and Precautions (5.13) ] Most common adverse reactions (incidence ≥ 1%) were respiratory depression, bradycardia, hypotension, and skeletal muscle rigidity. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Viatris at 1-877-446-3679 (1-877-4-INFO-RX) 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.
Source: FDA drug label, Mylan Institutional LLC, effective December 15, 2025 (SPL set 4dbcb8f9-1987-4b66-bd2f-d251fda0be10), via openFDA; the full label on DailyMed
What do FAERS reports show?
2,362 reports list remifentanil among the medicines taken, each a report of something that happened, not proof the medicine caused it; 244 are coded as a death and 891 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 22 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?
- Remifentanil: 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