What the label lists and what reports show
Isoflurane side effects
Isoflurane's FDA label: “Most common adverse reactions (incidence ≥ 5%) are agitation, cough, breath holding, nausea, chills/shivering, vomiting, laryngospasm, delirium.” FAERS holds 1,935 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 hypotension (236 reports).
- Generic listed
Check it at the source: the isoflurane FDA label on DailyMed (effective January 5, 2026, Shandong New Time Pharmaceutical Co., Ltd.); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsMost common adverse reactions (incidence ≥ 5%) are agitation, cough, breath holding, nausea, chills/shivering, vomiting, laryngospasm, delirium.
A table the label prints in its adverse reactions section without a title; its column headings name the groups compared
| Adverse Reaction | Frequency |
|---|---|
| Delirium | 6.2% |
| Induction | 28.2% |
| Induction | 8.0% |
| Recovery | 9.5% |
| Chills/shivering | 14.0% |
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, continuedADVERSE REACTIONS Most common adverse reactions (incidence ≥ 5%) are agitation, cough, breath holding, nausea, chills/shivering, vomiting, laryngospasm, delirium. (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Emprise Pharma LLC. at (610) 933-1969 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience The following adverse reactions were identified from controlled clinical trials of adult and pediatric subjects exposed to isoflurane, USP liquid for inhalation. The trials were conducted using a variety of pre-medications, other anesthetics, and surgical procedures of varying lengths. The most serious reported adverse reactions in alphabetical order are agitation, arrhythmia, breath holding, elevated liver enzyme, hypotension and laryngospasm. The most frequent adverse reactions (incidence ≥ 5%) described in Table 1 are agitation, breath holding, chills/shivering, cough, delirium, laryngospasm, nausea, and vomiting. Adverse reactions with an incidence between 1% and 5% are provided in Table 2. Adverse reactions with an incidence less than 1% are provided in Table 3. 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, Shandong New Time Pharmaceutical Co., Ltd., effective January 5, 2026 (SPL set 662ceaf6-650b-4dea-bbee-652f46426024), via openFDA; the full label on DailyMed
What do FAERS reports show?
1,935 reports list isoflurane among the medicines taken, each a report of something that happened, not proof the medicine caused it; 299 are coded as a death and 742 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 20 reactions below, 6 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?
- Isoflurane: 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