Drug · FAERS side-effect profile with label screen
Palonosetron side effects: what 3,494 FDA adverse event reports show
Drug class
Serotonin-3 (5-ht 3 ) receptor antagonist
FDA label, Indications wording
Brand names
Posfrea
openFDA label
Who reports
3,494 reports · 92% serious · 550 with death outcome · 58% female
openFDA FAERS counts, all years, deduplication not applied
Used for
POSFREA is indicated in adults for prevention of: acute and delayed nausea and vomiting associated with initial and repeat courses of moderately emetogenic cancer chemotherapy (MEC). acute nausea and vomiting associated with initial and repeat courses highly emetogenic cancer chemotherapy (HEC). postoperative nausea and vomiting (PONV) for up to 24 hours following surgery.
FDA label, Indications and Usage
What it is
POSFREA Injection contains palonosetron as palonosetron HCl, an antiemetic and antinauseant agent. It is a serotonin-3 (5-HT 3 ) receptor antagonist with a strong binding affinity for this receptor.
FDA label, Description section
Boxed warning
None in the current label
How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation.
Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)?
That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.
Causality screen of the 40 strongest signals
Labeled adverse reaction 2Labeled (related wording) 1Reporting / coding artifact 1Lab value / disease marker 2Not in label — unassessed 34
What the badges mean
- Labeled adverse reaction The exact term appears in the label's warnings or adverse-reactions sections: a known, expected effect. The FAERS signal confirms the label rather than discovering anything.
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
Strongest disproportionality signals
Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only and flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 116 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Hair colour changes | 58 | 27.8 21.5–35.9ROR 28.2 · χ² 1,465 / p <1e-300 | 27.4 EB05 22.0 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=8 · ♀ 100% (drug 58%) | no trial data cached |
| Hair texture abnormal | 58 | 25.9 20.0–33.4ROR 26.3 · χ² 1,358 / p 1e-297 | 25.6 EB05 20.5 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=8 · ♀ 100% (drug 58%) | no trial data cached |
| Madarosis | 49 | 25.2 19.1–33.3ROR 25.5 · χ² 1,111 / p 8e-244 | 24.9 EB05 19.6 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=6 · ♀ 100% (drug 58%) | no trial data cached |
| Febrile neutropenia | 256 | 23.3 20.7–26.2ROR 25.0 · χ² 5,431 / p <1e-300 | 23.2 EB05 20.9 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious PRR 14.5 · 95% clinician | no trial data cached |
| Inappropriate antidiuretic hormone secretion | 27 | 15.9 10.9–23.2ROR 16.1 · χ² 363 / p 4e-81 | 15.6 EB05 11.0 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 10.1 · ♀ 13% (drug 58%) · 100% clinician | no trial data cached |
| Hypomagnesaemia | 36 | 15.6 11.3–21.6ROR 15.8 · χ² 477 / p 6e-106 | 15.3 EB05 11.4 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 10.0 | no trial data cached |
| Cytokine release syndrome | 48 | 15.1 11.4–20.1ROR 15.3 · χ² 619 / p 6e-137 | 14.9 EB05 11.6 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 9.6 · ♀ 18% (drug 58%) · 100% clinician | no trial data cached |
| Polyneuropathy | 28 | 14.1 9.8–20.5ROR 14.3 · χ² 329 / p 1e-73 | 13.7 EB05 9.7 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 8.9 · 100% clinician | no trial data cached |
| Neutrophil count decreased | 88 | 13.1 10.6–16.0ROR 13.4 · χ² 967 / p 1e-212 | 12.9 EB05 10.8 · IC025 +3.3 3/3 methods agree | Lab value / disease marker | serious PRR 9.1 · 95% clinician | no trial data cached |
| Respiratory depression | 24 | 11.8 7.9–17.5ROR 11.8 · χ² 225 / p 3e-51 | 11.0 EB05 7.4 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 7.6 · 96% clinician | no trial data cached |
| Hypokalaemia (low potassium) | 87 | 11.4 9.3–14.0ROR 11.7 · χ² 814 / p 2e-179 | 11.2 EB05 9.3 · IC025 +3.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.2 | no trial data cached |
| Neutropenia (low neutrophils (infection-fighting cells)) | 253 | 11.2 10.0–12.6ROR 12.0 · χ² 2,356 / p <1e-300 | 11.1 EB05 10.0 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 7.2 · 93% clinician | no trial data cached |
| Infusion related reaction (reaction during infusion) | 120 | 10.9 9.2–13.0ROR 11.3 · χ² 1,072 / p 2e-235 | 10.8 EB05 9.2 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 7.0 · 98% clinician | no trial data cached |
| Mucosal inflammation | 45 | 10.4 7.8–13.9ROR 10.5 · χ² 372 / p 4e-83 | 9.9 EB05 7.6 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 6.7 · 95% clinician | no trial data cached |
| Oral candidiasis (oral thrush) | 22 | 10.2 6.7–15.4ROR 10.2 · χ² 172 / p 1e-39 | 9.2 EB05 6.1 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 8.9 · 100% clinician | no trial data cached |
| Leukopenia (low white blood cells) | 82 | 9.9 8.0–12.2ROR 10.1 · χ² 645 / p 1e-142 | 9.6 EB05 7.9 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.3 · 94% clinician | no trial data cached |
| Myelosuppression | 55 | 9.7 7.5–12.6ROR 9.8 · χ² 421 / p 7e-94 | 9.3 EB05 7.3 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 6.0 · 98% clinician | no trial data cached |
| Pneumonitis | 43 | 9.6 7.1–12.9ROR 9.7 · χ² 321 / p 5e-72 | 9.1 EB05 6.9 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 · 95% clinician | no trial data cached |
| Thrombotic microangiopathy | 15 | 9.3 5.6–15.4ROR 9.3 · χ² 103 / p 2e-24 | 7.9 EB05 4.8 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 5.8 | no trial data cached |
| Bacteraemia | 18 | 9.2 5.8–14.6ROR 9.2 · χ² 123 / p 7e-29 | 8.0 EB05 5.2 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 5.8 | no trial data cached |
| Thrombocytopenia (low platelets) | 148 | 8.0 6.8–9.3ROR 8.3 · χ² 899 / p 9e-198 | 7.8 EB05 6.8 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 5.1 · 95% clinician | no trial data cached |
| Sinus tachycardia | 18 | 7.6 4.8–12.1ROR 7.7 · χ² 97 / p 3e-23 | 6.6 EB05 4.3 · IC025 +1.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.9 | no trial data cached |
| Hyperbilirubinaemia | 13 | 7.6 4.4–13.0ROR 7.6 · χ² 68 / p 9e-17 | 6.2 EB05 3.8 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 4.8 | no trial data cached |
| Neuropathy peripheral (nerve damage in hands/feet) | 119 | 7.6 6.3–9.0ROR 7.8 · χ² 673 / p 1e-148 | 7.4 EB05 6.3 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 5.3 · 93% clinician | no trial data cached |
| Lymphocyte count decreased | 22 | 7.5 4.9–11.3ROR 7.5 · χ² 117 / p 2e-27 | 6.6 EB05 4.5 · IC025 +2.0 3/3 methods agree | Lab value / disease marker | serious PRR 5.5 · 100% clinician | no trial data cached |
| Ileus | 15 | 7.3 4.4–12.1ROR 7.3 · χ² 76 / p 2e-18 | 6.2 EB05 3.9 · IC025 +1.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.6 | no trial data cached |
| Stomatitis (mouth sores) | 73 | 7.2 5.8–9.1ROR 7.4 · χ² 386 / p 3e-86 | 7.0 EB05 5.7 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 6.7 | no trial data cached |
| Impaired quality of life | 17 | 7.1 4.4–11.4ROR 7.1 · χ² 83 / p 4e-20 | 6.1 EB05 4.0 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 | no trial data cached |
| Palmar-plantar erythrodysaesthesia syndrome | 27 | 6.9 4.8–10.1ROR 7.0 · χ² 131 / p 1e-30 | 6.3 EB05 4.5 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 5.8 · ♀ 88% (drug 58%) | no trial data cached |
| Alopecia (hair loss) | 225 | 6.9 6.0–7.8ROR 7.3 · χ² 1,131 / p 3e-248 | 6.8 EB05 6.1 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 6.7 · ♀ 94% (drug 58%) | no trial data cached |
| Upper gastrointestinal haemorrhage | 19 | 6.8 4.3–10.6ROR 6.8 · χ² 88 / p 4e-21 | 5.9 EB05 4.0 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 4.2 | no trial data cached |
| Hypoxia (low oxygen) | 38 | 6.5 4.7–8.9ROR 6.6 · χ² 172 / p 2e-39 | 6.1 EB05 4.6 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 4.0 · 94% clinician | no trial data cached |
| Ventricular fibrillation | 12 | 6.5 3.7–11.4ROR 6.5 · χ² 50 / p 7e-13 | 5.3 EB05 3.2 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.1 | no trial data cached |
| Anaemia (low red blood cells) | 199 | 6.3 5.5–7.2ROR 6.6 · χ² 881 / p 6e-194 | 6.2 EB05 5.5 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.3 · 95% clinician | no trial data cached |
| Small intestinal obstruction | 12 | 5.9 3.3–10.3ROR 5.9 · χ² 44 / p 2e-11 | 4.9 EB05 3.0 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 | no trial data cached |
| Altered state of consciousness | 21 | 5.8 3.8–9.0ROR 5.9 · χ² 80 / p 2e-19 | 5.2 EB05 3.6 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 · 95% clinician | no trial data cached |
| Pancytopenia (all blood cells low) | 51 | 5.5 4.2–7.2ROR 5.6 · χ² 183 / p 5e-42 | 5.2 EB05 4.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 3.5 · 90% clinician | no trial data cached |
| Device related infection | 14 | 5.4 3.2–9.2ROR 5.5 · χ² 46 / p 5e-12 | 4.7 EB05 3.0 · IC025 +1.3 3/3 methods agree | Reporting / coding artifact | serious PRR 3.5 | no trial data cached |
| Brain fog | 13 | 5.3 3.1–9.2ROR 5.4 · χ² 42 / p 5e-11 | 4.6 EB05 2.8 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 6.4 | no trial data cached |
| Leukocytosis | 16 | 5.3 3.3–8.7ROR 5.3 · χ² 52 / p 3e-13 | 4.7 EB05 3.0 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 3.4 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Nausea | 432 | 3.3 3.0–3.6ROR 3.6 · χ² 711 / p 6e-157 | 3.3 EB05 3.0 · IC025 +1.6 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 3.6 | no trial data cached |
| Vomiting | 259 | 3.3 2.9–3.7ROR 3.5 · χ² 426 / p 7e-95 | 3.3 EB05 3.0 · IC025 +1.5 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 3.0 | no trial data cached |
| Febrile neutropenia | 256 | 23.3 20.7–26.2ROR 25.0 · χ² 5,431 / p <1e-300 | 23.2 EB05 20.9 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious PRR 14.5 · 95% clinician | no trial data cached |
| Neutropenia (low neutrophils (infection-fighting cells)) | 253 | 11.2 10.0–12.6ROR 12.0 · χ² 2,356 / p <1e-300 | 11.1 EB05 10.0 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 7.2 · 93% clinician | no trial data cached |
| Alopecia (hair loss) | 225 | 6.9 6.0–7.8ROR 7.3 · χ² 1,131 / p 3e-248 | 6.8 EB05 6.1 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 6.7 · ♀ 94% (drug 58%) | no trial data cached |
| Anaemia (low red blood cells) | 199 | 6.3 5.5–7.2ROR 6.6 · χ² 881 / p 6e-194 | 6.2 EB05 5.5 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.3 · 95% clinician | no trial data cached |
| Decreased appetite (loss of appetite) | 178 | 4.6 4.0–5.3ROR 4.8 · χ² 505 / p 3e-112 | 4.6 EB05 4.0 · IC025 +1.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.2 · 91% clinician | no trial data cached |
| Thrombocytopenia (low platelets) | 148 | 8.0 6.8–9.3ROR 8.3 · χ² 899 / p 9e-198 | 7.8 EB05 6.8 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 5.1 · 95% clinician | no trial data cached |
| Constipation | 144 | 4.0 3.4–4.7ROR 4.1 · χ² 323 / p 1e-72 | 3.9 EB05 3.4 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.3 · 93% clinician | no trial data cached |
| Infusion related reaction (reaction during infusion) | 120 | 10.9 9.2–13.0ROR 11.3 · χ² 1,072 / p 2e-235 | 10.8 EB05 9.2 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 7.0 · 98% clinician | no trial data cached |
| Neuropathy peripheral (nerve damage in hands/feet) | 119 | 7.6 6.3–9.0ROR 7.8 · χ² 673 / p 1e-148 | 7.4 EB05 6.3 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 5.3 · 93% clinician | no trial data cached |
| Neutrophil count decreased | 88 | 13.1 10.6–16.0ROR 13.4 · χ² 967 / p 1e-212 | 12.9 EB05 10.8 · IC025 +3.3 3/3 methods agree | Lab value / disease marker | serious PRR 9.1 · 95% clinician | no trial data cached |
| Hypokalaemia (low potassium) | 87 | 11.4 9.3–14.0ROR 11.7 · χ² 814 / p 2e-179 | 11.2 EB05 9.3 · IC025 +3.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.2 | no trial data cached |
| Dehydration | 86 | 3.9 3.1–4.8ROR 3.9 · χ² 181 / p 1e-41 | 3.8 EB05 3.2 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 2.8 | no trial data cached |
| Platelet count decreased | 86 | 4.8 3.9–6.0ROR 4.9 · χ² 260 / p 1e-58 | 4.7 EB05 3.9 · IC025 +1.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.5 · 94% clinician | no trial data cached |
Unlabeled candidate signals
These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.
- Hair colour changes — n=58, PRR 27.8
- Hair texture abnormal — n=58, PRR 25.9
- Madarosis — n=49, PRR 25.2
- Febrile neutropenia — n=256, PRR 23.3
- Inappropriate antidiuretic hormone secretion — n=27, PRR 15.9
- Hypomagnesaemia — n=36, PRR 15.6
- Cytokine release syndrome — n=48, PRR 15.1
- Polyneuropathy — n=28, PRR 14.1
- Respiratory depression — n=24, PRR 11.8
- Neutropenia — n=253, PRR 11.2
Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.
Common questions
What are the most reported side effects of Palonosetron?
In FDA FAERS, the most frequently co-reported reaction terms for Palonosetron are nausea, vomiting, febrile neutropenia, neutropenia, alopecia, anaemia. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.
Does Palonosetron have an FDA boxed warning?
No. The FDA label retrieved for Palonosetron has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Palonosetron causes these side effects?
No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.
Sources & methods
- FDA label via openFDA (set ID 13a201ba-c86d-48c5-a0e1-a3e0b4e6a2a7, effective 20250429; matched on
openfda.generic_name.exact:"PALONOSETRON") - Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 156 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath
Page generated 2026-10-08. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.