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Drug side effects

palonosetron Side Effects

The reactions most often reported to the FDA for palonosetron (also sold as Aloxi), with demographics, serious outcomes, and reporting trends.

Data updated 2026-05-15

3,330
FAERS reports

Data from the FDA Adverse Event Reporting System (FAERS), 2004 to 2025. A FAERS report records a temporal association, not proof of cause. See our methodology for how figures are compiled and de-duplicated.

The most commonly reported side effects of palonosetron come from 3,330 reports to the FDA, broken down here by frequency, patient demographics, and serious outcomes.

This page analyzes 3,330 reports to the FDA Adverse Event Reporting System (FAERS) for palonosetron (Aloxi): the reactions reported most often, who reported them, serious outcomes such as hospitalization, and year-over-year trends. A FAERS report does not prove the drug caused the effect, and report volume tracks how widely a drug is used, not how likely an effect is for any one person. Educational information, not medical advice.

Total Reports

3,330

Reports Mentioning Death

519

15.6% of reports — not proof the medicine caused the death

Hospitalizations

1,660

49.8% of reports

Top Indication

Product Used For Unknown Indication

Most Reported Adverse Reactions

NAUSEA
399
FATIGUE
249
FEBRILE NEUTROPENIA
249
DIARRHOEA
246
VOMITING
246
NEUTROPENIA
245
ALOPECIA
223
DYSPNOEA
194
ANAEMIA
189
DEATH
174
DECREASED APPETITE
166
PYREXIA
164
ASTHENIA
151
THROMBOCYTOPENIA
142
CONSTIPATION
135
INFUSION RELATED REACTION
115
NEUROPATHY PERIPHERAL
114
PNEUMONIA
108
ABDOMINAL PAIN
104

Who Reports Side Effects

Gender Distribution

Female 1,806 (59%)
Male 1,271 (41%)
Unknown 6

Age Distribution

0-17 69 (2%)
18-44 288 (10%)
45-64 1,245 (45%)
65-74 803 (29%)
75+ 358 (13%)

Reporting Trend by Year

2004 2025

Reactions in Death Reports

Top reactions reported in 519 reports where death was an outcome. These are voluntarily reported and do not establish causation.

Reaction Reports
DEATH 174
FATIGUE 48
NAUSEA 43
DIARRHOEA 42
DISEASE PROGRESSION 40
PNEUMONIA 40
FEBRILE NEUTROPENIA 35
ANAEMIA 34
ASTHENIA 31
SEPSIS 30
PYREXIA 29
VOMITING 29
DECREASED APPETITE 28
NEUTROPENIA 27
DYSPNOEA 26
MALIGNANT NEOPLASM PROGRESSION 24
RESPIRATORY FAILURE 23
THROMBOCYTOPENIA 23
CONSTIPATION 22

Reactions in Hospitalization Reports

Top reactions in 1,660 reports where hospitalization was an outcome.

Reaction Reports
FEBRILE NEUTROPENIA 221
NAUSEA 173
NEUTROPENIA 155
VOMITING 134
ANAEMIA 122
DIARRHOEA 122
PYREXIA 115
DYSPNOEA 98
DECREASED APPETITE 91
PNEUMONIA 91
ASTHENIA 87
THROMBOCYTOPENIA 85
FATIGUE 77
DEHYDRATION 74
ACUTE KIDNEY INJURY 70
CONSTIPATION 70
HYPOTENSION 64
ABDOMINAL PAIN 62
HYPOKALAEMIA 55

Compare palonosetron vs alosetron →

What the FAERS Data Reveals About palonosetron Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 3,330 voluntary reports linked to palonosetron and its brand equivalents (Aloxi), spanning 2004 through 2025. Of those, 519 (15.6%) listed death as an outcome and 1,660 (49.8%) involved hospitalization. The most common indication reported alongside adverse events was Product Used For Unknown Indication.

Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 59% were female and 41% male; age distribution skews toward 45-64, with 1,245 reports in that bracket. The single most reported reaction is nausea with 399 submissions, followed by fatigue and febrile neutropenia.

How to read these numbers

FAERS is a signal-detection tool, not a scorecard. Reports are voluntary, and a single case may list multiple suspect drugs, so numbers above should not be read as incidence rates or per-patient risk. Widely prescribed drugs naturally accumulate more reports than niche therapies even when individual risk is low. These aggregates are useful for spotting patterns that merit further pharmacovigilance, not for choosing between medications. This page is for educational reference only and is not medical advice, speak with a licensed clinician about any side-effect concerns.