Purixan side effects: what 777 FDA adverse event reports show
Drug class
Nucleoside metabolic inhibitor
Who reports
777 reports · 81% serious · 27 with death outcome · 48% female
Used for
PURIXAN is a nucleoside metabolic inhibitor indicated for the treatment of patients with acute lymphoblastic leukemia (ALL) as part of a combination chemotherapy maintenance regimen.( 1.1 ) 1.1 Acute Lymphoblastic Leukemia PURIXAN is indicated for the treatment of patients with acute lymphoblastic leukemia (ALL) as part of a combination chemotherapy maintenance regimen.
What it is
Mercaptopurine, a nucleoside metabolic inhibitor.
Boxed warning
None in the current label
Causality screen of the 14 strongest signals
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. 4 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Hepatotoxicity (liver damage) | 24 | 29.2 19.7–43.4ROR 30.1 · χ² 627 / p 1e-138 | 28.6 EB05 20.2 · IC025 +3.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 20.2 · 100% clinician | no trial data cached |
| Hepatocellular injury | 10 | 19.0 10.3–35.2ROR 19.2 · χ² 153 / p 2e-35 | 17.7 EB05 9.3 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 13.4 | no trial data cached |
| Bone marrow failure | 14 | 18.5 11.0–31.1ROR 18.8 · χ² 214 / p 8e-49 | 17.7 EB05 10.7 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 13.1 | no trial data cached |
| Cholestasis (bile flow blockage) | 13 | 18.4 10.7–31.5ROR 18.7 · χ² 197 / p 6e-45 | 17.5 EB05 10.3 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 13.1 | no trial data cached |
| Hyperbilirubinaemia | 7 | 18.3 8.8–38.4ROR 18.5 · χ² 98 / p 2e-23 | 15.8 EB05 6.5 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 13.2 | no trial data cached |
| Lymphopenia | 8 | 15.4 7.7–30.6ROR 15.5 · χ² 93 / p 2e-22 | 13.0 EB05 5.7 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.8 | no trial data cached |
| Hypoglycaemia (low blood sugar) | 25 | 13.9 9.5–20.5ROR 14.3 · χ² 287 / p 1e-64 | 13.4 EB05 9.2 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 10.2 | no trial data cached |
| Caesarean section | 6 | 13.8 6.2–30.6ROR 13.9 · χ² 59 / p 8e-15 | 10.2 EB05 4.0 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 10.0 | no trial data cached |
| Mucosal inflammation | 13 | 13.5 7.9–23.1ROR 13.7 · χ² 138 / p 4e-32 | 12.2 EB05 6.8 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 10.1 | no trial data cached |
| Neutrophil count increased | 5 | 13.1 5.5–31.5ROR 13.2 · χ² 45 / p 1e-11 | 8.8 EB05 3.3 · IC025 +1.1 3/3 methods agree | Lab value / disease marker | serious PRR 10.2 | no trial data cached |
| Pancytopenia (all blood cells low) | 24 | 11.6 7.8–17.2ROR 12.0 · χ² 223 / p 1e-50 | 10.9 EB05 7.4 · IC025 +2.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 7.9 · 95% clinician | no trial data cached |
| Cytomegalovirus infection | 7 | 11.4 5.4–23.8ROR 11.5 · χ² 56 / p 3e-14 | 8.3 EB05 3.8 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 8.1 | no trial data cached |
| Blood count abnormal | 5 | 8.8 3.7–21.0ROR 8.8 · χ² 27 / p 1e-7 | 5.6 EB05 2.5 · IC025 +0.8 3/3 methods agree | Lab value / disease marker | serious PRR 6.9 | no trial data cached |
| Expired product administered | 8 | 6.5 3.3–13.0ROR 6.6 · χ² 32 / p 8e-9 | 4.9 EB05 2.7 · IC025 +1.1 3/3 methods agree | Reporting / coding artifact | serious n=1 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
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 |
|---|---|---|---|---|---|---|
| Hypoglycaemia (low blood sugar) | 25 | 13.9 9.5–20.5ROR 14.3 · χ² 287 / p 1e-64 | 13.4 EB05 9.2 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 10.2 | no trial data cached |
| Pancytopenia (all blood cells low) | 24 | 11.6 7.8–17.2ROR 12.0 · χ² 223 / p 1e-50 | 10.9 EB05 7.4 · IC025 +2.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 7.9 · 95% clinician | no trial data cached |
| Hepatotoxicity (liver damage) | 24 | 29.2 19.7–43.4ROR 30.1 · χ² 627 / p 1e-138 | 28.6 EB05 20.2 · IC025 +3.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 20.2 · 100% clinician | no trial data cached |
| Bone marrow failure | 14 | 18.5 11.0–31.1ROR 18.8 · χ² 214 / p 8e-49 | 17.7 EB05 10.7 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 13.1 | no trial data cached |
| Mucosal inflammation | 13 | 13.5 7.9–23.1ROR 13.7 · χ² 138 / p 4e-32 | 12.2 EB05 6.8 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 10.1 | no trial data cached |
| Cholestasis (bile flow blockage) | 13 | 18.4 10.7–31.5ROR 18.7 · χ² 197 / p 6e-45 | 17.5 EB05 10.3 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 13.1 | no trial data cached |
| Hepatocellular injury | 10 | 19.0 10.3–35.2ROR 19.2 · χ² 153 / p 2e-35 | 17.7 EB05 9.3 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 13.4 | no trial data cached |
| Expired product administered | 8 | 6.5 3.3–13.0ROR 6.6 · χ² 32 / p 8e-9 | 4.9 EB05 2.7 · IC025 +1.1 3/3 methods agree | Reporting / coding artifact | serious n=1 | no trial data cached |
| Lymphopenia | 8 | 15.4 7.7–30.6ROR 15.5 · χ² 93 / p 2e-22 | 13.0 EB05 5.7 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.8 | no trial data cached |
| Cytomegalovirus infection | 7 | 11.4 5.4–23.8ROR 11.5 · χ² 56 / p 3e-14 | 8.3 EB05 3.8 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 8.1 | no trial data cached |
| Hyperbilirubinaemia | 7 | 18.3 8.8–38.4ROR 18.5 · χ² 98 / p 2e-23 | 15.8 EB05 6.5 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 13.2 | no trial data cached |
| Caesarean section | 6 | 13.8 6.2–30.6ROR 13.9 · χ² 59 / p 8e-15 | 10.2 EB05 4.0 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 10.0 | no trial data cached |
| Blood count abnormal | 5 | 8.8 3.7–21.0ROR 8.8 · χ² 27 / p 1e-7 | 5.6 EB05 2.5 · IC025 +0.8 3/3 methods agree | Lab value / disease marker | serious PRR 6.9 | no trial data cached |
| Neutrophil count increased | 5 | 13.1 5.5–31.5ROR 13.2 · χ² 45 / p 1e-11 | 8.8 EB05 3.3 · IC025 +1.1 3/3 methods agree | Lab value / disease marker | serious PRR 10.2 | no trial data cached |
| Myelosuppression | 4 | 3.2 1.2–8.4ROR 3.2 · χ² 4 / p 0.023 | 2.6 EB05 1.1 · IC025 -0.4 PRR-only: not supported by EBGM or IC | Labeled adverse reaction exact term | serious PRR 2.2 | 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.
- Hypoglycaemia — n=25, PRR 13.9
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 Purixan?
In FDA FAERS, the most frequently co-reported reaction terms for Purixan are hypoglycaemia, pancytopenia, hepatotoxicity, bone marrow failure, mucosal inflammation, cholestasis. 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 Purixan have an FDA boxed warning?
No. The FDA label retrieved for Purixan has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Purixan 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 9fd27952-7787-47d9-b6cf-7af2dc38217b, effective 20260720; matched on
openfda.generic_name.exact:"PURIXAN") - 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, 18 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.