Pentostatin side effects: what 1,048 FDA adverse event reports show

Pentostatin · Nipent · 38 reaction terms · 644 drug–reaction co-reports · data 2026-09-14

Drug class

Nucleoside Metabolic Inhibitor

FDA label (Established Pharmacologic Class) · compare the class

Brand names

Nipent

openFDA label

Who reports

1,048 reports · 92% serious · 255 with death outcome · 35% female

openFDA FAERS counts, all years, deduplication not applied

Used for

NIPENT is indicated as single-agent treatment for both untreated and alpha-interferon-refractory hairy cell leukemia patients with active disease as defined by clinically significant anemia, neutropenia, thrombocytopenia, or disease-related symptoms.

FDA label, Indications and Usage

What it is

DESCRIPTION NIPENT ™ (pentostatin for injection) is supplied as a sterile, apyrogenic, lyophilized powder in single-dose vials for intravenous administration.

FDA label, Description section

Boxed warning

NIPENT should be administered under the supervision of a physician qualified and experienced in the use of cancer chemotherapeutic agents. The use of higher doses than those specified (see DOSAGE AND ADMINISTRATION ) is not recommended.

FDA 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 24 strongest signals

Labeled — boxed warning 4Labeled (related wording) 5Likely indication confounding 3Lab value / disease marker 2Not in label — unassessed 10

What the badges mean

Labeled — boxed warning The term (or its clinical synonym) appears in the FDA boxed warning: causality is regulator-recognised and considered serious.
Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
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. 14 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.

Show: hide coding/lab/outcome terms hide indication terms unlabeled only hide PRR-only

Reaction	Reports	PRR 95% CI · ROR · χ²/p	EBGM EB05 · IC025	Label screen	Serious-only & strata	Trial cross-check
Thrombotic microangiopathy	25	51.8 35.1–76.3ROR 53.0 · χ² 1,192 / p 2e-261	49.8 EB05 35.5 · IC025 +4.0 3/3 methods agree	Not in label — unassessed	serious PRR 32.3 · ♀ 0% (drug 35%) · 100% clinician	no trial data cached
Lymphopenia	27	38.5 26.5–55.8ROR 39.5 · χ² 947 / p 3e-208	37.5 EB05 27.0 · IC025 +3.9 3/3 methods agree	Not in label — unassessed	serious PRR 16.3 · ♀ 12% (drug 35%)	no trial data cached
Atelectasis	11	22.7 12.6–40.9ROR 23.0 · χ² 207 / p 3e-47	21.7 EB05 12.5 · IC025 +2.5 3/3 methods agree	Not in label — unassessed	serious PRR 14.4	no trial data cached
Cytopenia	13	21.8 12.7–37.4ROR 22.0 · χ² 237 / p 8e-54	21.0 EB05 12.7 · IC025 +2.7 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 14.1	no trial data cached
Neutrophil count decreased	42	20.8 15.4–27.9ROR 21.6 · χ² 771 / p 5e-170	20.6 EB05 15.8 · IC025 +3.6 3/3 methods agree	Labeled — boxed warning synonym match	serious PRR 11.5 · 100% clinician	no trial data cached
Myelodysplastic syndrome	15	20.8 12.6–34.3ROR 21.0 · χ² 263 / p 2e-59	20.1 EB05 12.7 · IC025 +2.8 3/3 methods agree	Not in label — unassessed	serious PRR 12.2	no trial data cached
Acute myeloid leukaemia	16	20.6 12.7–33.5ROR 20.9 · χ² 279 / p 7e-63	20.0 EB05 12.8 · IC025 +2.8 3/3 methods agree	Likely indication confounding shares a disease stem with the indications wording	serious PRR 12.9	no trial data cached
Body temperature increased	17	16.6 10.4–26.6ROR 16.9 · χ² 234 / p 3e-53	16.0 EB05 10.1 · IC025 +2.7 3/3 methods agree	Lab value / disease marker	serious PRR 12.1	no trial data cached
Multi-organ failure	14	16.0 9.5–26.9ROR 16.2 · χ² 182 / p 9e-42	15.1 EB05 8.8 · IC025 +2.5 3/3 methods agree	Not in label — unassessed	serious PRR 10.0	no trial data cached
Acute respiratory distress syndrome	13	14.7 8.6–25.3ROR 14.9 · χ² 153 / p 2e-35	13.6 EB05 7.6 · IC025 +2.3 3/3 methods agree	Not in label — unassessed	serious PRR 9.2	no trial data cached
Febrile neutropenia	47	14.2 10.7–18.8ROR 14.8 · χ² 565 / p 3e-125	14.0 EB05 10.8 · IC025 +3.2 3/3 methods agree	Labeled — boxed warning synonym match	serious PRR 8.5 · ♀ 12% (drug 35%) · 97% clinician	no trial data cached
Pancytopenia (all blood cells low)	38	13.7 10.0–18.7ROR 14.1 · χ² 434 / p 1e-96	13.4 EB05 10.0 · IC025 +3.0 3/3 methods agree	Labeled (related wording) related wording	serious PRR 8.4 · 97% clinician	no trial data cached
Cytomegalovirus infection	11	13.2 7.4–23.8ROR 13.4 · χ² 113 / p 1e-26	11.5 EB05 6.0 · IC025 +2.1 3/3 methods agree	Not in label — unassessed	serious PRR 8.4	no trial data cached
Lung infection	10	12.7 6.9–23.5ROR 12.8 · χ² 96 / p 5e-23	10.7 EB05 5.4 · IC025 +2.0 3/3 methods agree	Labeled (related wording) related wording	serious PRR 8.5	no trial data cached
Pneumonitis	17	12.6 7.9–20.2ROR 12.8 · χ² 170 / p 4e-39	11.6 EB05 7.1 · IC025 +2.4 3/3 methods agree	Not in label — unassessed	serious PRR 8.2	no trial data cached
Lymphocyte count decreased	10	11.3 6.1–21.0ROR 11.4 · χ² 84 / p 2e-20	9.2 EB05 4.8 · IC025 +1.8 3/3 methods agree	Lab value / disease marker	serious PRR 5.2	no trial data cached
Neutropenia (low neutrophils (infection-fighting cells))	76	11.2 9.0–13.9ROR 12.0 · χ² 702 / p 5e-155	11.0 EB05 9.0 · IC025 +3.0 3/3 methods agree	Labeled — boxed warning exact term	serious PRR 6.5 · 95% clinician	no trial data cached
Renal failure acute	24	11.2 7.5–16.6ROR 11.4 · χ² 212 / p 2e-48	10.4 EB05 7.0 · IC025 +2.5 3/3 methods agree	Labeled (related wording) related wording	serious PRR 7.0 · 95% clinician	no trial data cached
Cholestasis (bile flow blockage)	10	10.5 5.7–19.4ROR 10.6 · χ² 77 / p 1e-18	8.4 EB05 4.4 · IC025 +1.8 3/3 methods agree	Not in label — unassessed	serious PRR 5.3	no trial data cached
Pulmonary oedema	23	10.3 6.9–15.4ROR 10.5 · χ² 184 / p 4e-42	9.4 EB05 6.3 · IC025 +2.4 3/3 methods agree	Labeled — boxed warning exact term	serious PRR 6.2	no trial data cached
Lymphadenopathy	18	10.2 6.4–16.1ROR 10.3 · χ² 140 / p 1e-32	9.0 EB05 5.7 · IC025 +2.2 3/3 methods agree	Not in label — unassessed	serious PRR 8.3	no trial data cached
Bone marrow failure	10	9.8 5.3–18.1ROR 9.9 · χ² 70 / p 2e-17	7.7 EB05 4.2 · IC025 +1.7 3/3 methods agree	Labeled (related wording) related wording	serious PRR 5.5	no trial data cached
Thrombocytopenia (low platelets)	54	9.7 7.5–12.6ROR 10.2 · χ² 414 / p 2e-92	9.3 EB05 7.3 · IC025 +2.7 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 5.9 · 96% clinician	no trial data cached
Hepatic failure	14	9.3 5.5–15.6ROR 9.4 · χ² 95 / p 8e-23	7.8 EB05 4.7 · IC025 +1.9 3/3 methods agree	Labeled (related wording) related wording	serious PRR 5.8	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
Neutropenia (low neutrophils (infection-fighting cells))	76	11.2 9.0–13.9ROR 12.0 · χ² 702 / p 5e-155	11.0 EB05 9.0 · IC025 +3.0 3/3 methods agree	Labeled — boxed warning exact term	serious PRR 6.5 · 95% clinician	no trial data cached
Thrombocytopenia (low platelets)	54	9.7 7.5–12.6ROR 10.2 · χ² 414 / p 2e-92	9.3 EB05 7.3 · IC025 +2.7 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 5.9 · 96% clinician	no trial data cached
Febrile neutropenia	47	14.2 10.7–18.8ROR 14.8 · χ² 565 / p 3e-125	14.0 EB05 10.8 · IC025 +3.2 3/3 methods agree	Labeled — boxed warning synonym match	serious PRR 8.5 · ♀ 12% (drug 35%) · 97% clinician	no trial data cached
Neutrophil count decreased	42	20.8 15.4–27.9ROR 21.6 · χ² 771 / p 5e-170	20.6 EB05 15.8 · IC025 +3.6 3/3 methods agree	Labeled — boxed warning synonym match	serious PRR 11.5 · 100% clinician	no trial data cached
Pancytopenia (all blood cells low)	38	13.7 10.0–18.7ROR 14.1 · χ² 434 / p 1e-96	13.4 EB05 10.0 · IC025 +3.0 3/3 methods agree	Labeled (related wording) related wording	serious PRR 8.4 · 97% clinician	no trial data cached
Lymphopenia	27	38.5 26.5–55.8ROR 39.5 · χ² 947 / p 3e-208	37.5 EB05 27.0 · IC025 +3.9 3/3 methods agree	Not in label — unassessed	serious PRR 16.3 · ♀ 12% (drug 35%)	no trial data cached
Thrombotic microangiopathy	25	51.8 35.1–76.3ROR 53.0 · χ² 1,192 / p 2e-261	49.8 EB05 35.5 · IC025 +4.0 3/3 methods agree	Not in label — unassessed	serious PRR 32.3 · ♀ 0% (drug 35%) · 100% clinician	no trial data cached
Renal failure acute	24	11.2 7.5–16.6ROR 11.4 · χ² 212 / p 2e-48	10.4 EB05 7.0 · IC025 +2.5 3/3 methods agree	Labeled (related wording) related wording	serious PRR 7.0 · 95% clinician	no trial data cached
Pulmonary oedema	23	10.3 6.9–15.4ROR 10.5 · χ² 184 / p 4e-42	9.4 EB05 6.3 · IC025 +2.4 3/3 methods agree	Labeled — boxed warning exact term	serious PRR 6.2	no trial data cached
Lymphadenopathy	18	10.2 6.4–16.1ROR 10.3 · χ² 140 / p 1e-32	9.0 EB05 5.7 · IC025 +2.2 3/3 methods agree	Not in label — unassessed	serious PRR 8.3	no trial data cached
Pneumonitis	17	12.6 7.9–20.2ROR 12.8 · χ² 170 / p 4e-39	11.6 EB05 7.1 · IC025 +2.4 3/3 methods agree	Not in label — unassessed	serious PRR 8.2	no trial data cached
Body temperature increased	17	16.6 10.4–26.6ROR 16.9 · χ² 234 / p 3e-53	16.0 EB05 10.1 · IC025 +2.7 3/3 methods agree	Lab value / disease marker	serious PRR 12.1	no trial data cached
Acute myeloid leukaemia	16	20.6 12.7–33.5ROR 20.9 · χ² 279 / p 7e-63	20.0 EB05 12.8 · IC025 +2.8 3/3 methods agree	Likely indication confounding shares a disease stem with the indications wording	serious PRR 12.9	no trial data cached
Myelodysplastic syndrome	15	20.8 12.6–34.3ROR 21.0 · χ² 263 / p 2e-59	20.1 EB05 12.7 · IC025 +2.8 3/3 methods agree	Not in label — unassessed	serious PRR 12.2	no trial data cached
Hepatic failure	14	9.3 5.5–15.6ROR 9.4 · χ² 95 / p 8e-23	7.8 EB05 4.7 · IC025 +1.9 3/3 methods agree	Labeled (related wording) related wording	serious PRR 5.8	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.

Thrombotic microangiopathy — n=25, PRR 51.8
Lymphopenia — n=27, PRR 38.5

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 Pentostatin?

In FDA FAERS, the most frequently co-reported reaction terms for Pentostatin are neutropenia, thrombocytopenia, febrile neutropenia, neutrophil count decreased, pancytopenia, lymphopenia. 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 Pentostatin have an FDA boxed warning?

Yes. The current FDA label carries a boxed warning: NIPENT should be administered under the supervision of a physician qualified and experienced in the use of cancer chemotherapeutic agents. The use of higher doses than those specified (see DOSAGE AND ADMINISTRATION ) is not recommended.

Do FAERS signals prove that Pentostatin 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 674e0e6d-46ed-4868-9196-04019d667716, effective 20260701; matched on openfda.generic_name.exact:"PENTOSTATIN")
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, field patient.drug.openfda.generic_name.exact, 38 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.