Anagrelide side effects: what 1,140 FDA adverse event reports show

Anagrelide · 45 reaction terms · 620 drug–reaction co-reports · data 2026-09-14

Drug class

Platelet reducing agent

FDA label, Indications wording

Who reports

1,140 reports · 68% serious · 111 with death outcome · 58% female

openFDA FAERS counts, all years, deduplication not applied

Used for

Anagrelide capsules are indicated for the treatment of patients with thrombocythemia, secondary to myeloproliferative neoplasms, to reduce the elevated platelet count and the risk of thrombosis and to ameliorate associated symptoms including thrombo-hemorrhagic events.

FDA label, Indications and Usage

What it is

Anagrelide Hydrochloride, USP is a platelet-reducing agent.

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 17 strongest signals

Labeled (related wording) 2Likely indication confounding 1Reporting / coding artifact 4Lab value / disease marker 5Not in label — unassessed 5

What the badges mean

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.
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. 28 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
Platelet count increased	102	144.7 120.2–174.3ROR 158.9 · χ² 14,310 / p <1e-300	139.9 EB05 118.5 · IC025 +6.1 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 98.5	no trial data cached
Splenomegaly	27	42.5 29.3–61.7ROR 43.5 · χ² 1,051 / p 6e-231	41.3 EB05 29.8 · IC025 +4.0 3/3 methods agree	Not in label — unassessed	serious PRR 32.7	no trial data cached
Blood potassium increased	15	17.0 10.3–28.1ROR 17.2 · χ² 210 / p 6e-48	16.3 EB05 9.9 · IC025 +2.6 3/3 methods agree	Lab value / disease marker	serious PRR 11.2	no trial data cached
Blood count abnormal	14	16.8 10.0–28.2ROR 17.0 · χ² 192 / p 6e-44	15.9 EB05 9.4 · IC025 +2.5 3/3 methods agree	Lab value / disease marker	serious PRR 8.5	no trial data cached
Haematocrit decreased	18	16.6 10.5–26.3ROR 16.8 · χ² 248 / p 3e-56	16.0 EB05 10.3 · IC025 +2.8 3/3 methods agree	Lab value / disease marker	serious PRR 8.7	no trial data cached
Skin ulcer	23	16.4 10.9–24.6ROR 16.7 · χ² 317 / p 3e-71	16.0 EB05 11.0 · IC025 +2.9 3/3 methods agree	Not in label — unassessed	serious PRR 12.8	no trial data cached
White blood cell count increased	30	14.3 10.1–20.4ROR 14.7 · χ² 359 / p 2e-80	14.0 EB05 10.0 · IC025 +2.9 3/3 methods agree	Lab value / disease marker	serious PRR 8.2 · 70% consumer	no trial data cached
Haemoglobin decreased	73	13.1 10.5–16.3ROR 13.9 · χ² 804 / p 3e-177	12.9 EB05 10.5 · IC025 +3.2 3/3 methods agree	Labeled (related wording) related wording	serious PRR 8.5	no trial data cached
Acute myocardial infarction	20	12.4 8.1–19.2ROR 12.6 · χ² 199 / p 2e-45	11.6 EB05 7.5 · IC025 +2.5 3/3 methods agree	Labeled (related wording) related wording	serious PRR 10.5 · 100% clinician	no trial data cached
Red blood cell count decreased	18	11.6 7.3–18.3ROR 11.7 · χ² 164 / p 1e-37	10.5 EB05 6.6 · IC025 +2.4 3/3 methods agree	Lab value / disease marker	serious PRR 7.1	no trial data cached
Haemoptysis	14	9.2 5.5–15.5ROR 9.3 · χ² 95 / p 1e-22	7.7 EB05 4.7 · IC025 +1.9 3/3 methods agree	Not in label — unassessed	serious PRR 8.7	no trial data cached
Transient ischaemic attack (mini-stroke)	15	8.1 4.9–13.5ROR 8.2 · χ² 87 / p 5e-21	6.9 EB05 4.3 · IC025 +1.9 3/3 methods agree	Not in label — unassessed	serious PRR 6.0	no trial data cached
Sedation	11	7.8 4.3–14.0ROR 7.8 · χ² 58 / p 1e-14	6.2 EB05 3.6 · IC025 +1.6 3/3 methods agree	Not in label — unassessed	serious PRR 9.0	no trial data cached
Impaired healing	13	7.3 4.2–12.5ROR 7.4 · χ² 64 / p 5e-16	6.0 EB05 3.7 · IC025 +1.6 3/3 methods agree	Reporting / coding artifact	serious PRR 4.0	no trial data cached
Drug resistance	10	7.2 3.9–13.3ROR 7.2 · χ² 47 / p 3e-12	5.6 EB05 3.2 · IC025 +1.4 3/3 methods agree	Reporting / coding artifact	serious PRR 6.8	no trial data cached
Product dose omission	15	4.2 2.5–6.9ROR 4.2 · χ² 33 / p 4e-9	3.7 EB05 2.4 · IC025 +1.0 3/3 methods agree	Reporting / coding artifact	serious PRR 7.6	no trial data cached
Drug dose omission	28	3.1 2.1–4.4ROR 3.1 · χ² 37 / p 5e-10	3.0 EB05 2.2 · IC025 +0.9 3/3 methods agree	Reporting / coding artifact	serious PRR 4.4	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
Platelet count increased	102	144.7 120.2–174.3ROR 158.9 · χ² 14,310 / p <1e-300	139.9 EB05 118.5 · IC025 +6.1 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 98.5	no trial data cached
Haemoglobin decreased	73	13.1 10.5–16.3ROR 13.9 · χ² 804 / p 3e-177	12.9 EB05 10.5 · IC025 +3.2 3/3 methods agree	Labeled (related wording) related wording	serious PRR 8.5	no trial data cached
White blood cell count increased	30	14.3 10.1–20.4ROR 14.7 · χ² 359 / p 2e-80	14.0 EB05 10.0 · IC025 +2.9 3/3 methods agree	Lab value / disease marker	serious PRR 8.2 · 70% consumer	no trial data cached
Drug dose omission	28	3.1 2.1–4.4ROR 3.1 · χ² 37 / p 5e-10	3.0 EB05 2.2 · IC025 +0.9 3/3 methods agree	Reporting / coding artifact	serious PRR 4.4	no trial data cached
Splenomegaly	27	42.5 29.3–61.7ROR 43.5 · χ² 1,051 / p 6e-231	41.3 EB05 29.8 · IC025 +4.0 3/3 methods agree	Not in label — unassessed	serious PRR 32.7	no trial data cached
Skin ulcer	23	16.4 10.9–24.6ROR 16.7 · χ² 317 / p 3e-71	16.0 EB05 11.0 · IC025 +2.9 3/3 methods agree	Not in label — unassessed	serious PRR 12.8	no trial data cached
Acute myocardial infarction	20	12.4 8.1–19.2ROR 12.6 · χ² 199 / p 2e-45	11.6 EB05 7.5 · IC025 +2.5 3/3 methods agree	Labeled (related wording) related wording	serious PRR 10.5 · 100% clinician	no trial data cached
Red blood cell count decreased	18	11.6 7.3–18.3ROR 11.7 · χ² 164 / p 1e-37	10.5 EB05 6.6 · IC025 +2.4 3/3 methods agree	Lab value / disease marker	serious PRR 7.1	no trial data cached
Haematocrit decreased	18	16.6 10.5–26.3ROR 16.8 · χ² 248 / p 3e-56	16.0 EB05 10.3 · IC025 +2.8 3/3 methods agree	Lab value / disease marker	serious PRR 8.7	no trial data cached
Product dose omission	15	4.2 2.5–6.9ROR 4.2 · χ² 33 / p 4e-9	3.7 EB05 2.4 · IC025 +1.0 3/3 methods agree	Reporting / coding artifact	serious PRR 7.6	no trial data cached
Transient ischaemic attack (mini-stroke)	15	8.1 4.9–13.5ROR 8.2 · χ² 87 / p 5e-21	6.9 EB05 4.3 · IC025 +1.9 3/3 methods agree	Not in label — unassessed	serious PRR 6.0	no trial data cached
Blood potassium increased	15	17.0 10.3–28.1ROR 17.2 · χ² 210 / p 6e-48	16.3 EB05 9.9 · IC025 +2.6 3/3 methods agree	Lab value / disease marker	serious PRR 11.2	no trial data cached
Haemoptysis	14	9.2 5.5–15.5ROR 9.3 · χ² 95 / p 1e-22	7.7 EB05 4.7 · IC025 +1.9 3/3 methods agree	Not in label — unassessed	serious PRR 8.7	no trial data cached
Blood count abnormal	14	16.8 10.0–28.2ROR 17.0 · χ² 192 / p 6e-44	15.9 EB05 9.4 · IC025 +2.5 3/3 methods agree	Lab value / disease marker	serious PRR 8.5	no trial data cached
Impaired healing	13	7.3 4.2–12.5ROR 7.4 · χ² 64 / p 5e-16	6.0 EB05 3.7 · IC025 +1.6 3/3 methods agree	Reporting / coding artifact	serious PRR 4.0	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.

Splenomegaly — n=27, PRR 42.5
Skin ulcer — n=23, PRR 16.4

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 Anagrelide?

In FDA FAERS, the most frequently co-reported reaction terms for Anagrelide are platelet count increased, haemoglobin decreased, white blood cell count increased, splenomegaly, skin ulcer, acute myocardial infarction. 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 Anagrelide have an FDA boxed warning?

No. The FDA label retrieved for Anagrelide has no boxed warning; see the label's Warnings and Precautions for the recognised risks.

Do FAERS signals prove that Anagrelide 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 e031dfb3-56e1-4fea-95f2-c2936e2057a0, effective 20240307; matched on openfda.generic_name.exact:"ANAGRELIDE")
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, 45 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.