Toremifene side effects: what 429 FDA adverse event reports show
Drug class
Not stated in label
Label matched
Toremifene Citrate (Toremifene Citrate)
Who reports
429 reports · 87% serious · 56 with death outcome · 94% female
Used for
Toremifene citrate tablets are estrogen agonist/antagonist indicated for the treatment of metastatic breast cancer in postmenopausal women with estrogen-receptor positive or unknown tumors. Toremifene citrate tablets are estrogen agonist/antagonist indicated for the treatment of metastatic breast cancer in postmenopausal women with estrogen-receptor positive or unknown tumors.
What it is
Toremifene citrate tablets for oral administration each contain 88.5 mg of toremifene citrate, which is equivalent to 60 mg toremifene. Toremifene citrate tablets are estrogen agonist/antagonist.
Boxed warning
QT PROLONGATION Toremifene citrate has been shown to prolong the QTc interval in a dose- and concentration-related manner [see Clinical Pharmacology (12.2)]. Prolongation of the QT interval can result in a type of ventricular tachycardia called Torsade de pointes, which may result in syncope, seizure, and/or death.
Causality screen of the 10 strongest signals
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.
- 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 |
|---|---|---|---|---|---|---|
| Osteomyelitis | 16 | 43.4 26.8–70.1ROR 45.0 · χ² 620 / p 3e-137 | 41.4 EB05 27.0 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 29.2 | no trial data cached |
| Tooth extraction | 10 | 39.4 21.3–72.7ROR 40.3 · χ² 337 / p 2e-75 | 36.8 EB05 21.3 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 35.8 | no trial data cached |
| Osteonecrosis of jaw (jawbone death) | 19 | 37.4 24.1–58.0ROR 39.1 · χ² 637 / p 7e-141 | 36.1 EB05 24.4 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 24.8 | no trial data cached |
| Blood lactate dehydrogenase increased | 10 | 30.7 16.7–56.7ROR 31.5 · χ² 259 / p 2e-58 | 29.1 EB05 16.8 · IC025 +2.6 3/3 methods agree | Lab value / disease marker | serious PRR 21.7 | no trial data cached |
| Metastases to bone | 10 | 30.0 16.2–55.3ROR 30.7 · χ² 252 / p 5e-57 | 28.4 EB05 16.3 · IC025 +2.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 18.1 | no trial data cached |
| Hepatic function abnormal | 22 | 29.1 19.4–43.7ROR 30.6 · χ² 570 / p 3e-126 | 28.4 EB05 19.8 · IC025 +3.4 3/3 methods agree | Labeled (related wording) related wording | serious PRR 18.9 | no trial data cached |
| Metastases to liver | 8 | 22.4 11.3–44.4ROR 22.8 · χ² 143 / p 4e-33 | 20.6 EB05 10.0 · IC025 +2.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 14.9 | no trial data cached |
| Interstitial lung disease | 22 | 22.3 14.9–33.5ROR 23.5 · χ² 428 / p 3e-95 | 21.9 EB05 15.2 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 14.9 | no trial data cached |
| Osteonecrosis (bone death) | 11 | 16.3 9.1–29.1ROR 16.7 · χ² 143 / p 3e-33 | 15.0 EB05 7.9 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 10.8 | no trial data cached |
| Breast cancer | 9 | 4.7 2.5–8.9ROR 4.8 · χ² 23 / p 1e-6 | 3.9 EB05 2.2 · IC025 +0.8 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 3.1 | 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 |
|---|---|---|---|---|---|---|
| Interstitial lung disease | 22 | 22.3 14.9–33.5ROR 23.5 · χ² 428 / p 3e-95 | 21.9 EB05 15.2 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 14.9 | no trial data cached |
| Hepatic function abnormal | 22 | 29.1 19.4–43.7ROR 30.6 · χ² 570 / p 3e-126 | 28.4 EB05 19.8 · IC025 +3.4 3/3 methods agree | Labeled (related wording) related wording | serious PRR 18.9 | no trial data cached |
| Osteonecrosis of jaw (jawbone death) | 19 | 37.4 24.1–58.0ROR 39.1 · χ² 637 / p 7e-141 | 36.1 EB05 24.4 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 24.8 | no trial data cached |
| Osteomyelitis | 16 | 43.4 26.8–70.1ROR 45.0 · χ² 620 / p 3e-137 | 41.4 EB05 27.0 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 29.2 | no trial data cached |
| Osteonecrosis (bone death) | 11 | 16.3 9.1–29.1ROR 16.7 · χ² 143 / p 3e-33 | 15.0 EB05 7.9 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 10.8 | no trial data cached |
| Metastases to bone | 10 | 30.0 16.2–55.3ROR 30.7 · χ² 252 / p 5e-57 | 28.4 EB05 16.3 · IC025 +2.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 18.1 | no trial data cached |
| Blood lactate dehydrogenase increased | 10 | 30.7 16.7–56.7ROR 31.5 · χ² 259 / p 2e-58 | 29.1 EB05 16.8 · IC025 +2.6 3/3 methods agree | Lab value / disease marker | serious PRR 21.7 | no trial data cached |
| Tooth extraction | 10 | 39.4 21.3–72.7ROR 40.3 · χ² 337 / p 2e-75 | 36.8 EB05 21.3 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 35.8 | no trial data cached |
| Breast cancer | 9 | 4.7 2.5–8.9ROR 4.8 · χ² 23 / p 1e-6 | 3.9 EB05 2.2 · IC025 +0.8 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 3.1 | no trial data cached |
| Metastases to liver | 8 | 22.4 11.3–44.4ROR 22.8 · χ² 143 / p 4e-33 | 20.6 EB05 10.0 · IC025 +2.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 14.9 | no trial data cached |
| Myelosuppression | 4 | 5.8 2.2–15.3ROR 5.8 · χ² 11 / p 4e-4 | 3.8 EB05 1.7 · IC025 +0.1 | Not in label — unassessed | serious PRR 3.8 | no trial data cached |
| Palmar-plantar erythrodysaesthesia syndrome | 4 | 8.4 3.2–22.2ROR 8.4 · χ² 19 / p 6e-6 | 5.0 EB05 2.0 · IC025 +0.4 3/3 methods agree | Not in label — unassessed | serious PRR 7.4 | no trial data cached |
| Genital haemorrhage | 4 | 15.1 5.7–40.2ROR 15.3 · χ² 40 / p 2e-10 | 9.5 EB05 3.0 · IC025 +0.8 3/3 methods agree | Not in label — unassessed | serious PRR 15.6 | no trial data cached |
| Breast cancer metastatic | 3 | 13.7 4.4–42.3ROR 13.8 · χ² 24 / p 5e-7 | 7.0 EB05 2.1 · IC025 +0.2 3/3 methods agree | Likely indication confounding term in indications | serious PRR 6.2 | 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.
- Interstitial lung disease — n=22, PRR 22.3
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 Toremifene?
In FDA FAERS, the most frequently co-reported reaction terms for Toremifene are interstitial lung disease, hepatic function abnormal, osteonecrosis of jaw, osteomyelitis, osteonecrosis, metastases to bone. 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 Toremifene have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: QT PROLONGATION Toremifene citrate has been shown to prolong the QTc interval in a dose- and concentration-related manner [see Clinical Pharmacology (12.2)]. Prolongation of the QT interval can result in a type of ventricular tachycardia called Torsade de pointes, which may result in syncope, seizure, and/or death.
Do FAERS signals prove that Toremifene 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 e897546b-4136-4cb5-a262-d94cf3fa3298, effective 20250919; matched on
openfda.generic_name.exact:"TOREMIFENE CITRATE") - 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, 14 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.