Drug · FAERS side-effect profile with label screen
Imiquimod side effects: what 2,291 FDA adverse event reports show
Drug class
Interferon Inducers
FDA label (mechanism-of-action class)
Who reports
2,291 reports · 55% serious · 73 with death outcome · 50% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Imiquimod Cream USP, 5% is indicated for the topical treatment of: Clinically typical, nonhyperkeratotic, nonhypertrophic actinic keratoses (AK) on the face or scalp in immunocompetent adults ( 1.1 ). Biopsy-confirmed, primary superficial basal cell ca.
FDA label, Indications and Usage
What it is
Imiquimod Cream USP, 5% is an immune response modifier for topical administration. Each gram contains 50 mg of imiquimod in an off-white oil-in-water vanishing cream base consisting of benzyl .
FDA label, Description section
Boxed warning
Important: For use on the skin only (topical). Do not use Imiquimod Cream in or near your mouth, eyes, nose or vagina.
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 40 strongest signals
Labeled adverse reaction 8Labeled (related wording) 13Likely indication confounding 2Reporting / coding artifact 8Not in label — unassessed 9
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.
- 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.
- 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. 46 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Scab | 76 | 61.7 49.5–77.1ROR 63.8 · χ² 4,453 / p <1e-300 | 60.4 EB05 49.9 · IC025 +5.1 3/3 methods agree | Labeled adverse reaction exact term | serious n=38 | no trial data cached |
| Application site erythema | 100 | 34.9 28.8–42.3ROR 36.4 · χ² 3,250 / p <1e-300 | 34.6 EB05 29.2 · IC025 +4.6 3/3 methods agree | Labeled (related wording) related wording | serious n=30 | no trial data cached |
| Application site pain | 73 | 30.4 24.3–38.2ROR 31.4 · χ² 2,044 / p <1e-300 | 30.1 EB05 24.8 · IC025 +4.3 3/3 methods agree | Labeled (related wording) related wording | serious n=15 · 86% consumer | no trial data cached |
| Skin reaction | 38 | 24.8 18.1–34.0ROR 25.2 · χ² 841 / p 3e-185 | 24.4 EB05 18.6 · IC025 +3.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 39.3 | no trial data cached |
| Erythema multiforme | 20 | 19.7 12.7–30.4ROR 19.8 · χ² 335 / p 3e-75 | 19.2 EB05 13.0 · IC025 +3.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 19.1 | no trial data cached |
| Basal cell carcinoma | 32 | 18.8 13.3–26.5ROR 19.0 · χ² 520 / p 2e-115 | 18.5 EB05 13.7 · IC025 +3.3 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 18.3 | no trial data cached |
| Application site irritation | 25 | 18.4 12.5–27.2ROR 18.6 · χ² 394 / p 6e-88 | 18.1 EB05 12.7 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | serious n=7 | no trial data cached |
| Therapy partial responder | 30 | 18.3 12.8–26.1ROR 18.5 · χ² 472 / p 7e-105 | 18.0 EB05 13.1 · IC025 +3.2 3/3 methods agree | Reporting / coding artifact | serious PRR 18.5 · 97% clinician | no trial data cached |
| Skin ulcer | 49 | 17.4 13.2–23.0ROR 17.8 · χ² 740 / p 3e-163 | 17.2 EB05 13.5 · IC025 +3.4 3/3 methods agree | Labeled (related wording) related wording | serious PRR 11.8 · ♀ 73% (drug 50%) | no trial data cached |
| Squamous cell carcinoma | 17 | 16.5 10.3–26.6ROR 16.6 · χ² 232 / p 9e-53 | 15.9 EB05 10.0 · IC025 +2.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 16.7 | no trial data cached |
| Application site pruritus | 33 | 13.3 9.5–18.7ROR 13.5 · χ² 364 / p 2e-81 | 12.9 EB05 9.4 · IC025 +2.9 3/3 methods agree | Labeled (related wording) related wording | serious n=7 · 81% consumer | no trial data cached |
| Pemphigus | 18 | 13.3 8.4–21.0ROR 13.4 · χ² 192 / p 6e-44 | 12.4 EB05 7.7 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 13.9 | no trial data cached |
| Influenza like illness (flu-like illness) | 102 | 11.3 9.4–13.7ROR 11.8 · χ² 950 / p 6e-209 | 11.1 EB05 9.4 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 12.6 | no trial data cached |
| Product packaging quantity issue | 13 | 10.9 6.3–18.8ROR 11.0 · χ² 107 / p 2e-25 | 9.3 EB05 5.3 · IC025 +2.1 3/3 methods agree | Reporting / coding artifact | – | no trial data cached |
| Skin lesion | 30 | 10.1 7.1–14.4ROR 10.2 · χ² 237 / p 1e-53 | 9.4 EB05 6.7 · IC025 +2.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 10.8 | no trial data cached |
| Drug resistance | 28 | 10.0 6.9–14.4ROR 10.1 · χ² 217 / p 2e-49 | 9.2 EB05 6.5 · IC025 +2.5 3/3 methods agree | Reporting / coding artifact | serious PRR 11.3 · 100% clinician | no trial data cached |
| Economic problem | 16 | 9.5 5.8–15.5ROR 9.6 · χ² 113 / p 9e-27 | 8.2 EB05 5.1 · IC025 +2.1 3/3 methods agree | Reporting / coding artifact | serious PRR 10.2 | no trial data cached |
| Skin irritation | 47 | 9.4 7.1–12.4ROR 9.6 · χ² 344 / p 5e-77 | 8.9 EB05 6.9 · IC025 +2.6 3/3 methods agree | Labeled (related wording) related wording | serious n=6 · ♀ 78% (drug 50%) · 94% clinician | no trial data cached |
| Drug ineffective for unapproved indication | 55 | 9.0 7.0–11.7ROR 9.2 · χ² 386 / p 4e-86 | 8.6 EB05 6.8 · IC025 +2.6 3/3 methods agree | Reporting / coding artifact | serious PRR 11.1 | no trial data cached |
| Anhedonia | 25 | 8.6 5.9–12.8ROR 8.7 · χ² 161 / p 3e-37 | 7.8 EB05 5.4 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 9.6 · ♀ 8% (drug 50%) | no trial data cached |
| Erythema (skin redness) | 183 | 8.2 7.1–9.4ROR 8.8 · χ² 1,153 / p 5e-253 | 8.0 EB05 7.1 · IC025 +2.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.8 | no trial data cached |
| Ulcer | 13 | 7.5 4.3–12.8ROR 7.5 · χ² 67 / p 2e-16 | 6.1 EB05 3.8 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.3 | no trial data cached |
| Stevens-johnson syndrome (severe blistering skin reaction) | 18 | 7.4 4.7–11.7ROR 7.4 · χ² 93 / p 2e-22 | 6.4 EB05 4.2 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 7.8 | no trial data cached |
| Oedema | 42 | 7.1 5.3–9.6ROR 7.2 · χ² 215 / p 7e-49 | 6.7 EB05 5.1 · IC025 +2.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 1.8 · 93% clinician | no trial data cached |
| Lip swelling | 24 | 6.6 4.4–9.8ROR 6.7 · χ² 109 / p 9e-26 | 5.9 EB05 4.2 · IC025 +1.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.7 · ♀ 85% (drug 50%) | no trial data cached |
| Osteopenia | 11 | 6.6 3.7–11.9ROR 6.6 · χ² 47 / p 4e-12 | 5.3 EB05 3.2 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 8.1 | no trial data cached |
| Product administered at inappropriate site | 13 | 6.6 3.8–11.3ROR 6.6 · χ² 56 / p 4e-14 | 5.4 EB05 3.4 · IC025 +1.5 3/3 methods agree | Reporting / coding artifact | – | no trial data cached |
| Product use in unapproved indication | 174 | 6.5 5.7–7.5ROR 7.0 · χ² 817 / p 6e-180 | 6.4 EB05 5.7 · IC025 +2.4 3/3 methods agree | Reporting / coding artifact | serious PRR 3.9 | no trial data cached |
| Product prescribing issue | 14 | 6.3 3.7–10.6ROR 6.3 · χ² 57 / p 2e-14 | 5.3 EB05 3.4 · IC025 +1.5 3/3 methods agree | Reporting / coding artifact | serious PRR 3.7 | no trial data cached |
| Inflammation | 35 | 6.2 4.5–8.7ROR 6.3 · χ² 149 / p 1e-34 | 5.8 EB05 4.3 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 | no trial data cached |
| Oral pain | 15 | 6.1 3.7–10.1ROR 6.1 · χ² 59 / p 7e-15 | 5.2 EB05 3.4 · IC025 +1.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.7 | no trial data cached |
| Blister | 36 | 5.9 4.3–8.1ROR 6.0 · χ² 141 / p 7e-33 | 5.5 EB05 4.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 5.4 | no trial data cached |
| Lymphadenopathy | 22 | 5.7 3.7–8.6ROR 5.7 · χ² 80 / p 2e-19 | 5.1 EB05 3.6 · IC025 +1.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.0 | no trial data cached |
| Scar | 10 | 5.3 2.9–9.9ROR 5.4 · χ² 31 / p 1e-8 | 4.4 EB05 2.6 · IC025 +1.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.0 | no trial data cached |
| Skin disorder | 19 | 5.2 3.3–8.2ROR 5.3 · χ² 61 / p 3e-15 | 4.7 EB05 3.2 · IC025 +1.5 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 5.0 | no trial data cached |
| Chills | 63 | 4.9 3.8–6.3ROR 5.0 · χ² 193 / p 3e-44 | 4.7 EB05 3.8 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 5.6 · ♀ 29% (drug 50%) | no trial data cached |
| Mouth ulceration | 11 | 4.8 2.7–8.6ROR 4.8 · χ² 29 / p 3e-8 | 4.1 EB05 2.4 · IC025 +1.0 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.4 | no trial data cached |
| Oral herpes | 10 | 4.7 2.5–8.7ROR 4.7 · χ² 26 / p 2e-7 | 3.9 EB05 2.3 · IC025 +0.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.3 | no trial data cached |
| Eye irritation | 27 | 4.4 3.0–6.4ROR 4.5 · χ² 69 / p 6e-17 | 4.1 EB05 3.0 · IC025 +1.4 3/3 methods agree | Labeled (related wording) related wording | serious PRR 9.4 | no trial data cached |
| Skin exfoliation | 39 | 4.3 3.1–5.9ROR 4.4 · χ² 96 / p 7e-23 | 4.1 EB05 3.1 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 5.5 | 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 |
|---|---|---|---|---|---|---|
| Erythema (skin redness) | 183 | 8.2 7.1–9.4ROR 8.8 · χ² 1,153 / p 5e-253 | 8.0 EB05 7.1 · IC025 +2.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.8 | no trial data cached |
| Product use in unapproved indication | 174 | 6.5 5.7–7.5ROR 7.0 · χ² 817 / p 6e-180 | 6.4 EB05 5.7 · IC025 +2.4 3/3 methods agree | Reporting / coding artifact | serious PRR 3.9 | no trial data cached |
| Influenza like illness (flu-like illness) | 102 | 11.3 9.4–13.7ROR 11.8 · χ² 950 / p 6e-209 | 11.1 EB05 9.4 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 12.6 | no trial data cached |
| Application site erythema | 100 | 34.9 28.8–42.3ROR 36.4 · χ² 3,250 / p <1e-300 | 34.6 EB05 29.2 · IC025 +4.6 3/3 methods agree | Labeled (related wording) related wording | serious n=30 | no trial data cached |
| Scab | 76 | 61.7 49.5–77.1ROR 63.8 · χ² 4,453 / p <1e-300 | 60.4 EB05 49.9 · IC025 +5.1 3/3 methods agree | Labeled adverse reaction exact term | serious n=38 | no trial data cached |
| Application site pain | 73 | 30.4 24.3–38.2ROR 31.4 · χ² 2,044 / p <1e-300 | 30.1 EB05 24.8 · IC025 +4.3 3/3 methods agree | Labeled (related wording) related wording | serious n=15 · 86% consumer | no trial data cached |
| Chills | 63 | 4.9 3.8–6.3ROR 5.0 · χ² 193 / p 3e-44 | 4.7 EB05 3.8 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 5.6 · ♀ 29% (drug 50%) | no trial data cached |
| Drug ineffective for unapproved indication | 55 | 9.0 7.0–11.7ROR 9.2 · χ² 386 / p 4e-86 | 8.6 EB05 6.8 · IC025 +2.6 3/3 methods agree | Reporting / coding artifact | serious PRR 11.1 | no trial data cached |
| Skin ulcer | 49 | 17.4 13.2–23.0ROR 17.8 · χ² 740 / p 3e-163 | 17.2 EB05 13.5 · IC025 +3.4 3/3 methods agree | Labeled (related wording) related wording | serious PRR 11.8 · ♀ 73% (drug 50%) | no trial data cached |
| Skin irritation | 47 | 9.4 7.1–12.4ROR 9.6 · χ² 344 / p 5e-77 | 8.9 EB05 6.9 · IC025 +2.6 3/3 methods agree | Labeled (related wording) related wording | serious n=6 · ♀ 78% (drug 50%) · 94% clinician | no trial data cached |
| Oedema | 42 | 7.1 5.3–9.6ROR 7.2 · χ² 215 / p 7e-49 | 6.7 EB05 5.1 · IC025 +2.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 1.8 · 93% clinician | no trial data cached |
| Skin exfoliation | 39 | 4.3 3.1–5.9ROR 4.4 · χ² 96 / p 7e-23 | 4.1 EB05 3.1 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 5.5 | no trial data cached |
| Skin reaction | 38 | 24.8 18.1–34.0ROR 25.2 · χ² 841 / p 3e-185 | 24.4 EB05 18.6 · IC025 +3.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 39.3 | no trial data cached |
| Blister | 36 | 5.9 4.3–8.1ROR 6.0 · χ² 141 / p 7e-33 | 5.5 EB05 4.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 5.4 | no trial data cached |
| Inflammation | 35 | 6.2 4.5–8.7ROR 6.3 · χ² 149 / p 1e-34 | 5.8 EB05 4.3 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 | 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.
- Influenza like illness — n=102, PRR 11.3
- Anhedonia — n=25, PRR 8.6
- Inflammation — n=35, PRR 6.2
- Blister — n=36, PRR 5.9
- Chills — n=63, PRR 4.9
- Skin exfoliation — n=39, PRR 4.3
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 Imiquimod?
In FDA FAERS, the most frequently co-reported reaction terms for Imiquimod are erythema, influenza like illness, application site erythema, scab, application site pain, chills. 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 Imiquimod have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: Important: For use on the skin only (topical). Do not use Imiquimod Cream in or near your mouth, eyes, nose or vagina.
Do FAERS signals prove that Imiquimod 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 59af8153-4cf8-4f22-9000-f239798d52d1, effective 20250811; matched on
openfda.generic_name.exact:"IMIQUIMOD") - 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, 86 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.