Tolnaftate side effects: what 1,292 FDA adverse event reports show

Tolnaftate · Mycozyl Al · 38 reaction terms · 301 drug–reaction co-reports · data 2026-09-14

Drug class

Antifungal

FDA label, Indications wording

Brand names

Mycozyl Al

openFDA label

Who reports

1,292 reports · 61% serious · 90 with death outcome · 55% female

openFDA FAERS counts, all years, deduplication not applied

Used for

Mycozyl AL™ is effective in the treatment of most skin infections such as athlete's foot (tinea pedis) and ringworm (tinea corporis). Mycozyl AL™ has been designed to reach skin areas around and under the nails while it relives burning, cracking, scaling and discomfort which accompany these conditions.

FDA label, Indications and Usage

What it is

DESCRIPTION: Each gram of Mycozyl AL™ contains 10 mg of tolnaftate in a vehicle consisting of: Apple Cider Vinegar, Argania Spinosa (Argan) Kernel Oil, Benzyl Alcohol, DMSO (Dimethyl Sulfoxide.

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 23 strongest signals

Reporting / coding artifact 5Lab value / disease marker 3No label text to screen 15

What the badges mean

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.
No label text to screen No validated FDA label was retrievable for this product, so the screen could not run. Disproportionality only.

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. 15 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
Drug administered at inappropriate site	13	19.7 11.5–33.9ROR 19.9 · χ² 213 / p 2e-48	18.9 EB05 11.3 · IC025 +2.6 3/3 methods agree	No label text to screen label has no adverse-reaction text	–	no trial data cached
Blood potassium increased	14	14.0 8.3–23.6ROR 14.1 · χ² 156 / p 4e-36	12.9 EB05 7.4 · IC025 +2.4 3/3 methods agree	Lab value / disease marker	serious PRR 17.3	no trial data cached
Deformity	7	12.1 5.8–25.4ROR 12.2 · χ² 61 / p 3e-15	9.1 EB05 4.0 · IC025 +1.5 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 13.2	no trial data cached
Red blood cell sedimentation rate increased	8	11.7 5.9–23.4ROR 11.8 · χ² 68 / p 8e-17	9.1 EB05 4.3 · IC025 +1.6 3/3 methods agree	Lab value / disease marker	serious PRR 12.6	no trial data cached
Abasia	18	11.7 7.4–18.4ROR 11.8 · χ² 165 / p 5e-38	10.6 EB05 6.6 · IC025 +2.4 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 12.5	no trial data cached
Hepatic cirrhosis	13	11.3 6.6–19.4ROR 11.4 · χ² 112 / p 2e-26	9.7 EB05 5.5 · IC025 +2.1 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 10.8	no trial data cached
Anhedonia	16	9.8 6.0–16.0ROR 9.9 · χ² 118 / p 9e-28	8.5 EB05 5.2 · IC025 +2.1 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 10.3	no trial data cached
Application site pain	13	9.6 5.6–16.5ROR 9.7 · χ² 92 / p 5e-22	8.0 EB05 4.7 · IC025 +1.9 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious n=3	no trial data cached
Skin lesion	15	8.9 5.4–14.8ROR 9.0 · χ² 98 / p 2e-23	7.6 EB05 4.7 · IC025 +2.0 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 11.9	no trial data cached
Economic problem	8	8.4 4.2–16.8ROR 8.5 · χ² 45 / p 9e-12	6.2 EB05 3.2 · IC025 +1.3 3/3 methods agree	Reporting / coding artifact	serious PRR 8.7	no trial data cached
Body height decreased	5	7.5 3.1–18.0ROR 7.5 · χ² 22 / p 1e-6	4.9 EB05 2.2 · IC025 +0.7 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious n=3	no trial data cached
Hip arthroplasty	7	7.5 3.6–15.7ROR 7.5 · χ² 33 / p 4e-9	5.4 EB05 2.7 · IC025 +1.1 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 7.3	no trial data cached
Tooth disorder	10	7.3 3.9–13.5ROR 7.3 · χ² 48 / p 2e-12	5.7 EB05 3.3 · IC025 +1.4 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 11.9	no trial data cached
Impaired driving ability	5	7.1 3.0–17.1ROR 7.1 · χ² 21 / p 3e-6	4.7 EB05 2.2 · IC025 +0.6 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 7.2	no trial data cached
Application site erythema	11	6.8 3.8–12.2ROR 6.8 · χ² 49 / p 2e-12	5.5 EB05 3.2 · IC025 +1.4 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious n=2	no trial data cached
Glycosylated haemoglobin increased	10	6.4 3.5–11.9ROR 6.5 · χ² 41 / p 9e-11	5.1 EB05 3.0 · IC025 +1.3 3/3 methods agree	Lab value / disease marker	serious PRR 12.5	no trial data cached
Expired product administered	12	5.9 3.3–10.3ROR 5.9 · χ² 44 / p 2e-11	4.9 EB05 3.0 · IC025 +1.3 3/3 methods agree	Reporting / coding artifact	serious n=2	no trial data cached
Disability	7	5.7 2.7–12.0ROR 5.8 · χ² 23 / p 9e-7	4.3 EB05 2.3 · IC025 +0.8 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 5.6	no trial data cached
Incorrect drug administration duration	10	5.7 3.1–10.5ROR 5.7 · χ² 34 / p 3e-9	4.6 EB05 2.7 · IC025 +1.1 3/3 methods agree	Reporting / coding artifact	–	no trial data cached
Drug prescribing error	6	5.0 2.2–11.1ROR 5.0 · χ² 15 / p 4e-5	3.8 EB05 1.9 · IC025 +0.5	Reporting / coding artifact	serious n=1	no trial data cached
Skin irritation	14	4.9 2.9–8.3ROR 5.0 · χ² 40 / p 1e-10	4.3 EB05 2.7 · IC025 +1.2 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious n=10	no trial data cached
Psoriatic arthropathy	9	3.6 1.9–7.0ROR 3.6 · χ² 15 / p 7e-5	3.2 EB05 1.8 · IC025 +0.5	No label text to screen label has no adverse-reaction text	serious PRR 4.3	no trial data cached
Drug effect decreased	11	3.3 1.8–5.9ROR 3.3 · χ² 15 / p 5e-5	3.0 EB05 1.8 · IC025 +0.5	Reporting / coding artifact	serious PRR 1.0	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
Abasia	18	11.7 7.4–18.4ROR 11.8 · χ² 165 / p 5e-38	10.6 EB05 6.6 · IC025 +2.4 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 12.5	no trial data cached
Anhedonia	16	9.8 6.0–16.0ROR 9.9 · χ² 118 / p 9e-28	8.5 EB05 5.2 · IC025 +2.1 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 10.3	no trial data cached
Skin lesion	15	8.9 5.4–14.8ROR 9.0 · χ² 98 / p 2e-23	7.6 EB05 4.7 · IC025 +2.0 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 11.9	no trial data cached
Skin irritation	14	4.9 2.9–8.3ROR 5.0 · χ² 40 / p 1e-10	4.3 EB05 2.7 · IC025 +1.2 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious n=10	no trial data cached
Blood potassium increased	14	14.0 8.3–23.6ROR 14.1 · χ² 156 / p 4e-36	12.9 EB05 7.4 · IC025 +2.4 3/3 methods agree	Lab value / disease marker	serious PRR 17.3	no trial data cached
Application site pain	13	9.6 5.6–16.5ROR 9.7 · χ² 92 / p 5e-22	8.0 EB05 4.7 · IC025 +1.9 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious n=3	no trial data cached
Hepatic cirrhosis	13	11.3 6.6–19.4ROR 11.4 · χ² 112 / p 2e-26	9.7 EB05 5.5 · IC025 +2.1 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 10.8	no trial data cached
Drug administered at inappropriate site	13	19.7 11.5–33.9ROR 19.9 · χ² 213 / p 2e-48	18.9 EB05 11.3 · IC025 +2.6 3/3 methods agree	No label text to screen label has no adverse-reaction text	–	no trial data cached
Accidental exposure to product	12	1.9 1.1–3.4ROR 2.0 · χ² 5 / p 0.016	1.9 EB05 1.2 · IC025 -0.1 PRR-only: not supported by EBGM or IC	Reporting / coding artifact	serious PRR 6.9	no trial data cached
Expired product administered	12	5.9 3.3–10.3ROR 5.9 · χ² 44 / p 2e-11	4.9 EB05 3.0 · IC025 +1.3 3/3 methods agree	Reporting / coding artifact	serious n=2	no trial data cached
Drug effect decreased	11	3.3 1.8–5.9ROR 3.3 · χ² 15 / p 5e-5	3.0 EB05 1.8 · IC025 +0.5	Reporting / coding artifact	serious PRR 1.0	no trial data cached
Application site erythema	11	6.8 3.8–12.2ROR 6.8 · χ² 49 / p 2e-12	5.5 EB05 3.2 · IC025 +1.4 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious n=2	no trial data cached
Incorrect drug administration duration	10	5.7 3.1–10.5ROR 5.7 · χ² 34 / p 3e-9	4.6 EB05 2.7 · IC025 +1.1 3/3 methods agree	Reporting / coding artifact	–	no trial data cached
Glycosylated haemoglobin increased	10	6.4 3.5–11.9ROR 6.5 · χ² 41 / p 9e-11	5.1 EB05 3.0 · IC025 +1.3 3/3 methods agree	Lab value / disease marker	serious PRR 12.5	no trial data cached
Tooth disorder	10	7.3 3.9–13.5ROR 7.3 · χ² 48 / p 2e-12	5.7 EB05 3.3 · IC025 +1.4 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 11.9	no trial data cached

Unlabeled candidate signals

Every screened signal with n ≥ 20 was either labeled, an indication term, or an artifact pattern — no unlabeled candidate stood out in the top signals.

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 Tolnaftate?

In FDA FAERS, the most frequently co-reported reaction terms for Tolnaftate are abasia, anhedonia, skin lesion, skin irritation, blood potassium increased, application site pain. 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 Tolnaftate have an FDA boxed warning?

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

Do FAERS signals prove that Tolnaftate 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 07edd043-4ac4-b2de-e063-6394a90af25d, effective 20231017; matched on openfda.generic_name.exact:"TOLNAFTATE" AND openfda.product_type:"HUMAN PRESCRIPTION DRUG")
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.