Acetic Acid

Evidence Level: L5

Predicted Indications: 10

Acetic Acid
Acetic Acid: From Otitis Externa to Post-Bacterial Disorder

## Pharmacist Assessment Report

Acetic Acid: From Otitis Externa to Post-Bacterial Disorder

One-Sentence Summary

Acetic acid was originally used as a topical antibacterial and acidifying agent for otitis externa and external ear disease. The TxGNN model predicts it may be effective for post-bacterial disorder, but no clinical trials and no directly relevant publications currently support this prediction.

Quick Overview

Item	Content
Original Indication	Otitis externa; external ear disease (from the knowledge graph; the Singapore licences list no indication text)
Predicted New Indication	Post-bacterial disorder
TxGNN Prediction Score	99.98%
Evidence Level	L5
Singapore Market Status	✓ Marketed
Number of Registrations	2
Recommended Decision	Hold

Why is This Prediction Reasonable?

Detailed mechanism of action data is not available. Acetic acid is generally known as a topical antibacterial and acidifying agent. Its efficacy in otitis externa rests on lowering local pH and inhibiting microbial growth.

"Post-bacterial disorder" is a vague category. It covers conditions that arise after an infection, and these are often immune-mediated or involve tissue damage rather than active infection. A topical agent that acts locally on microbes has no clear mechanism for such conditions. The high score most likely reflects the disease's proximity to infection-related conditions in the knowledge graph rather than a true pharmacological link.

The other top-ranked predictions have the same weakness. They include postinfectious vasculitis, post-infectious syndrome, Chagas cardiomyopathy, infective urethral stricture and infection-related haemolytic uraemic syndrome. All are L5, and none has supporting trials or literature.

The only prediction with some supporting literature is tinea corporis (rank 9, score 99.25%, L4). It is described below as a possible research question.

Clinical Trial Evidence

Currently no related clinical trials registered for post-bacterial disorder. No trials were found for any of the other predicted indications either.

Literature Evidence

Currently no related literature available for post-bacterial disorder.

For reference, the only literature retrieved for the top predictions is a 2011 review of animal models of post-infectious irritable bowel syndrome (PMID 20848144, listed under post-infectious syndrome). It does not study acetic acid, so it is not evidence for this drug.

PMID	Year	Type	Journal	Key Findings
20996178	1946	Historical clinical report	JAMA	Tinea capitis treated with iodine and dilute acetic acid
20983383	1946	Historical clinical report	Arch Dermatol Syphilol	Same treatment approach for tinea capitis
20256868	1947	Historical case series	Urol Cutaneous Rev	Results in a larger series of tinea capitis patients
13616002	1958	Historical clinical report	Vestn Dermatol Venerol	Foot epidermophytosis treated with increasing acetic acid concentrations
31049344	2019	Case series	Skin Appendage Disord	Chemical peeling as an alternative to oral antifungals for onychomycosis (indirect)
26857689	2016	In vitro	Mycoses	Topical antifungal products tested in an onychomycosis model (indirect)
16233325	2002	In vitro	J Biosci Bioeng	Organic acids at low pH inhibited the tinea dermatophyte (indirect)
37256034	2023	Case series	Arch Plast Surg	Burns caused by Korean folk remedies (a skin-injury safety signal)

These studies are old and uncontrolled, or only indirectly related. No modern controlled study in tinea corporis was identified.

Singapore Market Information

Authorization Number	Product Name	Dosage Form	Approved Indication
SIN11034P	Haemodialysis Concentrate NKFS-04 (Acid) for Bicarbonate Dialysis	Solution	Not stated
SIN11033P	Haemodialysis Concentrate NKFS-03 (Acid) for Bicarbonate Dialysis	Solution	Not stated

Both registered products are haemodialysis concentrates, not otic or topical products. The local registrations therefore do not cover the original ear indication or any of the predicted new indications.

Safety Considerations

Contraindications (knowledge graph, not label text): inherited porphyria, porphyrin metabolism disease, porphyria, herpes simplex infection, and geniculate herpes zoster.
Skin injury: a case series reported burns from folk remedies, which signals a risk of skin damage with improper use. Acetic acid is also an irritant and is unsuitable for periocular or ocular use at antimicrobial concentrations.
Drug Interactions: no interactions were found in the queried data.

Please refer to the package insert for the full warnings and contraindications.

Conclusion and Next Steps

Decision: Hold

Rationale: The prediction rests on model score alone (L5). There are no clinical trials or relevant literature, and the mechanism is implausible for a post-infectious sequela. The registered Singapore products are dialysis concentrates, so there is no matching local product.

To proceed, the following is needed:

Package insert warnings and contraindications from HSA, which block safety screening
Mechanism of action data from DrugBank
A clearer, more specific definition of the target disease. If the project continues, tinea corporis (rank 9, L4) is the more credible research question, and it would need modern controlled evidence.
Confirmation of a suitable topical product and route, since route compatibility has not been assessed
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.