Formaldehyde
| Evidence Level: L5 | Predicted Indications: 10 |
Table of Contents
Formaldehyde: From Influenza to Leishmaniasis, Diffuse Cutaneous
One-Sentence Summary
Formaldehyde has an original association to influenza, most likely reflecting its historical use to inactivate viruses in vaccine manufacturing. The TxGNN model (deep learning) predicts it may be relevant to diffuse cutaneous leishmaniasis (score 0.9993). This score comes from the TxGNN model and may reflect similarities the model learned between related diseases, not biological evidence. No clinical trials and no supporting publications were found for this prediction. This is a model-only signal, and the drug’s toxicity profile argues strongly against therapeutic repurposing.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Influenza (from the knowledge graph; no approved indication text is recorded for the Australian entry) |
| Predicted New Indication | Leishmaniasis, diffuse cutaneous |
| TxGNN Prediction Score | 0.9993 |
| Evidence Level | L5 |
| Australia Market Status | Listed on the PBS Schedule (1 of 1 items) – TGA (ARTG) registration status is not included in this data |
| Number of PBS Items | 1 (valid: 1) |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism of action data is not available for this drug. Formaldehyde is known as a non-selective cross-linking agent and tissue fixative. It reacts with proteins and nucleic acids, which is why it is used to inactivate viruses and toxins in vaccine production and to preserve tissue.
The link between influenza and diffuse cutaneous leishmaniasis is weak. The first is a viral respiratory infection, and the second is a parasitic skin disease caused by an intracellular protozoan. The high score comes from the TxGNN model (deep learning) and may reflect similarities the model learned between related diseases, not biological evidence. It does not reflect a demonstrated therapeutic mechanism.
Formaldehyde’s cross-linking activity is not selective. It cannot be used safely in the body to target intracellular Leishmania parasites. It is also classified as a human carcinogen (IARC Group 1), so there is no plausible route to systemic therapeutic use for this disease.
Other predictions in the data compiled for this report show the same pattern. Mucocutaneous leishmaniasis, mitochondrial cytochrome c oxidase deficiency and hemophagocytic syndromes have no supporting evidence. The literature retrieved for pyelonephritis, streptococcal pneumonia, trigonitis, malaria and X-linked lymphoproliferative syndrome describes formaldehyde as a laboratory fixative, a vaccine manufacturing reagent or an occupational hazard. None of it evaluates formaldehyde as a treatment.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
Currently no related literature available for diffuse cutaneous leishmaniasis.
Literature was retrieved for other lower-ranked predicted indications, but none of it evaluates formaldehyde as a treatment:
- Pyelonephritis: Four papers cover nephrocalcinosis, a hamster lymphoma agent, a soil microbe as a uropathogen and an animal vaccine study. A loose indirect link exists through methenamine, which releases formaldehyde in acidic urine.
- X-linked lymphoproliferative syndrome: The papers are mainly occupational epidemiology (for example, PMID 31870335, a 2019 meta-analysis, and PMID 41146278, a 2025 case-control study) linking formaldehyde exposure to lymphoid malignancy risk. This points toward harm, not benefit.
- Plasmodium falciparum malaria, streptococcal pneumonia and trigonitis: The papers use formaldehyde as a fixative or vaccine reagent, or are anatomical and laboratory method studies.
Australia Market Information
| ARTG Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| ARTG 479F | Not recorded | Not recorded | Not recorded |
The Australian entry in the data compiled for this report has no recorded product name, dosage form or approved indication text. These details should be verified against the TGA register.
Safety Considerations
Please refer to the TGA-approved Product Information (PI) for safety information.
The literature compiled for this report consistently identifies formaldehyde as a human carcinogen (IARC Group 1). Occupational exposure has been associated with nasopharyngeal cancer and leukaemia, and possibly with lymphoma subtypes. No drug interactions were found in the data compiled for this report.
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction rests on a TxGNN model (deep learning) score alone, which may reflect similarities the model learned between related diseases, not biological evidence. There are no clinical trials and no relevant publications. Formaldehyde is a non-selective, carcinogenic cross-linking agent, so there is no plausible route to safe therapeutic use for diffuse cutaneous leishmaniasis or the other predicted conditions.
To proceed, the following is needed:
- Detailed mechanism of action data
- TGA Product Information with warnings and contraindications (safety screening cannot proceed without it)
- Confirmation of the product type, dosage form and approved use for the Australian entry
- Any preclinical evidence of antileishmanial activity at a safely achievable exposure
- Route compatibility and similarity analyses, which are currently pending
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.