Permethrin
| 證據等級: L5 | 預測適應症: 10 個 |
目錄
Permethrin: From Scabies to Trombiculiasis
One-Sentence Summary
Permethrin is a pyrethroid antiparasitic agent whose established pharmacology targets sodium-channel function in arthropod nervous systems (used clinically against mite infestations such as scabies, Sarcoptes scabiei). The TxGNN model predicts it may also be effective for Trombiculiasis (chigger/harvest-mite dermatitis), a mechanistically related mite infestation, but this direction is currently supported by only 1 veterinary case-series publication and no clinical trials or human data.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Scabies (mite infestation) — noted in the mechanistic rationale; not confirmed via structured regulatory fields, as original_indications and original_moa are not populated in this Evidence Pack |
| Predicted New Indication | Trombiculiasis |
| TxGNN Prediction Score | 95.16% |
| Evidence Level | L4 (preclinical/mechanistic — single animal case study only) |
| Denmark Market Status | Not marketed |
| Number of Marketing Authorisations | 0 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism-of-action data for Permethrin is not available in this Evidence Pack (original_moa is flagged as a data gap). Based on known pharmacology referenced in the model’s rationale, Permethrin is a pyrethroid that disrupts sodium-channel function in the nervous system of mites and other arthropods, and its efficacy against scabies (caused by the mite Sarcoptes scabiei) is well established in clinical practice.
Trombiculiasis is dermatitis caused by chigger mite larvae (e.g. Neotrombicula autumnalis), which — like scabies mites — belong to the Acari (mite) family. Because Permethrin’s killing mechanism acts on mite neuromuscular sodium channels broadly rather than on a species-specific target, the same mechanism is plausible against chigger mites, giving this prediction reasonable mechanistic grounding.
However, the only supporting evidence currently available is a 2004 veterinary case series in dogs, not human clinical data. The mechanistic plausibility is credible, but translation to a validated human indication has not been demonstrated.
Note on other TxGNN predictions in this evidence pack: lower-ranked candidates (lip neoplasm, lower lip fistula, anisakiasis, toxascariasis) were also generated by the model but are assessed in the rationale data as likely knowledge-graph noise — they have no plausible mechanistic link to Permethrin’s arthropod-specific sodium-channel activity, and no supporting literature or trials exist for any of them. This report therefore focuses on the strongest candidate, Trombiculiasis.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 14984153 | 2004 | Animal Case Study (Veterinary) | The Journal of Small Animal Practice | Topical permethrin-pyriproxyfen combinations resolved Neotrombicula autumnalis mite dermatitis in 14 of 15 naturally infested dogs within 1–3 weeks; no human clinical data |
Caveat: This is the sole piece of supporting evidence, is veterinary (canine) rather than human, and used a permethrin-pyriproxyfen combination product rather than Permethrin alone.
Denmark Market Information
Permethrin currently holds no marketing authorisations in Denmark (market status: Not marketed). No product, dosage-form, or approved-indication data is available from Danish regulatory records for this substance.
Safety Considerations
Please refer to the approved Summary of Product Characteristics (SmPC) for safety information. No key warnings, contraindications, or drug-drug interaction data were returned for Permethrin in this Evidence Pack.
Conclusion and Next Steps
Decision: Hold
Rationale:
- Evidence is limited to a single veterinary case series (L4, mechanistic/preclinical level) with no human clinical trials, and Permethrin has no existing marketing authorisation in Denmark to serve as a regulatory foothold for a new indication.
To proceed, the following is needed:
- Confirmed mechanism-of-action documentation (currently a data gap)
- Human clinical data (case reports, observational studies, or trials) evaluating Permethrin specifically for trombiculiasis/chigger mite dermatitis
- Safety and warning/contraindication data (currently a blocking data gap — no SmPC-level information available)
- Drug-drug interaction data (current query returned no results)
- Assessment of regulatory pathway, since the substance is not currently marketed in Denmark
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.