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 topical pyrethroid antiparasitic agent whose established indication is scabies (mite infestation of the skin). The TxGNN model predicts it may also be effective for Trombiculiasis (chigger mite dermatitis), a prediction currently supported by 0 clinical trials and 1 publication (a veterinary case series).
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Scabies (topical antiparasitic use — inferred from mechanistic rationale; no TFDA licence record available) |
| Predicted New Indication | Trombiculiasis |
| TxGNN Prediction Score | 95.16% |
| Evidence Level | L4 |
| Australia Market Status | Not marketed |
| Number of ARTG Entries | 0 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available for permethrin in this evidence pack. Based on the information provided, permethrin is a pyrethroid insecticide/acaricide that acts on voltage-gated sodium channels in arthropods, causing paralysis and death. This mechanism underlies its established use against scabies (Sarcoptes scabiei mite infestation).
Trombiculiasis is a dermatitis caused by the larvae of chigger mites (Neotrombicula/Trombicula species), a different but biologically related arthropod. Since both conditions involve mite infestation of the skin and permethrin’s mode of action targets arthropod nervous systems broadly, mechanistic extrapolation from scabies to trombiculiasis has biological plausibility.
However, the only supporting evidence identified is a veterinary case series in dogs treated for Neotrombicula autumnalis dermatitis using a permethrin-pyriproxyfen combination — not a human study. This limits confidence in direct translation to human trombiculiasis management.
Clinical Trial Evidence
Currently no related clinical trials registered
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 14984153 | 2004 | Cohort (veterinary) | The Journal of small animal practice | In 15 dogs with Neotrombicula autumnalis-induced pruritic dermatitis, a topical permethrin-pyriproxyfen combination resolved infestation and dermatitis in 14/15 dogs within one to three weeks |
Note: this is a veterinary (canine) study, not a human clinical study — relevant when weighing applicability to human trombiculiasis.
Safety Considerations
Please refer to the TGA-approved Product Information (PI) for safety information.
Conclusion and Next Steps
Decision: Hold
Rationale: The only supporting evidence is a single veterinary case series in dogs, with no human clinical trials, no ANZCTR/ICTRP registrations, and no TFDA/TGA safety documentation available. A blocking data gap (missing TFDA/PI warnings and contraindications) currently prevents a formal safety assessment (S1 stage).
To proceed, the following is needed:
- TGA-approved Product Information (warnings, contraindications, drug interactions)
- Human clinical evidence (case series, observational study, or trial) for permethrin in trombiculiasis
- Confirmation of available and required routes/formulations for this indication
- Drug-drug interaction data (currently not found)
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.