Malathion
| Evidence Level: L5 | Predicted Indications: 10 |
Table of Contents
Malathion: From Head Lice Infestation to Seborrheic Keratosis
One-Sentence Summary
Malathion is a topical organophosphate originally used to treat head lice (Pediculus humanus capitis) infestation. The TxGNN model predicts it may be effective for seborrheic keratosis, but no clinical trials and no publications currently support this direction, so it is a model prediction only.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Head lice infestation (Pediculus humanus capitis) |
| Predicted New Indication | Seborrheic keratosis |
| TxGNN Prediction Score | 96.45% |
| Evidence Level | L5 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 1 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available. Based on known information, malathion is an organophosphate that inhibits acetylcholinesterase and is applied to the skin as a pediculicide. Its efficacy in head lice is established, but the data compiled for this report do not show a mechanistic route to seborrheic keratosis, which is a benign overgrowth of skin cells.
The high score most likely reflects similarity patterns in the knowledge graph (for example, shared links with other skin conditions) rather than a demonstrated pharmacological effect. The link is therefore speculative and should be treated as a hypothesis only.
Other predictions for this drug follow the same pattern. All ten top predictions have no trials or literature and are rated L5 with a Hold recommendation. They include vulvar inverted follicular keratosis (96.05%), seborrheic dermatitis (94.12%), mycotic corneal ulcer (82.95%), inherited skin tumour (77.01%), anogenital HPV infection (76.56%), and several benign breast conditions (74.0–76.1%).
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
Currently no related literature available.
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN09320P | LICE CARE LOTION 0.5% w/v (ICM Pharma Pte. Ltd.) | Emulsion | Not stated in the available data |
Safety Considerations
- Disease-level contraindication (knowledge graph): dermatitis. This comes from the model's knowledge graph, not from the package insert.
- Drug Interactions: No interactions were found in the queried data.
Please refer to the package insert for full warnings and contraindications.
Additional cautions noted in the prediction analysis:
- Organophosphates carry irritant and neurotoxic concerns, which matter for chronic conditions such as seborrheic dermatitis.
- Ocular use (mycotic corneal ulcer) raises significant safety concerns.
- Malathion has been classified as IARC Group 2A (probably carcinogenic to humans), which argues for caution in any tumour-related use.
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction rests on a model score alone, with no clinical trials, no publications, and no established mechanism. The safety profile of an organophosphate (skin irritation, neurotoxicity, and carcinogenicity classification) also makes a repurposing case for a benign condition hard to justify at this point.
To proceed, the following is needed:
- Package insert warnings and contraindications from the Singapore regulator (HSA), which are currently missing and block safety screening
- Mechanism of action data (for example, from DrugBank) to test whether any plausible link to seborrheic keratosis exists
- A literature search for any preclinical or clinical evidence in keratinocytic lesions
- Route and formulation compatibility assessment for the new indication
- A risk-benefit review comparing malathion with existing treatments for seborrheic keratosis
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.