Benserazide
| Evidence Level: L5 | Predicted Indications: 10 |
Table of Contents
Benserazide: From Parkinsonism to Congenital Hypotrichosis Milia
One-Sentence Summary
Benserazide is a peripheral aromatic L-amino acid decarboxylase (AADC) inhibitor, marketed in Singapore as part of the Madopar combination with levodopa, which is used for Parkinsonism and restless legs syndrome. The TxGNN model predicts it may be effective for congenital hypotrichosis milia, but there are 0 clinical trials and 0 publications supporting this direction. The prediction rests on knowledge-graph similarity alone.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Parkinsonism and restless legs syndrome (from pharmacology reference data; the Singapore licence records carry no indication text) |
| Predicted New Indication | Congenital hypotrichosis milia |
| TxGNN Prediction Score | 98.44% |
| Evidence Level | L5 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 4 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available in the compiled records. Based on known information, benserazide inhibits peripheral AADC (the DDC enzyme). It is paired with levodopa so that more levodopa reaches the brain. The pharmacology data also list cystathionine β-synthase (CBS) as a target.
No mechanistic link has been identified between AADC inhibition and congenital hypotrichosis milia, a rare hereditary hair disorder. The high score (0.984) reflects a graph-based prediction only, so the prediction is not supported by mechanism or by clinical evidence.
Other hair-related predictions show the same pattern:
- Hypotrichosis simplex of the scalp (98.39%): no trials or literature.
- Diffuse alopecia areata (98.12%): this is an autoimmune condition (JAK/STAT, T-cell mediated), unrelated to AADC inhibition.
- Alopecia (97.76%): the single linked paper (PMID 34900390) is a commentary on alopecia areata as an adverse effect of tremor drugs. It is not evidence of benefit.
Among the other top-ranked predictions, headache disorder carries a safety signal. A 1979 clinical observation reported that benserazide induced migraine attacks.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
Currently no related literature available for congenital hypotrichosis milia.
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN06121P | MADOPAR 125 CAPSULE 125 mg | Capsule | Not stated in the licence record |
| SIN05195P | MADOPAR HBS 125 CAPSULE | Capsule | Not stated in the licence record |
| SIN11075P | MADOPAR DISPERSIBLE TABLETS 125 mg | Tablet | Not stated in the licence record |
| SIN06119P | MADOPAR 250 TABLET 250 mg | Tablet | Not stated in the licence record |
All four licences are valid, held for single-ingredient registrations, and manufactured by Delpharm Milano S.r.l. The available dosage forms are oral capsules and tablets.
Safety Considerations
- Drug Interactions / Pharmacological Targets: Benserazide acts on L-aromatic amino-acid decarboxylase (DDC) and also on cystathionine β-synthase (CBS). No drug-drug interaction severity levels are available.
- Migraine signal: A 1979 observational report (PMID 554794) found typical migraine attacks in the 4 migrainous women given benserazide 125 mg. This was preliminary and in a very small group, but it argues against use in headache disorders.
- Catecholamine effects: Because AADC inhibition may alter catecholamine output, use in catecholamine-secreting tumours such as phaeochromocytoma needs caution.
Please refer to the package insert for further safety information, including warnings and contraindications.
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction for congenital hypotrichosis milia comes from the TxGNN model only (Evidence Level L5). There are no trials or publications, and no plausible mechanistic link to AADC inhibition. The other top-ranked predictions are also unsupported, and some, such as headache disorder, show a safety signal in the opposite direction.
To proceed, the following is needed:
- Package insert warnings and contraindications from the HSA website (a blocking gap for safety screening)
- Mechanism of action data for benserazide
- A biologically plausible hypothesis linking AADC (or CBS) inhibition to hair follicle development, with preclinical support
- Approved indication text for the Singapore licences
- Assessment of route compatibility (oral forms only are currently registered; a topical or other route may be needed for a hair disorder)
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.