Cyclizine
| Evidence Level: L4 | Predicted Indications: 10 |
Table of Contents
Cyclizine: From Antiemetic/Antihistamine Use to Allergic Urticaria
One-Sentence Summary
Cyclizine is a first-generation piperazine-class H1-antihistamine, classically associated with antiemetic and anti-vertigo use (its formal original-indication record is not available in this evidence pack). The TxGNN model predicts it may be effective for Allergic Urticaria, but this direction is currently supported by only 0 clinical trials and 1 publication, and that single publication does not directly study cyclizine.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not on file — no UK marketing authorisation licences recorded for this drug; classically developed as an H1-antihistamine antiemetic (nausea, vomiting, vertigo/motion sickness) |
| Predicted New Indication | Allergic Urticaria |
| TxGNN Prediction Score | 99.98% |
| Evidence Level | L4 |
| UK Market Status | Not marketed |
| Number of Marketing Authorisations | 0 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available (DG002, High severity). Based on known information, Cyclizine belongs to the piperazine class of first-generation H1-receptor antagonists, a pharmacological group whose efficacy in antiemetic/antihistamine use is well established, and which may mechanistically extend to allergic conditions.
Allergic urticaria is a classical H1-mediated hypersensitivity reaction, and antihistamines are the standard pharmacological class used for such conditions, so a class-level mechanistic link to cyclizine is biologically plausible. However, the one literature record retrieved for this pairing (PMID 8573923) is a mechanistic study of solar urticaria action spectra and does not evaluate cyclizine treatment or efficacy directly — it supports disease-mechanism context rather than drug-specific evidence.
Given the absence of any clinical trial or drug-specific efficacy literature, this prediction should currently be treated as a class-level pharmacological hypothesis rather than an evidence-backed repurposing candidate.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 8573923 | 1995 | Mechanistic/physiological study (non-interventional) | Dermatology (Basel, Switzerland) | Characterises action/inhibition/augmentation spectra in solar urticaria; does not evaluate cyclizine treatment directly, provides disease-mechanism context only |
UK Market Information
No UK marketing authorisations are currently on record for this drug (market status: Not marketed; total licences: 0).
Safety Considerations
Please refer to the SmPC and BNF for safety information. Report suspected adverse reactions via the Yellow Card Scheme.
(Note: TFDA/MHRA-equivalent warnings and contraindications data are recorded as a Blocking data gap — DG001 — and drug interaction search returned no results, so no drug-specific safety details can be listed here.)
Conclusion and Next Steps
Decision: Hold
Rationale:
- The prediction rests on class-level pharmacological plausibility (H1-antagonism) rather than drug-specific evidence — evidence level is L4 with zero clinical trials and only one indirectly relevant, non-interventional publication. In addition, a Blocking-severity data gap (DG001: missing warnings/contraindications) currently prevents this candidate from entering the S1 safety pre-assessment stage at all.
To proceed, the following is needed:
- Resolve DG001: obtain SmPC/label warnings and contraindications (source: TFDA/MHRA equivalent) to unblock S1 safety pre-assessment
- Resolve DG002: obtain confirmed mechanism of action data from DrugBank
- Identify drug-specific evidence (case series, observational data, or trials) evaluating cyclizine — not just antihistamines as a class — in urticaria
- Optionally evaluate the secondary candidate “headache disorder” (rank 6, also L4/S1), which has more literature (5 papers) tied to the historical ergotamine–caffeine–cyclizine combination product (Migril), though this too lacks cyclizine-specific efficacy trials
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.