Guaifenesin
| Evidence Level: L2 | Predicted Indications: 10 |
Table of Contents
Guaifenesin: From Expectorant Use to Nasal Cavity Disease
One-Sentence Summary
Guaifenesin is a mucolytic/expectorant that reduces the viscosity of respiratory secretions, though this evidence pack contains no formal approved indication text or active UK marketing authorisation for the drug. The TxGNN model predicts it may be effective for Nasal Cavity Disease, with 1 clinical trial and 2 publications currently supporting this direction.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not documented in this evidence pack (no UK licences on file); the repurposing rationale describes guaifenesin only as an expectorant/mucolytic |
| Predicted New Indication | Nasal Cavity Disease |
| TxGNN Prediction Score | 99.98% |
| Evidence Level | L2 |
| 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 for guaifenesin in this evidence pack. Based on the repurposing rationale that is available, guaifenesin is an expectorant that lowers airway mucus viscosity and promotes serous secretion, thereby facilitating clearance of retained mucus. This mechanism is not aimed directly at nasal pathology but is theoretically extendable to conditions characterised by mucus retention.
Nasal Cavity Disease covers conditions such as chronic rhinitis, where excess or thickened mucus contributes to symptom burden. Since guaifenesin’s established pharmacological action is mucus thinning and clearance in the respiratory tract more broadly, a mechanistic rationale for benefit in nasal mucus retention is plausible, even though the drug’s original, formally approved indication is not recorded in this dataset.
This rationale is supported by a completed paediatric pilot trial (see below), which directly tested oral guaifenesin in chronic rhinitis, lending early clinical, not merely theoretical, support to the prediction.
Clinical Trial Evidence
| Trial Number | Phase | Status | Enrolment | Key Findings |
|---|---|---|---|---|
| NCT01364467 | Phase 2 | Completed | 30 | 14-day randomised, placebo-controlled, parallel-group, masked pilot trial of oral guaifenesin in paediatric chronic rhinitis (ages 7–18), assessing nasal symptom relief via the SN-5 survey, nasal airway volume, and biophysical properties of nasal secretion |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 9065342 | 1997 | Review | American Journal of Rhinology | Case series/review of sinusitis management in adult cystic fibrosis (n=22), discussing medical and surgical approaches including mucoactive therapy |
| 12487405 | 2002 | Review | Logopedics, Phoniatrics, Vocology | Review of treatment strategies for hidden respiratory allergies in voice users; notes decongestant/guaifenesin combinations as a therapeutic option over antihistamines |
UK Market Information
No active UK marketing authorisation is recorded for guaifenesin in this evidence pack (0 licences on file; market status: Not marketed).
Safety Considerations
Please refer to the SmPC and BNF for safety information. Report suspected adverse reactions via the Yellow Card Scheme.
Conclusion and Next Steps
Decision: Hold
Rationale:
- Evidence is limited to a single small, completed Phase 2 paediatric pilot trial (n=30) and two indirectly related reviews; there is no UK marketing authorisation on file for guaifenesin, and the underlying safety label data (warnings, contraindications) required for an initial safety assessment is a blocking data gap in this pack.
To proceed, the following is needed:
- UK SmPC/label data — key warnings and contraindications (currently a blocking data gap)
- Confirmed mechanism of action (MOA) documentation
- Confirmation of any existing or planned UK licensing pathway for guaifenesin
- A larger, adequately powered replication trial in chronic rhinitis/nasal cavity disease beyond the existing n=30 pilot
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.