Phenylephrine
| Evidence Level: L3 | Predicted Indications: 3 |
Table of Contents
Phenylephrine: From Original Indication (Not Recorded) to Nasal Cavity Disease
One-Sentence Summary
Phenylephrine is a selective alpha-1 adrenergic agonist. It is marketed in South Africa in 20 registered products, but the approved indications are not recorded in the data supplied. The TxGNN model predicts it may be effective for nasal cavity disease, with 8 registered clinical trials and 8 publications retrieved. Most of this evidence is indirect, and the prediction may simply restate an existing topical decongestant use.
Quick Overview
| Item | Content |
|---|---|
| Predicted New Indication | Nasal cavity disease |
| TxGNN Prediction Score | 99.97% |
| Evidence Level | L3 |
| South Africa Market Status | Marketed |
| Number of SAHPRA Registrations | 20 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Phenylephrine is a selective alpha-1 adrenergic agonist. Its action on the nasal mucosa is vasoconstriction, which reduces swelling, congestion and mucosal bleeding. This fits nasal disease well.
The original indication is not recorded in the data supplied, and neither are the licensed indications of the South African products. The predicted use overlaps with established topical decongestant use, so it may already be on-label or well known rather than truly new. The registered product label should be checked before this is treated as repurposing.
Detailed mechanism-of-action data from DrugBank are also unavailable. The mechanistic reasoning above rests on the drug’s known pharmacology, not on a retrieved record.
The two lower-ranked predictions are speculative and have no trials or literature:
- Acute laryngopharyngitis (score 99.97%): vasoconstriction might reduce upper-airway mucosal oedema, but topical decongestants are not an established treatment for it.
- Trigeminal autonomic cephalalgia (score 99.30%): a vasoconstrictor might act on the nasal congestion seen in cluster headache, but not on the pain mechanism. Pressor effects of systemic phenylephrine would also be a safety concern.
Clinical Trial Evidence
Most trials below do not clearly test phenylephrine on a nasal disease. Relevance grades are from the evidence review (B = partial, C = weak).
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT03380715 | N/A | Completed | 106 | Co-phenylcaine (lidocaine plus phenylephrine) nasal spray vs nebulization before rigid nasoendoscopy. It uses a phenylephrine product in the nasal cavity, but the endpoint is procedural tolerance, not disease treatment. |
| NCT00562120 | Phase 2 | Completed | 21 | Placebo-controlled crossover study of an H3 antagonist on congestion after nasal allergen challenge. Phenylephrine involvement is unconfirmed, so manual verification is needed. |
| NCT03228914 | Phase 4 | Completed | 20 | Topical 0.05% oxymetazoline vs a comparator on blood loss and surgical view in sinus surgery. It is a nasal vasoconstrictor comparison, and the comparator is unverified. |
| NCT06443255 | Phase 3 | Completed | 16 | Cocaine vs lidocaine/xylometazoline vs saline for intranasal analgesia. Phenylephrine is not evident in the arms, so it is not direct evidence. |
| NCT02993770 | N/A | Unknown | 120 | Endonasal vs external dacryocystorhinostomy. This is a surgical technique comparison. |
| NCT06457100 | Phase 1/2 | Active, not recruiting | 60 | Perioperative IV esmolol vs lidocaine in sinus surgery. It is unrelated to topical phenylephrine. |
| NCT03962634 | Phase 2 | Terminated | 3 | Kovanaze (tetracaine/oxymetazoline) nasal mist vs articaine for dental anaesthesia. |
| NCT04104789 | Phase 2 | Withdrawn | 0 | Kovanaze vs articaine. It was withdrawn with no participants enrolled. |
No SANCTR or PACTR registrations were identified.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 15854186 | 2005 | RCT | Int J Clin Pract | Co-phenylcaine spray vs placebo before flexible nasendoscopy (98 patients). Pain and discomfort were minimal in both groups, with no significant difference in pain. |
| 25133491 | 2014 | RCT | PLoS One | Topical tranexamic acid on bleeding and surgical field in sinus surgery for chronic rhinosinusitis. It does not involve phenylephrine and is only contextual. |
| 40899890 | 2025 | Experimental and clinical study | Vestn Otorinolaringol | Safety and efficacy of Polydexa spray with phenylephrine in acute rhinosinusitis. It addresses the lack of toxicity data for this combination. |
| 37184554 | 2023 | Cohort | Vestn Otorinolaringol | Endoscopic assessment of the nasal mucosa after Polydexa with phenylephrine spray (dexamethasone, neomycin, polymyxin B, phenylephrine) in chronic nasal disease after surgery. |
| 37970776 | 2023 | Review | Vestn Otorinolaringol | Pathogenesis-based approach to inflammatory diseases of the nose and sinuses, including reducing mucosal hyperaemia and swelling. |
| 9780066 | 1998 | Cohort | Int J Pediatr Otorhinolaryngol | Acoustic rhinometry of the nasal cavity and nasopharynx after adenoidectomy and tonsillectomy. |
| 1375136 | 1992 | In vitro | Clin Otolaryngol Allied Sci | Effects of drugs used in nasal disease on ciliary beat frequency in vitro. |
| 7378007 | 1980 | Case report | Arch Ophthalmol | Cocaine toxicity during dacryocystorhinostomy. One patient also reacted to intranasal phenylephrine. |
South Africa Market Information
There are 20 SAHPRA registrations. Five are shown below. Approved indication text and Essential Medicines List status are not recorded in the data supplied.
| Registration Number | Product Name | Dosage Form |
|---|---|---|
| G2971 | Celestone Injection | Injection |
| C739 | Sinu-flu (was Universal cold & flu) | Tablet |
| 28/5.8/0696 | Degoran Fizzy Effervescent Tablets | Effervescent tablet |
| X/5.8/383 | Adco-sinal ns | Capsule |
| G1235 (ACT 101) | Famucaps | Capsule |
Across all registrations, forms include injection, tablet, effervescent tablet, capsule, suspension, drops, syrup, sachet and inhaler.
Safety Considerations
Please refer to the SAHPRA-approved Professional Information (PI) for safety information. Report adverse drug reactions to SAHPRA.
The only safety signal in the retrieved literature is a 1980 case report. Cocaine used intranasally is dangerous with sympathomimetic drugs, and one patient had an additional reaction to intranasal phenylephrine (PMID 7378007). This supports caution with systemic pressor effects, particularly in patients with hypertensive cardiovascular disease.
Conclusion and Next Steps
Decision: Hold
Rationale: The model score is very high (99.97%), and the mechanism fits nasal congestion. However, the trials and papers found are mostly indirect: procedural nasal sprays, other decongestants, or combination products. No study clearly shows phenylephrine alone treating a nasal disease. The indication may already be on-label, so this may not be true repurposing. The evidence stage is currently a research question.
To proceed, the following is needed:
- SAHPRA Professional Information for the registered products, to confirm licensed indications and to obtain warnings and contraindications. This is a blocking gap for safety screening.
- Confirmation of whether nasal decongestion is already an approved use, which would make the prediction non-novel.
- Manual review of NCT00562120 and NCT03228914 to see whether phenylephrine was actually used.
- Mechanism of action data from DrugBank.
- Drug interaction data, as none were found.
- If pursued, a review of the phenylephrine-specific papers (PMIDs 40899890 and 37184554) for study design and outcomes.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.