Flurbiprofen
| Evidence Level: L5 | Predicted Indications: 10 |
Table of Contents
Flurbiprofen: From Rheumatoid Arthritis and Osteoarthritis to Ankylosing Spondylitis
One-Sentence Summary
Flurbiprofen is a non-steroidal anti-inflammatory drug (NSAID) originally used for rheumatoid arthritis, osteoarthritis and other joint disorders. The TxGNN model predicts it may be useful for ankylosing spondylitis, the best-supported of its top ten predictions. There are no registered clinical trials, but the data compiled for this report include 20 publications, many of them older double-blind comparison studies.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Rheumatoid arthritis, osteoarthritis, arthropathy (the Singapore licence records contain no indication text) |
| Predicted New Indication | Ankylosing spondylitis (the report focuses on this candidate; the model's top-ranked prediction, acromesomelic dysplasia, Hunter-Thompson type, has no supporting evidence) |
| TxGNN Prediction Score | 99.97% (ankylosing spondylitis); 99.99% (top-ranked prediction) |
| Evidence Level | L3 (older comparative studies and reviews, no registered trials) |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 3 |
| Recommended Decision | Proceed with Guardrails |
Why is This Prediction Reasonable?
Detailed mechanism of action data is not available in the compiled data. Based on known pharmacology, flurbiprofen is an NSAID that inhibits COX-1 and COX-2, which reduces prostaglandin-mediated inflammation and pain. This is the established mechanism of symptomatic relief in axial spondyloarthritis.
Ankylosing spondylitis is an inflammatory rheumatic disease whose symptoms (pain, stiffness, tenderness of the joints) are the same ones flurbiprofen is already used to relieve in rheumatoid arthritis and osteoarthritis. This is therefore closer to an extension within the same therapeutic class than a true repurposing. NSAIDs are established first-line therapy for this condition.
The other top-ranked predictions are mostly rare genetic skeletal or developmental syndromes (for example brachydactyly-syndactyly syndrome, brachyolmia and pseudoachondroplasia). No plausible mechanistic link was identified for them, and they have no trials or literature. They remain model predictions only (L5, Hold). Spondyloarthropathy susceptibility (L4) overlaps with ankylosing spondylitis, and its support is inferred from the same evidence.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
Most of the literature predates 2000. The study types below were inferred largely from titles and abstracts.
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 3963017 | 1986 | Double-blind randomized comparison | Am J Med | Flurbiprofen 200 mg/day vs phenylbutazone in 90 patients over 26 weeks: equally effective in controlling pain and symptoms |
| 3963018 | 1986 | Double-blind randomized comparison | Am J Med | Flurbiprofen vs indomethacin in 57 patients over 26 weeks: effective in controlling pain and associated symptoms |
| 71969 | 1977 | Double-blind randomized comparison | Curr Med Res Opin | Flurbiprofen vs indomethacin in 26 patients over 6 weeks: equally effective for pain and tenderness |
| 329422 | 1977 | Double-blind randomized comparison | South Med J | Flurbiprofen vs indomethacin in 26 patients: equal relief of joint pain and tenderness |
| 324773 | 1977 | Double-blind randomized comparison | Eur J Clin Pharmacol | Flurbiprofen vs phenylbutazone in 27 patients: equally effective; overall improvement favoured phenylbutazone but not significantly |
| 4611579 | 1974 | Double-blind cross-over trial | Br Med J | Flurbiprofen vs phenylbutazone in 35 patients: well tolerated, efficacy approaching phenylbutazone |
| 7003449 | 1980 | Double-blind cross-over comparison | N Z Med J | Flurbiprofen vs naproxen in 30 patients: no significant efficacy difference; side effects more frequent with flurbiprofen |
| 4595274 | 1974 | Double-blind cross-over comparison | Ann Rheum Dis | Indomethacin, flurbiprofen and placebo compared in ankylosing spondylitis (no abstract available) |
| 391529 | 1979 | Review | Drugs | Pharmacology and therapeutic use of flurbiprofen in rheumatic diseases, including ankylosing spondylitis |
| 3963024 | 1986 | Pooled safety analysis | Am J Med | Liver and kidney data pooled from nine phase III trials (1,677 patients) in ankylosing spondylitis, osteoarthritis and rheumatoid arthritis |
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN14364P | Strepsils MaxPro Honey and Lemon lozenges 8.75mg | Lozenge | Not stated in the licence record |
| SIN15370P | Strepsils Max Pro Direct Spray 8.75mg per dose | Spray | Not stated in the licence record |
| SIN12090P | Acustop Cataplasma Plaster 40 mg/sheet | Patch | Not stated in the licence record |
All three licences are valid single-ingredient products. They are a lozenge, a spray and a patch (topical or local routes), not the systemic oral forms used in the ankylosing spondylitis studies above. Route compatibility for the predicted indication has not been assessed.
Safety Considerations
- Contraindications (from the knowledge graph, not label text): hypertension, kidney disease, liver disease, gallbladder disease, peptic ulcer disease (including active), blood coagulation disease, myocardial infarction, coronary thrombosis, cardiovascular and heart disease, hemoglobinopathy, substance abuse/dependence, and pyoureter.
- Drug Interactions: 100 interactions were found in the interaction databases; the 20 reviewed include mostly moderate ones:
- Corticosteroids: hydrocortisone, dexamethasone, betamethasone, triamcinolone, budesonide
- Aspirin (acetylsalicylic acid)
- Mesalazine and balsalazide
- Antidiabetics: metformin, glimepiride, chlorpropamide
- Aprepitant
- Potassium citrate and potassium bicarbonate
- Bowel preparations: picosulfuric acid, sodium sulfate, polyethylene glycol with electrolytes
- Minor interactions: famotidine, cimetidine, linaclotide
- One study in the literature set (PMID 7003449) noted more frequent side effects with flurbiprofen than naproxen. The pooled phase III analysis (PMID 3963024) examined liver and kidney assay data.
Package insert warnings were not available, so please refer to the package insert for complete safety information.
Conclusion and Next Steps
Decision: Proceed with Guardrails (for ankylosing spondylitis only; the other nine predictions remain on Hold)
Rationale:
- Several double-blind comparison studies show flurbiprofen relieves ankylosing spondylitis symptoms about as well as indomethacin, phenylbutazone and naproxen. NSAIDs are also an established treatment class for this condition. However, the evidence is old, small and not registered, and there are no trials of recent design.
- The Singapore-registered products are topical or local forms, and the top-ranked rare skeletal disease predictions have no supporting evidence.
To proceed, the following is needed:
- HSA package insert warnings and contraindications (a blocking gap for safety screening)
- Mechanism of action data from DrugBank
- Confirmation of the study designs and outcomes of the older comparison studies, with a review of newer evidence for NSAIDs in axial spondyloarthritis
- Assessment of whether a systemic oral formulation is registered or needed in Singapore
- A safety plan for patients with cardiovascular, renal, hepatic, gastrointestinal bleeding or coagulation risk, and a review of interactions with corticosteroids, aspirin and antidiabetic drugs
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.