Salmeterol
| Evidence Level: L1 | Predicted Indications: 10 |
Table of Contents
Salmeterol: From Asthma and Emphysema to Bronchitis
One-Sentence Summary
Salmeterol is a long-acting beta2-adrenoceptor agonist, originally used for pulmonary emphysema and asthma (intrinsic and allergic). The TxGNN model predicts it may be effective for bronchitis (mainly chronic bronchitis within COPD), with 9 clinical trials and 20 publications currently supporting this direction. Most of this evidence is in COPD populations, so the new indication is a close extension of the existing ones rather than a distant repurposing.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Pulmonary emphysema, intrinsic asthma, allergic asthma (the Singapore licence records contain no indication text) |
| Predicted New Indication | Bronchitis |
| TxGNN Prediction Score | 99.92% |
| Evidence Level | L1 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 8 |
| Recommended Decision | Proceed with Guardrails |
Why is This Prediction Reasonable?
Salmeterol is a long-acting beta2-adrenoceptor agonist. It relaxes airway smooth muscle and produces sustained bronchodilation. Detailed mechanism of action data are not available in the data compiled for this report, so this description relies on its known drug class.
Chronic bronchitis is a major COPD phenotype, and emphysema (an existing indication) is the other. The same airflow obstruction therefore underlies both. Salmeterol may also improve mucociliary and cough clearance. A small placebo-controlled study in 14 patients with mild-to-moderate chronic bronchitis (PMID 15970448) examined exactly this effect.
Several Phase 3 COPD trials include a salmeterol arm, so the prediction rests on direct clinical evidence and is not only a model output.
Clinical Trial Evidence
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT00268177 | Phase 3 | Completed | 130 | Salmeterol/fluticasone 50/500 mcg vs placebo on airway inflammation in COPD (13 weeks) |
| NCT02173691 | Phase 3 | Completed | 584 | Tiotropium vs salmeterol aerosol vs placebo; 6-month bronchodilator efficacy and safety in COPD |
| NCT00269087 | Phase 3 | Completed | 122 | Long-term (56-week) safety of salmeterol/fluticasone 50/500 µg in COPD (chronic bronchitis, emphysema) |
| NCT00269126 | Phase 3 | Completed | 150 | Comparison of two medicines in COPD over 18 weeks (the link to salmeterol cannot be confirmed from the available data) |
| NCT00064415 | Phase 3 | Completed | 799 | 12-month safety of arformoterol vs an active control in COPD (indirect evidence for salmeterol) |
| NCT00064402 | Phase 3 | Completed | 741 | Arformoterol, placebo- and active-controlled, 12-week bronchodilator effect in COPD (indirect evidence for salmeterol) |
| NCT00403286 | Phase 2 | Completed | 457 | Dose-finding of fluticasone/formoterol against Advair (salmeterol/fluticasone) in COPD (limited relevance) |
| NCT01361984 | Phase 4 | Unknown | 20 | Nebulized arformoterol vs salmeterol dry-powder inhaler in COPD (small study) |
| NCT00233051 | NA | Terminated | 20 | Sputum inflammatory markers as a biomarker of drug response in COPD (limited value) |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 15970448 | 2006 | RCT/Clinical study | Pulm Pharmacol Ther | Effect of salmeterol vs placebo on mucociliary and cough clearance in 14 patients with chronic bronchitis |
| 17557771 | 2007 | RCT | Thorax | Salmeterol/fluticasone and airway inflammation in COPD |
| 12970006 | 2003 | Clinical trial | Chest | Efficacy and safety of fluticasone 250 µg/salmeterol 50 µg in the Diskus inhaler vs placebo and the single agents in COPD |
| 19124357 | 2008 | Clinical trial | Ther Adv Respir Dis | One-year safety and tolerance of arformoterol and salmeterol in COPD |
| 17196106 | 2006 | Meta-analysis | Respir Res | Pooled analysis: salmeterol 50 mcg twice daily improved clinically relevant outcomes in COPD vs placebo/usual therapy |
| 15329047 | 2004 | Review | Drugs | Review of salmeterol/fluticasone in COPD, including COPD associated with chronic bronchitis |
| 9916607 | 1998 | Open-label study | Clin Ther | Inhaled salmeterol vs oral theophylline in mild-to-moderate COPD (efficacy, tolerability, quality of life) |
| 19210134 | 2009 | Cohort | Curr Med Res Opin | Healthcare use and costs in chronic bronchitis patients starting fluticasone/salmeterol vs other inhaled maintenance therapies |
| 12236842 | 2002 | Review | Br J Clin Pharmacol | Long-acting beta2-agonists and inhaled corticosteroid-sparing effects, with a caution about anti-inflammatory adequacy |
| 25515181 | 2015 | Guideline | Basic Clin Pharmacol Toxicol | Finnish guideline for stable COPD diagnosis and pharmacotherapy |
Singapore Market Information
All eight licences are valid. They are all salmeterol-containing products.
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN11531P | SERETIDE EVOHALER 25/250 mcg | Aerosol, spray | Not recorded |
| SIN11030P | SERETIDE 50/100 ACCUHALER | Powder, metered | Not recorded |
| SIN16909P | SALFLUMIX EASYHALER 50µG/250µG/dose | Powder, metered | Not recorded |
| SIN16910P | SALFLUMIX EASYHALER 50µG/500µG/dose | Powder, metered | Not recorded |
| SIN11032P | SERETIDE 50/500 ACCUHALER | Powder, metered | Not recorded |
Three further licences are not shown: SERETIDE EVOHALER 25/50 mcg (SIN11529P), SERETIDE 50/250 ACCUHALER (SIN11031P) and SERETIDE EVOHALER 25/125 mcg (SIN11530P).
Safety Considerations
- Contraindications suggested by the knowledge graph (not label text): hypertension, long QT syndrome (including familial), epilepsy, hyperglycaemia, pituitary hormone deficiencies, herpes simplex keratitis, thymus gland disease, and osteoporosis. These should be verified against the approved package insert.
- Drug interactions: 100 interactions were identified. Among those retrieved, the notable ones are:
- Major: clarithromycin.
- Moderate: epinephrine, famotidine, acarbose, isometheptene, dolasetron, diethylpropion, and several antidiabetic agents (albiglutide, alogliptin, canagliflozin, chlorpropamide, dapagliflozin, dulaglutide, empagliflozin).
- Minor: corticosteroids (hydrocortisone, dexamethasone, budesonide, beclomethasone, betamethasone, triamcinolone).
- Safety literature: Cochrane reviews (PMIDs 30521673, 23543548) report serious adverse event concerns with regular long-acting beta2-agonists in asthma. Salmeterol should not be used as monotherapy in asthma and should be combined with an inhaled corticosteroid.
Please refer to the package insert for the full warnings.
Conclusion and Next Steps
Decision: Proceed with Guardrails
Rationale: Multiple completed Phase 3 trials in COPD and chronic bronchitis include salmeterol, and direct data show an effect on mucociliary clearance. Bronchitis is a close extension of the existing emphysema and asthma indications, so the evidence is strong. The cardiovascular and metabolic contraindication signals and the monotherapy caution in asthma require safeguards.
To proceed, the following is needed:
- Singapore package insert warnings, contraindications and approved indication text, which are missing from the data compiled for this report
- Detailed mechanism of action data
- Confirmation of which Singapore products carry a COPD or chronic bronchitis indication (the licence records show salmeterol only in combination with fluticasone)
- A clear definition of the target population (chronic bronchitis within COPD) and confirmation of how many of the listed trials directly test salmeterol
- A safety monitoring plan for patients with cardiovascular disease, QT prolongation, diabetes or epilepsy, and for those taking strong CYP3A4 inhibitors such as clarithromycin
Other Predicted Indications (Summary)
| Rank | Predicted Indication | Evidence Level | Decision | Comment | |---|---|---|---|---| | 3 | Obstructive lung disease | L1 | Proceed with Guardrails | Essentially the original indication (COPD/asthma), supported by large Phase 3/4 trials | | 5 | Asthma | L1 | Proceed with Guardrails | Already a labelled use; not for monotherapy | | 2 | Respiratory malformation | L4 | Hold | Indirect, symptomatic link only (e.g. cystic fibrosis) | | 7 | Atopic eczema | L4 | Hold | Preclinical and mechanistic data only; no clinical trials | | 8 | Bronchial neoplasm | L4 | Hold | Trials matched by term only; no anti-tumour evidence | | 9 | Hyperlucent lung | L4 | Hold | A single case report | | 4, 6, 10 | Rienhoff syndrome; asthma-related traits, susceptibility to; compensatory emphysema | L5 | Hold | Model prediction only, with no supporting studies |
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.