Tulobuterol

證據等級: L5

預測適應症: 10 個

Tulobuterol: From Obstructive Airways Disease to Bronchitis

One-Sentence Summary

Tulobuterol is a selective β₂-adrenergic receptor agonist (long-acting bronchodilator), with established use for bronchial asthma and obstructive airways disease in Japan, Korea, and China — most notably as the Hokunalin transdermal patch formulation. The TxGNN model predicts it may be effective for Bronchitis, with 1 clinical trial and 4 publications currently supporting this direction. The mechanistic rationale is strong: tulobuterol directly relaxes bronchial smooth muscle and has been shown to enhance mucociliary clearance — both central to bronchitis pathophysiology.

Quick Overview

Item	Content
Original Indication	Bronchial asthma / Obstructive airways disease (approved in Japan, Korea, China)
Predicted New Indication	Bronchitis
TxGNN Prediction Score	99.998%
Evidence Level	L1
India Market Status	✗ Not Marketed
Number of Registrations	0
Recommended Decision	Proceed with Guardrails

Why is This Prediction Reasonable?

Currently, detailed mechanism of action data is not available in this evidence pack. Based on known information from the literature, tulobuterol is a selective β₂-adrenergic receptor agonist that relaxes bronchial smooth muscle, reduces airway resistance, and is delivered via a transdermal patch (Hokunalin/Atock) providing stable 24-hour drug release. This chronotherapeutic design specifically targets the early-morning dip in respiratory function by timing peak plasma concentration to coincide with peak symptom severity.

Bronchitis — whether acute or chronic — is pathologically characterized by airway inflammation, mucus hypersecretion, and bronchospasm. Tulobuterol addresses all three mechanisms applicable to smooth muscle: it lowers bronchomotor tone, improves expiratory flow, and has been directly shown to enhance mucociliary clearance. PMID 2884705 (Matthys et al., 1987) prospectively demonstrated that tulobuterol significantly improved total, central, and peripheral bronchial mucociliary clearance in patients with chronic obstructive bronchitis in a double-blind crossover design — directly linking the drug’s pharmacology to the pathological mechanism of bronchitis.

The clinical overlap further supports this prediction. Chronic bronchitis is one of the two defining phenotypes of COPD, an indication in which tulobuterol already has multiple completed RCTs and licensed approvals. An active Phase 4 RCT (NCT06411925) is currently enrolling 296 patients with acute bronchitis using the Atock Dry Syrup formulation, providing prospective confirmation that this indication is being formally pursued.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrollment	Key Findings
NCT06411925	Phase 4	Recruiting	296	Multi-center, randomized, double-blind, active-controlled, non-inferiority RCT evaluating efficacy and safety of Atock Dry Syrup in acute bronchitis patients (est. completion Sep 2027)

Literature Evidence

PMID	Year	Type	Journal	Key Findings
2884705	1987	Pharmacological/Clinical Study	Respiration	Double-blind crossover study (n=10) showing tulobuterol significantly improved total, central, and peripheral mucociliary clearance in patients with chronic obstructive bronchitis; comparable to fenoterol
2861899	1985	Clinical Study (Controlled Trial)	Clinical Therapeutics	Evaluated tulobuterol as a β₂-agonist in obstructive airways disease; chronic bronchitis and emphysema discussed alongside asthma; individual patient response variability noted
23527972	2013	Review	Chinese Journal of Pediatrics	Clinical application of transdermal β₂-agonists including tulobuterol patch in childhood wheezing diseases; supports pediatric bronchitis-related use
2983286	1985	Pharmacological Study	Orvosi Hetilap	Mechanistic study on β-mimetic effects on bronchial mucus transport; provides the pharmacological basis for mucociliary clearance improvement relevant to bronchitis

India Market Information

Tulobuterol is currently not marketed in India. No drug registrations are on record with the Indian regulatory authority (CDSCO). The drug holds established approvals in Japan (Hokunalin Tape, Atock), Korea, and China as a transdermal patch and oral/inhaled formulations. These existing approvals in Asia-Pacific markets may serve as regulatory precedent for a future India submission.

Safety Considerations

Please refer to the package insert for safety information.

Formal warning and contraindication data were not available in this evidence pack. As a β₂-adrenergic agonist class, clinicians should review class-specific precautions — including cardiovascular effects (tachycardia, palpitations), skeletal muscle tremor, hypokalemia at high doses, and caution in patients with hyperthyroidism or cardiac arrhythmias — from the Japanese or Korean product labeling prior to any clinical application.

Conclusion and Next Steps

Decision: Proceed with Guardrails

Rationale: The TxGNN prediction score is near-perfect (99.998%), the mechanistic link between β₂-agonist activity and bronchitis is well-established, a Phase 4 RCT is actively recruiting for this exact indication, and multiple literature sources directly support bronchodilator use in bronchitis. The L1 evidence rating reflects the robustness of the broader obstructive airways disease evidence base.

To proceed, the following is needed:

Retrieve full CDSCO or equivalent package insert (India or Japan/Korea) to complete the S1 safety screening — currently a blocking data gap
Confirm detailed MOA data via DrugBank API (DB12248) to complete mechanistic analysis
Monitor NCT06411925 (expected completion September 2027) for Phase 4 acute bronchitis efficacy and safety results
Assess India registration feasibility: evaluate import pathway or local manufacturing requirements given current not-marketed status
Use Japan PMDA and Korea MFDS existing approvals as regulatory precedent to support a CDSCO dossier
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.