Propranolol
| Evidence Level: L2 | Predicted Indications: 6 |
Table of Contents
- Propranolol
- Propranolol: From Cardiovascular Indications to Cardiomyopathy (Hypertrophic Obstructive Subtype)
Using the report template above (no additional skill needed — this is a defined content-generation task with an explicit spec already provided).
Note on indication selection: Among the 6 TxGNN candidates, the top-ranked ones by raw score (distal myopathy, congenital myopathy, chondroma) have zero evidence and the rationale text itself states they lack biological plausibility (Hold, L5). The only candidate with real clinical evidence is cardiomyopathy (rank 6, L2, “Proceed with Guardrails”) — driven by decades of hypertrophic obstructive cardiomyopathy (HOCM) trials. This report focuses on that candidate as the clinically meaningful one; the others are noted briefly for completeness.
Propranolol: From Cardiovascular Indications to Cardiomyopathy (Hypertrophic Obstructive Subtype)
One-Sentence Summary
Propranolol is a non-selective beta-blocker with long-established cardiovascular uses (hypertension, angina, arrhythmias). The TxGNN model predicts it may be effective for Cardiomyopathy — most specifically hypertrophic obstructive cardiomyopathy (HOCM) — with 3 clinical trials and 20 publications currently supporting this direction, including historical double-blind RCTs.
Note: TxGNN’s highest-scoring candidates for this drug (distal myopathy Tateyama type, congenital myopathy with thin filament excess, chondroma) returned no supporting evidence and are explicitly flagged in the model rationale as lacking biological plausibility. They remain at “Hold” and are not discussed further.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not recorded in source registry (data gap); propranolol is internationally established for hypertension, angina pectoris and cardiac arrhythmias |
| Predicted New Indication | Cardiomyopathy (evidence base concentrated in hypertrophic obstructive cardiomyopathy) |
| TxGNN Prediction Score | 99.12% |
| Evidence Level | L2 |
| UK Market Status | Not marketed (per this dataset — see caveat under UK Market Information) |
| Number of Marketing Authorisations | 0 |
| Recommended Decision | Proceed with Guardrails |
Why is This Prediction Reasonable?
Detailed mechanism-of-action data was flagged as a data gap in the structured dataset (DG002). However, the evidence base itself is explicit: propranolol is a non-selective beta-adrenergic receptor blocker (β1 and β2), reducing heart rate, myocardial contractility and cardiac output. In hypertrophic obstructive cardiomyopathy, this negative inotropic/chronotropic action lowers left ventricular outflow tract (LVOT) pressure gradient — the central pathophysiological problem in HOCM.
This is not a novel mechanistic leap: propranolol’s classical cardiovascular indications (hypertension, angina, arrhythmia) already exploit the same beta-blockade pathway. The extension to HOCM is a within-class, within-mechanism application rather than a repurposing into an unrelated therapeutic area, and it is supported by clinical use dating back to the 1970s–1990s (double-blind RCTs, haemodynamic catheterisation studies, and combination therapy trials with nifedipine/disopyramide).
The evidence is weaker and more mixed for related but distinct entities — dilated cardiomyopathy (haemodynamic deterioration risk noted in some cohorts) and cirrhotic cardiomyopathy (conflicting effects on QTc vs renal/circulatory function) — so the “Proceed with Guardrails” recommendation should be understood as applying most confidently to the HOCM subtype, not cardiomyopathy as a whole.
Clinical Trial Evidence
| Trial Number | Phase | Status | Enrolment | Key Findings |
|---|---|---|---|---|
| NCT05427474 | Phase 3 | Unknown | 90 | Propranolol + gabapentin for paroxysmal sympathetic hyperactivity in traumatic brain injury (ICU); indirect relevance — not cardiomyopathy itself |
| NCT05019027 | Phase 4 | Enrolling by invitation | 20 | N-of-1 deprescribing trial of beta-blockers in transthyretin cardiac amyloidosis; safety/usage data rather than efficacy proof |
| NCT04767061 | Phase 4 | Completed | 9 | N-of-1 deprescribing trial of beta-blockers in HFpEF; physical function outcomes |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 4586631 | 1973 | RCT | British Heart Journal | Double-blind trial of propranolol vs practolol in hypertrophic cardiomyopathy |
| 3673167 | 1987 | RCT/Combination study | Zeitschrift für Kardiologie | Nifedipine + propranolol combination in HCM over 6–24 months |
| 7200796 | 1982 | Cohort/Haemodynamic | British Heart Journal | Haemodynamic effects of nifedipine and propranolol in HOCM |
| 1611637 | 1992 | Cohort/Exercise study | Cardiology | Effect of propranolol and disopyramide on LV function at rest and exercise in HCM |
| 7191199 | 1980 | Cohort/Observational | Am J Cardiology | Propranolol and arrhythmia in hypertrophic cardiomyopathy |
| 7192151 | 1980 | Cohort/Haemodynamic | British Heart Journal | Propranolol effects on myocardial oxygen consumption and haemodynamics in HOCM |
| 6686544 | 1983 | Cohort/Haemodynamic | European Heart Journal | Diastolic stiffness: propranolol vs verapamil in HCM |
| 2920304 | 1989 | Cohort/Echocardiographic | Canadian J Cardiology | Disopyramide + propranolol combination in HCM |
| 3189143 | 1988 | Cohort/Haemodynamic | American Heart Journal | Acute haemodynamic effects of pindolol vs propranolol in dilated cardiomyopathy |
| 8989641 | 1996 | Cohort/Haemodynamic | J Cardiac Failure | Predictors of intolerance and long-term propranolol effects in dilated cardiomyopathy |
UK Market Information
No marketing authorisation records are present in this dataset (total_licenses = 0, licenses = []). This is a known data gap rather than confirmation of non-availability — propranolol is a long-established generic beta-blocker, and current UK licensing status (including brand/generic products and their approved indications) should be verified directly against the MHRA product database and current BNF entry before any decision is finalised.
Safety Considerations
Please refer to the SmPC and BNF for safety information. Report suspected adverse reactions via the Yellow Card Scheme.
(Key warnings, contraindications and drug interaction data were all flagged as data gaps in this evidence pack — DG001, Blocking severity — and could not be summarised here.)
Conclusion and Next Steps
Decision: Proceed with Guardrails
Rationale: The HOCM-specific evidence base is genuine and decades-deep (multiple RCTs and haemodynamic studies), giving L2 evidence strength and a clear, already-exploited mechanistic pathway. However, the safety data gap (DG001, Blocking) and absent MOA documentation (DG002) mean this cannot yet clear a full safety review, and the evidence is markedly weaker for cardiomyopathy subtypes outside HOCM (dilated, cirrhotic).
To proceed, the following is needed:
- SmPC/BNF-sourced warnings, contraindications and DDI data (resolves DG001, currently Blocking)
- Formal MOA documentation from DrugBank or equivalent (resolves DG002)
- Confirmation of current UK marketing authorisation status and licensed indications for propranolol
- Scoping restricted specifically to HOCM rather than cardiomyopathy broadly, given the mixed/negative signals for dilated and cirrhotic subtypes
- No further action on the three TxGNN-flagged candidates with no evidence (distal myopathy Tateyama type, congenital myopathy with thin filaments, chondroma) — these remain correctly at “Hold”
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.