Felodipine

證據等級: L5

預測適應症: 7 個

Felodipine: From Hypertension to Pulmonary Hypertension (Multifactorial Mechanism)

One-Sentence Summary

Felodipine is a dihydropyridine calcium channel blocker (DHP-CCB) used internationally for essential hypertension and stable angina, though it is currently not registered or marketed in the Netherlands. The TxGNN model ranks pulmonary hypertension with unclear multifactorial mechanism as its top predicted new indication with a score of 99.91%, however no supporting clinical trials or literature exist for this specific direction — this remains a model-only signal (L5) with documented safety concerns for broad patient populations.

Quick Overview

Item	Content
Original Indication	Not registered in the Netherlands; internationally known for hypertension and stable angina
Predicted New Indication	Pulmonary hypertension with unclear multifactorial mechanism
TxGNN Prediction Score	99.91%
Evidence Level	L5
NL Market Status	Not marketed
Number of Authorizations	0
Recommended Decision	Hold

All Predicted Indications — Summary

Rank	Indication	TxGNN Score	Evidence Level	Decision
1	Pulmonary hypertension (multifactorial mechanism)	99.91%	L5	Hold
2	Pulmonary hypertension (lung disease / hypoxia)	99.91%	L5	Hold
3	Malignant hypertensive renal disease	99.90%	L5	Hold
4	Malignant renovascular hypertension	99.90%	L5	Hold
5	Braddock syndrome	99.88%	L5	Hold
6	Chronic pulmonary heart disease	99.19%	L4	Research Question
7	Prinzmetal angina	99.07%	L2	Proceed with Guardrails

Key observation: Although Prinzmetal angina ranks 7th by TxGNN score, it carries the strongest clinical evidence (L2) and is the most immediately actionable repurposing candidate. See the dedicated section below.

Why is This Prediction Reasonable?

Currently, detailed mechanism of action data is not available from DrugBank for this candidate. Based on known pharmacology, Felodipine belongs to the dihydropyridine (DHP) subclass of calcium channel blockers (CCBs). It acts primarily by blocking L-type voltage-gated calcium channels in vascular smooth muscle, producing vasodilation and reducing systemic vascular resistance. This mechanism is established for hypertension management and coronary spasm prevention.

The connection between Felodipine and pulmonary hypertension has a historical basis: CCBs have been used in a select minority (<10%) of pulmonary arterial hypertension (PAH, WHO Group 1) patients who demonstrate a positive acute vasoreactivity test. In these responders, CCBs can significantly reduce pulmonary vascular resistance and improve functional class. This explains why the TxGNN model — which operates over a broad pharmacological knowledge graph — identifies a mechanistic link.

However, the predicted indication specifically involves “multifactorial mechanism” pulmonary hypertension, where the underlying pathophysiology is heterogeneous and poorly characterised. In the large majority of PAH patients who are non-responders to vasoreactivity testing, CCBs can worsen prognosis by dropping systemic blood pressure without adequately relieving pulmonary vascular resistance, potentially increasing right heart strain and mortality. Current EMA-aligned clinical guidelines explicitly caution against CCB use in non-vasoreactive PAH. This signal should be treated as a mechanistic hypothesis only and requires substantial preclinical and clinical validation before any progression.

Clinical Trial Evidence

Currently no related clinical trials registered.

Literature Evidence

Currently no related literature available.

Netherlands Market Information

Felodipine is not registered or marketed in the Netherlands. No CBG-MEB marketing authorisations (RVG numbers) have been issued for any Felodipine product. Any clinical use in the Netherlands would require either:

An off-label use framework under Dutch pharmaceutical law, or
A new marketing authorisation application to CBG-MEB (or centralised EMA procedure)

For comparator context: related DHP-CCBs (e.g., Amlodipine, Nifedipine) are registered in the Netherlands and their SmPCs can serve as a safety benchmarking reference for regulatory discussions.

Safety Considerations

Please refer to the SmPC (Summary of Product Characteristics) for complete safety information.

As a class-level note: DHP calcium channel blockers carry known risks of peripheral vasodilation-related adverse effects (flushing, peripheral oedema, reflex tachycardia) and clinically significant interactions with CYP3A4 inhibitors (including grapefruit juice, azole antifungals, and certain HIV protease inhibitors). For any pulmonary hypertension application specifically, the risk of systemic hypotension and worsening of ventilation-perfusion mismatch requires careful patient selection and haemodynamic monitoring. Formal SmPC documentation must be obtained before any clinical application in the Netherlands.

Notable Finding: Prinzmetal Angina (Rank 7 — Strongest Evidence)

Although TxGNN ranks this indication 7th, Prinzmetal angina (vasospastic angina) is the single most clinically evidenced repurposing opportunity for Felodipine in this evaluation. It carries an evidence level of L2 and a “Proceed with Guardrails” recommendation.

Why the mechanism fits: Prinzmetal angina is caused by spontaneous spasm of coronary artery smooth muscle, producing transient ST-segment elevation. DHP-CCBs block L-type calcium channels directly in coronary smooth muscle, preventing vasospasm. Felodipine shares this mechanism with Nifedipine, which is already approved for this indication in multiple countries. Multiple controlled studies from 1989–1995 directly evaluated Felodipine in this setting.

Literature Evidence — Prinzmetal Angina

PMID	Year	Type	Journal	Key Findings
1746458	1991	RCT (active-controlled)	Am J Cardiology	Felodipine 10–20 mg once daily vs. Nifedipine 20 mg four times daily in 30 Prinzmetal patients; comparable anti-ischaemic efficacy confirmed by 24-hour Holter monitoring
8013514	1994	Controlled Trial (ergonovine challenge)	Eur Heart J	Extended-release Felodipine 20 mg once daily significantly suppressed ergonovine-induced myocardial ischaemia in 14 patients at both 4 h and 24 h post-dose
2909138	1989	Controlled Trial (hyperventilation challenge)	Am J Cardiology	Felodipine reduced hyperventilation-induced ischaemic ST changes in variant angina patients
7744087	1995	RCT (double-blind, 3-way crossover)	Eur Heart J	Felodipine ER 10 mg vs. Nifedipine SR 20 mg vs. placebo in 43 stable angina patients; Felodipine improved exercise duration by 66 seconds (p < 0.05) at end of dosing interval
7728649	1995	Review (Felodipine-focused)	Can J Cardiology	Comprehensive review of Felodipine across angina syndromes; confirms CCBs as first-line for Prinzmetal angina via anti-vasospastic mechanism
14689111	2003	Review	Herz	Differential CCB therapy across cardiovascular indications; supports DHP-CCBs for vasospastic angina
3345765	1988	Case Series	Eur Heart J	Exercise-induced intermittent ST elevation in Prinzmetal angina documented; illustrates clinical presentation spectrum
19052677	2008	Case Report	Can J Cardiology	Vasospasm-induced polymorphic ventricular tachycardia; highlights severity of untreated coronary spasm
15222138	2004	Case Report	Orvosi Hetilap	Nicergoline-induced Prinzmetal angina in a hypertensive patient; reinforces vasospasm aetiology recognition

Conclusion and Next Steps

Top Prediction (Rank 1 — Pulmonary Hypertension, Multifactorial)

Decision: Hold

Rationale: The top TxGNN prediction lacks any supporting clinical trials or literature, and the underlying indication encompasses a heterogeneous patient population in whom CCBs have documented potential for harm. This signal does not meet the threshold for further development at this stage.

To re-evaluate this prediction in the future:

Obtain a positive acute vasoreactivity test result profile for the specific patient subgroup of interest
Identify mechanistic research establishing CCB efficacy in the multifactorial PH subtype
Review WHO/ESC pulmonary hypertension guidelines for updated CCB positioning

Prinzmetal Angina (Rank 7 — Most Actionable Candidate)

Decision: Proceed with Guardrails

Rationale: Multiple controlled trials (including double-blind RCTs and provocation challenge studies) conducted between 1989 and 1995 directly confirm Felodipine’s efficacy in Prinzmetal angina. The mechanism is shared with Nifedipine, which is already approved for this indication. This constitutes the strongest repurposing signal in this evaluation.

To proceed, the following is needed:

Retrieve complete MOA documentation from DrugBank (currently absent) to complete mechanistic dossier
Obtain full SmPC from a comparable registered DHP-CCB (e.g., Nifedipine) for cross-reference safety benchmarking
Consult CBG-MEB on the appropriate regulatory pathway: off-label use guidance vs. new marketing authorisation application for Felodipine in the Netherlands
Conduct a systematic literature update (2000–present) to capture any post-1995 Felodipine data in vasospastic angina
Prepare a pharmacovigilance plan before any clinical introduction

Summary of All Predictions

Rank	Indication	Decision	Priority
1	Pulmonary hypertension (multifactorial)	Hold	Low
2	Pulmonary hypertension (lung disease/hypoxia)	Hold	Low
3	Malignant hypertensive renal disease	Hold	Low
4	Malignant renovascular hypertension	Hold	Low
5	Braddock syndrome	Hold	Very Low
6	Chronic pulmonary heart disease	Research Question	Medium (basic research)
7	Prinzmetal angina	Proceed with Guardrails	High

Disclaimer: This report is produced for research purposes only and does not constitute medical advice. All repurposing candidates require clinical validation before therapeutic application. Content is intended to support regulatory and research discussions within the Netherlands healthcare system under CBG-MEB oversight.

Disclaimer

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