Amlodipine

證據等級: L5

預測適應症: 10 個

Amlodipine: From Hypertension to Intracerebral Hemorrhage Secondary Prevention

One-Sentence Summary

Amlodipine is a dihydropyridine calcium channel blocker (CCB) widely used for hypertension and stable angina worldwide. The TxGNN model identifies 10 neurological and vascular repurposing candidates; intracerebral hemorrhage (ICH) secondary prevention shows the strongest clinical evidence among them, with 5 clinical trials (including a completed Phase 3 RCT) and 8 publications identified. The recommended decision for this lead indication is Proceed with Guardrails.

Quick Overview

Item	Content
Original Indication	Hypertension; Chronic stable angina; Vasospastic angina
Primary Actionable Prediction	Intracerebral Hemorrhage (Secondary Prevention)
TxGNN Prediction Score	99.79% (intracerebral hemorrhage) / 99.94% (top-ranked: brain stem infarction)
Evidence Level	L2 — Intracerebral Hemorrhage (lead candidate); L5 for 7 of 10 predictions
Singapore Market Status	✗ Not marketed
Number of Registrations	0
Recommended Decision	Proceed with Guardrails (ICH); Hold for 7 of 10 predictions

All Predicted Indications at a Glance

TxGNN Rank	Disease	TxGNN Score	Evidence Level	Decision
1	Brain Stem Infarction	99.94%	L5	Hold
2	Pulmonary Hypertension (Lung Disease/Hypoxia)	99.91%	L5	⚠️ Hold — Safety concern
3	Pulmonary Hypertension (Multifactorial)	99.91%	L5	⚠️ Hold — Safety concern
4	Malignant Renovascular Hypertension	99.90%	L4	Research Question
5	Malignant Hypertensive Renal Disease	99.90%	L5	Hold
6	Cerebral Artery Occlusion	99.89%	L3	Research Question
7	Braddock Syndrome	99.88%	L5	Hold
8	MRI-Defined Brain Infarct	99.86%	L4	Hold
9	ABri Amyloidosis	99.84%	L5	Hold
10	Intracerebral Hemorrhage	99.79%	L2	★ Proceed with Guardrails

Note: TxGNN prediction score does not correlate with clinical evidence strength. Intracerebral hemorrhage ranks 10th by TxGNN score but 1st by evidence level — making it the primary actionable candidate in this pack.

⚠️ Safety alert (Ranks 2 & 3): Amlodipine is relatively contraindicated in WHO Group 3 (lung disease/hypoxia) and Group 5 (multifactorial mechanism) pulmonary hypertension. Systemic vasodilation may worsen ventilation-perfusion mismatch and aggravate hypoxaemia. Literature hits for these indications are false positives — general hypoxia biology papers with no relevance to Amlodipine efficacy. These indications should not be pursued.

Why is This Prediction Reasonable?

Amlodipine selectively blocks L-type voltage-gated calcium channels in arterial smooth muscle cells, causing vasodilation, reducing peripheral vascular resistance, and lowering blood pressure. Unlike many antihypertensives, its high lipophilicity enables membrane penetration, which may also confer antioxidant effects observed in experimental models. Its half-life of approximately 35–50 hours provides stable, predictable blood pressure control with once-daily dosing — a practical advantage for long-term secondary prevention.

Hypertension is the single most important modifiable risk factor for intracerebral haemorrhage (ICH), accounting for over 70% of cases. After an initial ICH event, the risk of recurrence remains substantially elevated. Intensive blood pressure reduction (SBP < 130 mmHg) is the cornerstone of secondary prevention, and this creates a direct mechanistic bridge: Amlodipine's antihypertensive mechanism addresses the primary pathophysiological driver of ICH recurrence. The TRIDENT trial — a completed Phase 3 international RCT (n=1,671) — specifically tested a fixed-dose triple combination BP-lowering strategy (including a dihydropyridine CCB) to prevent recurrent stroke in post-ICH patients. The CASE-J trial further provides direct comparative data on Amlodipine (CCB arm) versus Candesartan (ARB) in high-risk Japanese hypertensive patients, with cardiovascular and cerebrovascular events as primary endpoints.

Beyond blood pressure control, multiple animal studies demonstrate that Amlodipine reduces neuronal injury after cerebral ischaemia by blocking calcium overload-mediated excitotoxicity and scavenging reactive oxygen species — mechanisms potentially relevant to both haemorrhagic and ischaemic brain injury contexts. This preclinical basis also supports the Research Question recommendation for cerebral artery occlusion (Rank 6, L3 evidence), where five consistent rodent middle cerebral artery occlusion studies confirm neuroprotective effects.

Clinical Trial Evidence (Intracerebral Hemorrhage — Lead Indication)

Trial Number	Phase	Status	Enrollment	Key Findings
NCT02699645	Phase 3	Completed	1,671	TRIDENT: Multicentre international double-blind RCT of fixed-dose triple-pill BP-lowering therapy (including CCB) vs. standard care in post-ICH patients; primary endpoint: time to first recurrent stroke
NCT00134160	Phase 4	Completed	1,000	CASE-J sub-study: High-dose ARB (Candesartan) monotherapy vs. ARB + CCB (Amlodipine) combination in elderly Japanese hypertensive patients at high cardiovascular risk; cardiovascular events as primary endpoint
NCT03264352	Phase 4	Recruiting	11,414	IPAD: Antihypertensive treatment in type 2 diabetes with high-normal BP; broad cardiovascular/cerebrovascular event prevention; not ICH-specific but relevant to BP strategy
NCT03785067	Phase 3	Terminated	1	TRIDENT Cognitive Sub-study: Effect of intensive BP lowering on cognitive decline post-ICH; terminated due to insufficient enrolment — no usable data
NCT03783754	Phase NA	Terminated	4	TRIDENT MRI Sub-study: Imaging biomarkers of BP lowering in post-ICH patients; terminated early — provides contextual background only

Literature Evidence (Intracerebral Hemorrhage — Lead Indication)

PMID	Year	Type	Journal	Key Findings
34994269	2022	RCT Design Paper	Int J Stroke	TRIDENT trial rationale and design: confirms CCB-containing triple-pill strategy as the intervention for ICH secondary prevention
14717341	2003	RCT Protocol	Hypertension Research	CASE-J trial design: Candesartan vs. Amlodipine in 1,000 high-risk Japanese hypertensive patients; cardiovascular event endpoints — direct comparative Amlodipine data
23053838	2013	Observational Study	Neurological Sciences	Atenolol in acute hypertensive ICH (n=138); comparative evaluation of antihypertensive agents on mortality, SIRS, and 3-month outcomes
17077518	2006	Pharmacological Study	Biol Pharm Bull	Benidipine (dihydropyridine CCB, same class as Amlodipine) improves cerebral blood flow autoregulation in spontaneously hypertensive rats; class-level mechanistic support
3154329	1988	Narrative Review	Cardiovasc Drugs Therapy	Calcium channel antagonist mechanisms in severe hypertension; rationale for CCBs targeting calcium overload in vascular smooth muscle
19299323	2009	Case Report	Ann Pharmacother	⚠️ Probable Amlodipine-induced angioedema in a patient with right thalamic haemorrhagic stroke — safety signal requiring monitoring in ICH population
26698202	2015	Case Report	BMJ Case Reports	PRES following rapid antihypertensive withdrawal (including Amlodipine) post-bariatric surgery in a patient with ICH history — highlights risks of abrupt discontinuation
37489780	2024	Case Report	Current Drug Safety	Tizanidine-induced hypotension in stroke patient on multiple antihypertensives; safety context for multi-drug BP regimens in neurological patients

Additional Evidence: Cerebral Artery Occlusion (Research Question, L3)

Five animal studies directly tested Amlodipine in rodent middle cerebral artery occlusion (tMCAO) models and consistently demonstrated neuroprotective effects. No human clinical trials have directly tested Amlodipine for this indication.

PMID	Year	Type	Journal	Key Findings
21538457	2011	Animal Study	J Neuroscience Research	Amlodipine ± atorvastatin in metabolic syndrome rats after 90-min tMCAO: reduced infarct size via anti-apoptotic and anti-autophagic mechanisms
20971084	2011	Animal Study	Brain Research	Amlodipine + atorvastatin synergistic neuroprotection after tMCAO in Zucker metabolic rats; combination superior to either agent alone
17904110	2007	Animal Study	Brain Research	CCBs with antioxidative properties (including Amlodipine) prevent neuronal damage in focal ischaemia in rats; antioxidant mechanism implicated
17070425	2006	Animal Study	Am J Hypertension	Amlodipine reduces stroke size after focal brain ischaemia in apolipoprotein E-deficient mice; L-type calcium channel blockade confirmed as mechanism
21276424	2011	Animal Study	Brain Research	Combined Amlodipine + atorvastatin protection against ischaemic stroke in Zucker rats: infarct volume reduction and immune cell infiltration data

Safety Considerations

Key safety signals identified from literature review:

Angioedema: PMID 19299323 documents probable Amlodipine-induced angioedema in a thalamic haemorrhagic stroke patient. While angioedema is more classically associated with ACE inhibitors, it has been reported with CCBs. Active monitoring is warranted in post-ICH patients.
Not for acute ICH blood pressure management: Amlodipine's oral route and slow onset make it unsuitable for the acute phase of ICH, where rapid and titratable BP control is required (intravenous agents such as labetalol or nicardipine are preferred acutely). Amlodipine's role is exclusively in chronic secondary prevention.
Pulmonary hypertension: Amlodipine is relatively contraindicated in WHO Group 3 and Group 5 pulmonary hypertension (Predictions 2 and 3 in this pack). Systemic vasodilation can worsen ventilation-perfusion mismatch. These two indications should not be pursued.
Drug interactions: No DDI data was retrieved in this evidence pack. Full drug interaction review is required before clinical use.

Full prescribing information (HSA-registered label or international equivalent such as FDA label or EMA SmPC) must be consulted for complete warnings, contraindications, and drug interactions prior to any clinical decision.

Conclusion and Next Steps

Decision: Proceed with Guardrails

Rationale: The TRIDENT Phase 3 RCT (n=1,671, completed) provides Level 2 evidence supporting CCB-inclusive intensive blood pressure-lowering therapy for ICH secondary prevention. Combined with CASE-J direct comparative data on Amlodipine in high-risk hypertensive patients with cerebrovascular endpoints, and a mechanistically coherent rationale (BP reduction targeting the primary driver of ICH recurrence), intracerebral haemorrhage secondary prevention is the most actionable repurposing candidate in this Evidence Pack.

To proceed, the following is needed:

Confirm TRIDENT final efficacy results and identify whether Amlodipine specifically was the CCB used in the fixed-dose triple combination
Obtain full Amlodipine prescribing information (via HSA or FDA/EMA label) to complete safety profiling (Key Warnings, Contraindications, DDI)
Assess HSA registration pathway and feasibility for Singapore market (currently 0 active registrations)
Conduct population-specific analysis for Asian/Singaporean ICH patient populations, including ethnicity-related pharmacokinetic considerations
Develop safety monitoring plan including: angioedema surveillance, guidance on acute vs. chronic-phase usage, and BP target protocol (SBP < 130 mmHg)
Evaluate cerebral artery occlusion as a secondary research question: 5 consistent animal studies (L3) demonstrate neuroprotection via calcium overload blockade and antioxidant mechanisms — a Phase 2 proof-of-concept human study would be the logical next step
Disclaimer

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