Haloperidol

證據等級: L5

預測適應症: 10 個

Haloperidol: From Schizophrenia/Acute Psychosis to Manic Bipolar Affective Disorder

One-Sentence Summary

Haloperidol is a first-generation (typical) antipsychotic well established in the treatment of schizophrenia and acute psychotic states, acting primarily through potent dopamine D2 receptor antagonism in the mesolimbic pathway. The TxGNN model predicts it may be effective for Manic Bipolar Affective Disorder — the highest-evidence prediction in this Evidence Pack (ranked #10 by TxGNN score, but #1 by clinical evidence strength) — with 9 clinical trials and 20 publications currently supporting this direction.

Quick Overview

Item	Content
Original Indication	Schizophrenia, acute psychosis (no Singapore registration on file; based on established pharmacological class)
Predicted New Indication	Manic Bipolar Affective Disorder
TxGNN Prediction Score	99.83%
Evidence Level	L1
Singapore Market Status	Not marketed
Number of Registrations	0
Recommended Decision	Proceed with Guardrails

Why is This Prediction Reasonable?

Formal mechanism of action data from DrugBank was not available in this Evidence Pack. However, based on well-established pharmacology, Haloperidol is a butyrophenone-class typical antipsychotic that exerts its primary effect through potent dopamine D2 receptor antagonism (Ki ≈ 1 nM) in the mesolimbic pathway. Additional receptor-binding activities — including D1, α1-adrenergic, and H1 histamine antagonism — contribute to its rapid sedative and antimanic properties.

The mechanistic link to bipolar mania is both direct and well-supported. Acute manic episodes are characterised by hyperdopaminergic activity in the mesolimbic system, which is precisely the neurochemical substrate that D2 antagonism suppresses. This explains Haloperidol's notably rapid clinical onset in acute mania, with observable symptom reduction typically within 24–48 hours of initiation — a profile that distinguishes it from mood stabilisers such as lithium or valproate.

Schizophrenia and bipolar disorder share overlapping neurobiology, particularly dopamine dysregulation and the emergence of psychotic features. This mechanistic similarity makes the extension from one indication to the other pharmacologically coherent rather than coincidental. In fact, multiple international psychiatric guidelines (CANMAT, BAP, WFSBP) already recognise Haloperidol as a treatment option for acute mania, and the drug's consistent role as an active comparator in multiple large Phase 3 RCTs provides strong external validation for the TxGNN prediction.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrollment	Key Findings
NCT00097266	Phase 3	Completed	615	Head-to-head Aripiprazole vs Haloperidol monotherapy in acutely manic Bipolar I patients over 12 weeks; largest trial providing direct efficacy and tolerability data for Haloperidol in this indication
NCT00253162	Phase 3	Completed	439	Risperidone vs Placebo vs Haloperidol (active comparator) in Bipolar I manic episodes at 3 and 12 weeks; confirms Haloperidol as a gold-standard reference treatment
NCT00129220	Phase 3	Completed	224	Three-arm RCT: Olanzapine vs Placebo vs Haloperidol in manic or mixed Bipolar I episodes; provides direct head-to-head efficacy comparison
NCT00253149	Phase 3	Completed	158	Risperidone vs Placebo vs Haloperidol as add-on therapy to mood stabilisers in bipolar mania; supports Haloperidol's standard role in adjunctive treatment strategies
NCT00126009	Phase 2	Completed	120	Open randomised trial comparing Valproate + Amisulpride vs Valproate + Haloperidol over 3 months in Bipolar I mania; evaluates combination therapy and safety profile
NCT04327843	Phase 3	Completed	22	Long-acting injectable antipsychotics (including Haloperidol decanoate) combined with behavioural programme in chronic psychotic/manic disorders in Tanzania; limited by very small sample size and resource-limited setting
NCT03541031	N/A	Unknown	120	Micronutrient supplement adjunctive treatment for bipolar disorder; Haloperidol likely serves as background standard-of-care medication rather than primary intervention
NCT00767715	Phase 4	Terminated	11	Olanzapine vs conventional antipsychotics (including Haloperidol) in acute mania in Sweden; terminated prematurely with insufficient data for conclusions
NCT06049953	N/A	Recruiting	200	Observational study of antenatal antipsychotic exposure (including Haloperidol) and infant developmental outcomes through 2027; focuses on safety rather than antimanic efficacy

Literature Evidence

PMID	Year	Type	Journal	Key Findings
34642461	2022	Systematic Review + Network Meta-Analysis	Molecular Psychiatry	Comprehensive NMA across all double-blind RCTs for acute bipolar mania pharmacotherapy; establishes Haloperidol's efficacy ranking relative to atypical antipsychotics and mood stabilisers
22134043	2012	RCT	Journal of Affective Disorders	Double-blind, placebo- and Haloperidol-controlled trial in Japanese Bipolar I patients with manic/mixed episodes; relevant for Asian population (including Singapore context)
36789916	2023	Systematic Review	BMJ Mental Health	Antipsychotic dose equivalence comparison between acute mania and schizophrenia; confirms Haloperidol dosing benchmarks for bipolar mania and cross-indication dose calibration
33460070	2020	Clinical Practice Review	Acta Psychiatrica Scandinavica	Evidence-based treatment algorithm for bipolar mania including Haloperidol, with clinical decision guidance on mood stabiliser and antipsychotic selection
22070611	2012	Review	CNS Neuroscience & Therapeutics	Refractory bipolar disorder management; Haloperidol explicitly recommended as add-on strategy in patients with partial response to lithium, valproate, or carbamazepine
18344731	2008	Systematic Review	Journal of Clinical Psychopharmacology	Comparative EPS risk of antipsychotics in bipolar disorder vs schizophrenia; documents Haloperidol's higher EPS incidence vs atypicals, critical for risk-benefit assessment
39756485	2025	Retrospective Analysis	Journal of Affective Disorders	Real-world effectiveness of long-acting injectable antipsychotics (including Haloperidol decanoate) during manic episodes; evaluates impact on rehospitalisation rates
3312180	1987	RCT	Journal of Clinical Psychiatry	Early double-blind controlled trial comparing Clonazepam vs Lithium vs Haloperidol in acute mania; foundational evidence establishing Haloperidol's antimanic efficacy
22161387	2011	Cochrane Systematic Review	Cochrane Database of Systematic Reviews	Oxcarbazepine vs standard treatments (including Haloperidol-containing arms) for bipolar episodes; contextualises Haloperidol as established comparator in controlled trial methodology
369472	1979	RCT	Archives of General Psychiatry	Double-blind 5-week controlled trial of Lithium carbonate + Haloperidol vs Placebo + Haloperidol in excited schizo-affective patients; early RCT evidence for Haloperidol combination use in affective psychosis

Singapore Market Information

Haloperidol is currently not registered in Singapore. No product authorisations are on file (total licences: 0).

Note: Haloperidol is broadly approved in major regulatory jurisdictions outside Singapore, including the US FDA (schizophrenia, Tourette's syndrome), EMA, and TGA (Australia). It is also included on the WHO Model List of Essential Medicines. The absence of a Singapore registration does not reflect lack of clinical utility — it may warrant a registration application or compassionate use pathway should clinical adoption be pursued.

Safety Considerations

Formal safety data (package insert warnings, contraindications, and drug interaction records) were not available in this Evidence Pack. Please refer to the package insert for full safety information.

Based on published literature and the drug's pharmacological class, the following safety signals are particularly relevant in the context of bipolar mania:

Extrapyramidal Symptoms (EPS): Haloperidol carries a high risk of akathisia, parkinsonism, acute dystonia, and long-term tardive dyskinesia — significantly higher than atypical antipsychotics. This is a key consideration when selecting antipsychotics for bipolar patients who require functional recovery.
QTc Prolongation: Haloperidol can prolong the cardiac QT interval, with risk of torsades de pointes at higher doses or in combination with other QTc-prolonging agents. Baseline and on-treatment ECG monitoring is recommended.
Neuroleptic Malignant Syndrome (NMS): Rare but potentially fatal; requires immediate discontinuation and supportive management.
Antenatal exposure risks: As noted in NCT06049953, Haloperidol use during pregnancy warrants careful risk-benefit assessment.

Conclusion and Next Steps

Decision: Proceed with Guardrails

Rationale: Haloperidol has robust Level 1 clinical evidence (≥2 completed Phase 3 RCTs) supporting its use in acute bipolar mania, with a well-characterised mechanistic basis in dopamine D2 antagonism that directly addresses hyperdopaminergic mania pathophysiology. Its efficacy as both a direct treatment agent and as a gold-standard active comparator in multiple large trials is well documented. The primary concern is not efficacy but tolerability — particularly EPS risk — and the absence of a current Singapore market registration.

To proceed, the following is needed:

Regulatory pathway: Determine Singapore registration strategy for the bipolar mania indication (new NDA submission, indication extension, or formulary/hospital listing under existing compassionate use provisions)
Formal MOA documentation: Retrieve full package insert and DrugBank MOA data (DrugBank DB00502) to satisfy DG002 data gap
Safety assessment completion: Obtain TFDA/HSA-equivalent package insert warnings and contraindications (DG001 — currently Blocking severity)
Risk mitigation plan: Develop EPS monitoring protocol and patient selection criteria to differentiate use cases where Haloperidol is preferred over atypical antipsychotics (e.g., acute severe mania with psychosis requiring rapid parenteral control)
Drug interaction review: Conduct formal DDI screening, particularly for QTc-prolonging co-medications commonly used in bipolar disorder (e.g., lithium, some antidepressants)
Asian population data review: Review efficacy and safety data in East/Southeast Asian populations (e.g., PMID 22134043 Japanese RCT) to assess any pharmacogenomic or dosing considerations relevant to Singapore patients
Disclaimer

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