Ziprasidone
| Evidence Level: L2 | Predicted Indications: 10 |
Table of Contents
Ziprasidone: From Bipolar Mania to Major Affective Disorder
One-Sentence Summary
Ziprasidone is a second-generation antipsychotic with an established role in schizophrenia and bipolar I disorder (manic/mixed episodes). Evidence assembled in this pack indicates a further, evidence-backed signal for Major Affective Disorder — specifically as adjunctive therapy in bipolar depression and treatment-resistant major depressive disorder (MDD) — supported by 27 clinical trials (several completed Phase 3 RCTs) and 20 publications, including RCTs and meta-analyses.
Note on candidate selection: TxGNN’s single highest-scoring hit (trichotillomania, score 99.83%) and several other top raw-score predictions (hydranencephaly, congenital disorder of glycosylation, X-linked myopia variants, a retinal dystrophy, polymicrogyria syndrome) have no supporting clinical trials or literature and are explicitly assessed in the evidence pack as knowledge-graph embedding noise with no plausible mechanistic link. This report therefore focuses on major affective disorder, the candidate with the strongest evidence base (L2, “Proceed with Guardrails”), rather than the raw top-ranked score.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not formally recorded in this evidence pack (regulatory licence data and DrugBank indication field are both empty). Trial-level context confirms ziprasidone’s established approved use is schizophrenia and bipolar I disorder (manic or mixed episodes). |
| Predicted New Indication | Major Affective Disorder (bipolar depression / adjunctive treatment of treatment-resistant MDD) |
| TxGNN Prediction Score | 99.66% |
| Evidence Level | L2 |
| UK Market Status | Not marketed |
| Number of Marketing Authorisations | 0 |
| Recommended Decision | Proceed with Guardrails |
Why is This Prediction Reasonable?
Detailed mechanism-of-action data is not separately recorded in the regulatory dataset (DrugBank MOA field is flagged as a data gap, DG002). However, the clinical evidence review characterises ziprasidone’s core pharmacology as antagonism at dopamine D2/D3 and serotonin 5-HT2A receptors, partial agonism at 5-HT1A, and moderate inhibition of serotonin/noradrenaline reuptake — a receptor profile shared with other second-generation antipsychotics (quetiapine, aripiprazole, olanzapine) that are already licensed as antidepressant adjuncts.
Bipolar mania/mixed episodes are already an approved indication for ziprasidone, and bipolar depression and MDD sit within the same affective-disorder spectrum. Extending use into the depressive pole of bipolar illness, and into antidepressant augmentation for treatment-resistant unipolar MDD, is therefore a mechanistically coherent and clinically well-precedented extension rather than a novel therapeutic hypothesis.
The 5-HT2A antagonism and 5-HT1A partial agonism are the pharmacological features most commonly invoked to explain the antidepressant-augmenting effect of atypical antipsychotics, while D2 antagonism underlies the antimanic effect already recognised in ziprasidone’s label. The main caution is ziprasidone’s known QT-interval prolongation liability, which several of the identified RCTs specifically monitored (see Safety Considerations).
Clinical Trial Evidence
| Trial Number | Phase | Status | Enrolment | Key Findings |
|---|---|---|---|---|
| NCT00483548 | Phase 3 | Completed | 298 | Double-blind, placebo-controlled RCT of ziprasidone as add-on to lithium, valproate or lamotrigine in bipolar I depression. |
| NCT00141271 | Phase 3 | Completed | 536 | 6-week fixed/flexible-dose RCT of oral ziprasidone monotherapy vs placebo in outpatients with bipolar I depression. |
| NCT00282464 | Phase 3 | Completed | 392 | Companion 6-week RCT of flexible-dose oral ziprasidone monotherapy vs placebo in bipolar I depression outpatients. |
| NCT00107939 | Phase 3 | Completed | 453 | Multicentre placebo-controlled RCT of adjunctive therapy in manic episodes, with ziprasidone among the atypical antipsychotic base regimens studied. |
| NCT00312494 | Phase 3 | Completed | 680 | 3-week RCT of add-on oral ziprasidone with lithium or divalproex vs placebo in acute mania. |
| NCT00555997 | Phase 2 | Completed | 120 | 12-week randomised, placebo-controlled, parallel-sequential trial of ziprasidone monotherapy for major depressive disorder. |
| NCT00633399 | Phase 2 | Completed | 458 | Three-phase RCT testing ziprasidone augmentation of SSRIs in patients with SSRI-non-responsive MDD. |
| NCT02075047 | Phase 3 | Terminated | 171 | Randomised, double-blind, placebo-controlled trial of flexible-dose oral ziprasidone in paediatric bipolar I mania; stopped early. |
| NCT00667745 | Phase 4 | Completed | 283 | Pragmatic effectiveness trial (LiTMUS) of lithium as adjunct in bipolar disorder, with ziprasidone available as one optimised-treatment option. |
| NCT01053429 | N/A | Completed | 3391 | Large regulatory post-marketing pharmacovigilance study of ziprasidone (Zeldox) capsules across the 20–80 mg dose range in real-world patients. |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 26085041 | 2015 | RCT | The American Journal of Psychiatry | Adjunctive ziprasidone added to escitalopram significantly improved depressive symptoms vs placebo in SSRI-non-responsive MDD. |
| 27835715 | 2017 | RCT | The Journal of Clinical Psychiatry | Companion RCT reporting cardiac (QTc), endocrine, metabolic and motoric safety outcomes of adjunctive ziprasidone in MDD. |
| 24815673 | 2014 | RCT | International Clinical Psychopharmacology | 12-week sequential parallel comparison trial evaluating ziprasidone monotherapy in MDD with/without psychomotor symptoms. |
| 28749091 | 2018 | RCT (secondary analysis) | The Journal of Clinical Psychiatry | Analysis of the escitalopram-augmentation RCT series showing benefit of adjunctive ziprasidone on cognitive symptoms of MDD. |
| 34986373 | 2022 | Network Meta-analysis | Journal of Affective Disorders | Compares augmentation agents (including second-generation antipsychotics) for treatment-resistant depression. |
| 35510505 | 2023 | Systematic Review/Meta-analysis | Psychological Medicine | Efficacy and safety/tolerability of antipsychotics (monotherapy and adjunctive) in adult MDD. |
| 35993319 | 2022 | Systematic Review/Network Meta-analysis | Psychological Medicine | Efficacy and acceptability of second-generation antipsychotics combined with antidepressants for unipolar depression augmentation. |
| 34238049 | 2021 | Review | Journal of Psychopharmacology | Compares antidepressant + second-generation antipsychotic combinations vs esketamine vs lithium for MDD. |
| 19040553 | 2008 | Review | CNS Neuroscience & Therapeutics | Narrative review of ziprasidone’s role across affective disorders (bipolar mania, mixed episodes, depression) and its distinctive receptor profile. |
| 22999893 | 2013 | Review/Analysis | Journal of Affective Disorders | Reviews adjunctive ziprasidone (with lithium or valproate) for relapse prevention in bipolar disorder. |
UK Market Information
No marketing authorisations are currently recorded for ziprasidone in this evidence pack (0 licences; market status: Not marketed). This is flagged in the underlying data gap log (DG001) as a blocking issue for formal safety assessment, since UK product labelling could not be retrieved or parsed.
Safety Considerations
Formal safety fields (key warnings, contraindications, drug–drug interactions) are not populated in this evidence pack and could not be independently sourced. However, the clinical evidence review itself flags an important safety signal:
- QT Interval Prolongation: Ziprasidone carries a recognised cardiac safety liability. This was specifically monitored in the escitalopram-augmentation RCT (PMID 27835715), and a case of sudden death during a paediatric ziprasidone trial has been reported elsewhere in the wider evidence base (PMID 15728441). ECG monitoring is a reasonable guardrail for any repurposing pathway involving affective disorders.
Please refer to the SmPC and BNF for complete safety information. Report suspected adverse reactions via the Yellow Card Scheme.
Conclusion and Next Steps
Decision: Proceed with Guardrails
Rationale: Multiple completed Phase 2/3 RCTs (e.g. NCT00483548, NCT00141271, NCT00555997, NCT00633399), together with systematic reviews and network meta-analyses, provide a consistent efficacy signal for ziprasidone in bipolar depression and as an antidepressant-augmentation agent in treatment-resistant MDD. This is mechanistically coherent with its existing approved use in bipolar mania. However, the absence of formal UK licensing data and product-label safety information, combined with a known QT-prolongation liability, means this cannot proceed without additional safeguards.
To proceed, the following is needed:
- Resolve blocking data gap DG001: retrieve and parse the SmPC/regulatory label (warnings, contraindications) before any formal safety (S1) assessment.
- Resolve data gap DG002: obtain a confirmed DrugBank mechanism-of-action record to formally verify the receptor-binding profile currently inferred only from trial rationale text.
- Confirm UK marketing-authorisation/licensing status, since zero licences are currently on record for this drug.
- Establish a cardiac monitoring protocol (baseline and follow-up ECG) given the identified QT-prolongation signal.
- Tourette syndrome (L3, “Research Question”, supported mainly by small pilot studies and case reports, with one reported sudden death during a paediatric trial) may warrant a dedicated, appropriately monitored pilot RCT, but is a lower-priority secondary signal relative to the affective-disorder candidate.
- The remaining top raw-score TxGNN predictions (trichotillomania, hydranencephaly, congenital disorder of glycosylation, X-linked myopia subtypes, retinal dystrophy with extraocular anomalies, polymicrogyria syndrome) have no supporting trial or literature evidence and should remain on Hold.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.