Pimozide
| Evidence Level: L3 | Predicted Indications: 10 |
Table of Contents
Pimozide: From Tourette Syndrome to Trichotillomania
One-Sentence Summary
Pimozide is a dopamine D2-blocking antipsychotic, originally used as a backup treatment for Tourette syndrome. The TxGNN model predicts it may be effective for trichotillomania (a hair-pulling disorder), but no clinical trials are registered and only 8 publications (mostly reviews and one small, dated clinical study) touch on this direction.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Tourette syndrome |
| Predicted New Indication | Trichotillomania |
| TxGNN Prediction Score | 99.996% |
| Evidence Level | L3 |
| US Market Status | Cancelled only (the single ANDA is cancelled) |
| Number of NDAs | 1 (ANDA) |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism of action data is not available in the data compiled for this report. Pimozide is known as a dopamine D2 receptor antagonist of the diphenylbutylpiperidine class, and its efficacy in Tourette syndrome has been established.
Tourette syndrome, obsessive-compulsive disorder and trichotillomania share overlapping phenomenology and treatment response, and are all characterized by repetitive, habitual behaviors. Dopaminergic hyperactivity is implicated in such behaviors, so D2 blockade may plausibly help. A 1992 study examined low-dose pimozide added to serotonin reuptake inhibitors in trichotillomania (PMID 1532960). The supporting evidence is small and dated, so it should be read as limited clinical data rather than proof of efficacy.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 1532960 | 1992 | Clinical study (small) | J Clin Psychiatry | Low-dose pimozide augmentation of serotonin reuptake blockers in trichotillomania; notes overlap with Tourette syndrome and OCD |
| 15554735 | 2004 | Review | Am J Clin Dermatol | Comprehensive review of pimozide in dermatologic practice; in the US it is FDA-approved only for Tourette syndrome, other uses are off-label |
| 30446201 | 2018 | Review | Clin Dermatol | Antipsychotics in dermatology; D2 blockade plus other receptor effects can be useful |
| 36802832 | 2023 | Evidence mapping/Review | J Cutan Med Surg | Maps randomized trial evidence for drug treatment of primary psychodermatologic disorders |
| 27320510 | 2016 | Review | Tijdschr Psychiatr | Treatment options for paediatric trichotillomania; pharmacological research is limited |
| 10497682 | 1999 | Review | Ann Acad Med Singapore | Overview of trichotillomania as an under-diagnosed chronic psychiatric condition |
| 10357517 | 1999 | Case series | J Child Adolesc Psychopharmacol | Risperidone (not pimozide) added in three SRI-resistant cases; all improved. Notes earlier benefit of pimozide |
| 11475941 | 2001 | Review | CNS Drugs | Psychogenic excoriation (indirect relevance) |
US Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| ANDA204521 (cancelled) | Pimozide (Endo USA, Inc.) | Tablet (oral) | Not listed |
Safety Considerations
No package insert warnings or contraindications were available in the data compiled for this report; please refer to the package insert for label safety information.
- Contraindications (from knowledge-graph drug–disease edges, not label text): long QT syndrome (including familial), torsades de pointes, sudden cardiac arrest, heart conduction disease, epilepsy, kidney disease, liver disease, gallbladder disease, potassium deficiency, benign prostatic hyperplasia, glaucoma, neuroleptic malignant syndrome, Alzheimer disease, female breast carcinoma, and neutropenia-related conditions (neutropenia, agranulocytosis, leukopenia, and several congenital neutropenia syndromes).
- Drug Interactions: 100 interactions were recorded. Major-level examples among those reviewed include hydrocortisone, amphotericin B, bupropion, aprepitant, morphine, lorcaserin, cimetidine, potassium citrate, clarithromycin, picosulfuric acid and polyethylene glycol with electrolytes. Moderate-level examples include famotidine, epinephrine, hyoscyamine, loperamide, atropine, bisacodyl, glycopyrronium and dicyclomine. A published case report also describes a paroxetine–pimozide interaction (PMID 7961347).
- The QT-prolongation and cardiac risk is a central concern for any new use.
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction is mechanistically plausible, but the only direct evidence is one small 1992 study and general reviews, with no registered trials. The US product is cancelled, and pimozide carries significant QT-related cardiac risk and a heavy interaction burden.
To proceed, the following is needed:
- Mechanism of action data and FDA package insert warnings and contraindications (currently missing; the missing label safety data is a blocking gap for safety screening)
- Modern controlled evidence of pimozide in trichotillomania, compared with established treatments
- A cardiac safety plan (ECG and QT monitoring, electrolyte control) and an interaction management strategy
- Confirmation of a currently available US product, since the only listed authorization is cancelled
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.