Chlorpromazine

Evidence Level: L5

Predicted Indications: 9

Chlorpromazine

Pharmacist Assessment Report

Chlorpromazine: phenothiazine antipsychotic (dopamine D2 and multi-receptor antagonist) → retinal dystrophy with or without extraocular anomalies

One-Sentence Summary

Chlorpromazine is a phenothiazine antipsychotic that is registered in Australia as an injectable product. The TxGNN model predicts it may be effective for retinal dystrophy with or without extraocular anomalies, but no clinical trials and only 1 publication are available, and that publication reports a safety concern (phototoxic reactions) rather than a benefit.

Quick Overview

Item	Content
Original Indication	Not recorded in the local data
Predicted New Indication	retinal dystrophy with or without extraocular anomalies
TxGNN Prediction Score	0.9995
Evidence Level	L5
Australia Market Status	Listed on the PBS Schedule (1 of 1 items) – TGA (ARTG) registration status is not included in this data
Number of PBS Items	1 (valid: 1)
Recommended Decision	Hold

Why is This Prediction Reasonable?

Detailed mechanism of action data is not available in the data compiled for this report. Chlorpromazine is generally described as a dopamine D2 and multi-receptor antagonist.

The data compiled for this report do not support a therapeutic mechanism for this prediction. The only publication (1967) describes phototoxic reactions after high doses of chlorpromazine and thioridazine, which is an adverse effect, not evidence of benefit. Chlorpromazine is also known to cause pigmentary deposits in the retina and cornea at high doses, so it could worsen an existing retinal dystrophy. The high TxGNN score appears to reflect a computational association with the eye rather than a treatment rationale.

Clinical Trial Evidence

Currently no related clinical trials registered.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
5336672	1967	Review / case observation	JAMA	Phototoxic reactions induced by high doses of chlorpromazine and thioridazine; a safety signal, not evidence of benefit for retinal dystrophy

Australia Market Information

ARTG Number	Product Name	Dosage Form	Approved Indication
ARTG 1195X	Largactil	Injection containing chlorpromazine hydrochloride 50 mg in 2 mL	Not recorded in the local data

Safety Considerations

Safety information for this product was not available in the data compiled for this report. Please refer to the TGA-approved Product Information (PI) for warnings and contraindications.

Drug Interactions (100 interactions recorded; selected examples):

Major: bupropion, morphine
Moderate: acarbose, famotidine, epinephrine, hydrocortisone, metformin, pioglitazone, amphotericin B, hyoscyamine, loperamide, atropine, glycopyrronium, canagliflozin, chlorpropamide

Of note, the pattern of moderate interactions includes glucose-lowering agents and anticholinergic agents, which warrants clinical review before any co-prescription.

Conclusion and Next Steps

Decision: Hold

Rationale: No clinical trials support this prediction. The only publication reports a phototoxic adverse effect, and chlorpromazine’s known retinal pigmentary effects point to potential harm in retinal disease. The evidence level is L5 because no cited study addresses the predicted disease as a treatment.

To proceed, the following is needed:

Any preclinical or clinical evidence showing a therapeutic effect in inherited retinal dystrophy
Detailed mechanism of action data and a plausible mechanistic link to retinal degeneration
A review of ocular safety, including retinal and corneal pigmentary changes and phototoxicity
Warnings and contraindications from the TGA-approved Product Information
Disclaimer

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