Diazepam

Evidence Level: L2

Predicted Indications: 10

Diazepam

Pharmacist Assessment Report

Diazepam: Insomnia (disease)

One-Sentence Summary

Diazepam is a long-established benzodiazepine that enhances inhibitory GABA-A receptor signalling. The TxGNN model predicts it may be useful for insomnia (disease). Support is limited: there are no registered clinical trials in the data compiled for this report, and 1 double-blind comparative study (100 outpatients, 1981) plus several reviews. The evidence level is L2, and the recommended decision is Hold.

Quick Overview

Item	Content
Original Indication	Not recorded in the local data
Predicted New Indication	Insomnia (disease)
TxGNN Prediction Score	1.0000
Evidence Level	L2
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?

Diazepam is a positive allosteric modulator of GABA-A receptors. It increases the effect of the brain’s main inhibitory neurotransmitter, which produces sedative, hypnotic, anxiolytic and muscle-relaxant effects. Detailed mechanism-of-action data were not available in the compiled data, but this pharmacology is well established for the benzodiazepine class.

Shortened sleep latency and better sleep maintenance follow naturally from enhanced GABA-A signalling, so the mechanistic link to insomnia is plausible. Benzodiazepines are already used for short-term insomnia, and one small double-blind study (PMID 6113175) examined diazepam in insomnia directly.

The supporting evidence is nonetheless indirect. Most of the retrieved literature consists of reviews, herbal medicine studies, and pharmacokinetic or safety discussions. There are no modern placebo-controlled trials of diazepam for insomnia. The literature also raises concerns about long-term use, including dependence, effects on sleep architecture, and a reported association with breast cancer.

Clinical Trial Evidence

Currently no related clinical trials registered.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
6113175	1981	Double-blind comparative trial	J Int Med Res	100 outpatients with insomnia received lormetazepam 1 mg or diazepam 5 mg for 7 days. Lormetazepam was significantly better on time to fall asleep (p<0.05) and sleep continuity.
39581171	2024	Review	Bioorg Chem	Reviews GABA-A receptor modulators, including diazepam, in neurological and psychiatric disorders such as insomnia. Notes sedation-related side effects.
40583063	2025	Cohort	Cell Mol Biol Lett	Long-term use of benzodiazepines and Z-drugs (including diazepam) is associated with an increased risk of breast cancer, with proposed molecular mechanisms.
36692463	2023	Meta-analysis	Acta Pharm	Examines tranquilizers in elderly patients with chronic non-communicable diseases, covering dose, outcomes and adverse effects.
23330992	2013	Review	Expert Opin Drug Metab Toxicol	Pharmacokinetics of anxiolytic drugs, which are widely prescribed for anxiety and insomnia.
31770357	2019	Review	Med Lett Drugs Ther	Overview of cannabis and cannabinoids. Only indirectly relevant to diazepam in insomnia.
6114852	1981	Review	Drugs	Review of triazolam in insomnia. Describes how shorter-acting benzodiazepines suit hypnotic use better than longer-acting ones.
35196378	2022	Non-randomised intervention	Fam Pract	Discontinuation of chronic benzodiazepine use in primary care. Highlights the need for safe withdrawal protocols.
37984023	2024	Predictive model	Value Health Reg Issues	Benzodiazepines are widely prescribed for anxiety and insomnia. Long-term use is linked to memory loss, dependence, falls and accident risk.
16671957	2006	Survey	Fundam Clin Pharmacol	Prescribing habits for benzodiazepines among physicians in Dakar. Raises concerns about dependence and unclear indications.

Australia Market Information

ARTG Number	Product Name	Dosage Form	Approved Indication
2669L	Diazepam Elixir	Oral liquid 10 mg per 10 mL, 100 mL	Not recorded in the local data

Safety Considerations

Label-based warnings and contraindications were not available in the compiled data. Please refer to the TGA-approved Product Information (PI) for these.

Long-term use concerns (from the literature): dependence and withdrawal difficulties, changes to sleep architecture with chronic use, cognitive effects and falls in older adults, and an association with breast cancer in long-term benzodiazepine and Z-drug users (PMID 40583063).
Drug interactions: The interaction search returned 100 interacting drugs. Examples from the first 20 are:
- Major: morphine (additive central nervous system and respiratory depression).
- Moderate: bupropion, aprepitant, omeprazole, esomeprazole, cimetidine, clarithromycin, cisapride, clotrimazole, miconazole, dronabinol and metoclopramide.
- Minor: dexamethasone, betamethasone and several antacids (magnesium oxide, aluminium hydroxide, calcium carbonate, magaldrate, magnesium carbonate, magnesium hydroxide).

Conclusion and Next Steps

Decision: Hold

Rationale: The only study of diazepam in insomnia is a small 7-day double-blind comparison with lormetazepam (PMID 6113175), which does not meet the placebo-controlled Phase 3 standard, so the evidence level is L2. The rest of the literature is indirect, and the safety concerns around dependence and long-term use are significant.

To proceed, the following is needed:

Placebo-controlled or active-comparator trials of diazepam in insomnia using current methods.
A comparison against current first-line options, including cognitive behavioural therapy for insomnia and newer hypnotics.
Label-based warnings, contraindications and mechanism data from the TGA-approved Product Information.
A dependence, withdrawal and older-adult risk-management plan.
Confirmation of the approved indication text for the ARTG-listed product.

Disclaimer

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