Z-type Drugs (Non-benzodiazepine hypnotics)

Primarily act on the GABA-A receptor, promoting sleep.

Zolpidem, Zaleplon, Eszopiclone

Shorter half-life than benzodiazepines, lower risk of dependence but still present.

Effective for initiating sleep; rapid onset.

Potential for dependence, parasomnias (sleepwalking, etc.), and rebound insomnia.

Benzodiazepines

Bind to the GABA-A receptor, enhancing the effect of GABA, leading to sedation.

Diazepam, Lorazepam, Temazepam

Higher risk of dependence and tolerance; generally used for short-term management.

Highly effective for anxiety and severe insomnia; muscle relaxant properties.

High risk of dependence and tolerance, significant residual sedation ("hangover effect"), and cognitive impairment.

Orexin Receptor Antagonists

Block the signaling of orexin (a wakefulness-promoting neurotransmitter).

Suvorexant, Lemborexant

A newer class of drugs that directly target wakefulness.

Low risk of dependence; a novel mechanism targeting wakefulness pathways.

May cause drowsiness; high cost; limited long-term data compared to older drugs.

Atypical Antidepressants

Some have strong sedating properties, often due to histamine (H1) antagonism.

Trazodone, Mirtazapine

Often used off-label for insomnia; typically prescribed when depression is co-morbid.

Useful when insomnia is linked to depression or anxiety; generally low dependence risk.

Orthostatic hypotension (Trazodone), weight gain (Mirtazapine), and daytime sedation.

Tricyclic Antidepressants (TCAs)

Sedation is a common side effect, mainly due to potent H1 receptor blockade.

Amitriptyline, Doxepin

Lower doses are often used for sleep than for depression; anticholinergic side effects are common.

Effective at very low doses for sleep maintenance.

Significant anticholinergic side effects (dry mouth, blurred vision, constipation), cardiac risks in overdose.

Antipsychotics

Certain agents (especially older and sedating second-generation ones) are used off-label for severe, refractory insomnia, often due to H1 antagonism.

Quetiapine, Olanzapine

Not recommended as first-line treatment due to significant metabolic and other side effects.

Highly sedating for severe, treatment-resistant insomnia.

High risk of serious side effects including weight gain, metabolic syndrome, and movement disorders.