Neurotransmitter

Class of Drug

Examples

Comments

H1 Histamine

Antihistamines (aka histamine antagonists)

Diphenhydramine, Doxylamine

Over-the-counter sleep medicines are antihistamines

GABA (Gamma-Amino Butyric acid)

Benzodiazepines

Temazepam  (Restoril) Triazolam (Halcion), Loprazolam (Havlane)

Still prescribed for insomnia, although more often for anxiety

GABA (Gamma-Amino Butyric acid)

Non-benzodiazepines: Pyrazolopyrimidines, imidazopyridines and cyclopyrrones – The”Z-drugs”

Eszopiclone (Lunesta), Zolpidem  (Ambien), Zaleplon (Sonata)

Most prescriptions for insomnia involve this class

GABA (Gamma-Amino Butyric acid)

Barbituates

Secobarbital (Seconal)

Rarely used anymore

Orexin (Hypocretin)

Orexin antagonists

Suvorexant, SB-649868

Still in development.  May become available for patient use by 2015

Melatonin MT1 and MT2 receptors

Melatonin agonists

Melatonin, Ramelteon (Rozerem)

Affect the circadian clock.  Usually have fewer side effects.

Serotonin and Dopamine

Antipsychotics and Antidepressants

Quetiapine (Seroquel), Olanzapine (Zyprexa), Doxepine (Sinequan)

Not often prescribed for sleep disorders, but for other disorders than have insomnia or hypersomnia as a symptom.

Opioid

Narcotics

Hydrocodone, Morphine

Pain medicines.  Not prescribed for sleep disorders, but cause extreme drowsiness