Ethchlorvynol is used to treat insomnia (trouble in sleeping). It developed by Pfizer in the 1950s. In the United States it was sold by Abbott Laboratories under the tradename Placidyl. Although the exact mechanism of action is unknown, ethchlorvynol appears to depress the central nervous system in a manner similar to that of barbiturates – by means of GABA-A receptors modulation. Moderate side effects are: Skin rash or hives; dizziness or faintness; unusual excitement, nervousness, or restlessness. It is addictive and after prolonged use can cause withdrawal symptoms including convulsions, hallucinations, and memory loss.

Methyprylon (brand name Noludar) is a sedative agent, which used to treat insomnia. But then the drug was replaced in the market by another drugs with less side effects. The precise mechanism of action is not known, but was made suggestion, that methyprylon increases the effects of gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter in the brain.

HEPTABARBITAL is an intermediate or short term barbiturate. It binds to the GABAA receptor at either the alpha or the beta subunit. This GABAA receptor binding decreases input resistance, depresses burst and tonic firing, especially in ventrobasal and intralaminar neurons, while at the same time increasing burst duration and mean conductance at individual chloride channels; this increases both the amplitude and decay time of inhibitory postsynaptic currents. HEPTABARBITAL was formerly used as a sedative and hypnotic drug.

Pyrithyldione is a sedative and hypnotic drug. It was demonstrated that drug has certain advantages over the barbiturates. It was indicated in mild cases of insomnia and in small doses as a sedative agent during the day. Pyrithyldione was withdrawn from the marked due to several cases of agranulocytosis.

Secobarbital sodium, a barbiturate, is FDA approved for the treatment of insomnia and for pre-anesthetic use. This drug binds at a distinct site associated with a Cl- ionopore at the GABAA receptor, increasing the duration of time for which the Cl- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged. Adverse reactions are drowsiness, lethargy, hangover, paradoxical excitement in elderly patients, somnolence. Rifampin may decrease secobarbital levels by increasing metabolism.

AMOBARBITAL is a barbiturate derivative with hypnotic and sedative properties. In an in vitro study in rat thalamic slices amobarbital worked by activating GABAA receptors, which decreased input resistance, depressed burst and tonic firing, especially in ventrobasal and intralaminar neurons, while at the same time increasing burst duration and mean conductance at individual chloride channels; this increased both the amplitude and decay time of inhibitory postsynaptic currents. Adverse effects are mainly a consequence of dose-related CNS depression and the risk of dependence with continued use is high.

Butethal is a sedative and a hypnotic drug indicated for the treatment of severe intractable insomnia. It acts on receptors in the brain (GABA A receptors) causing the release of the chemical GABA. This chemical inhibits certain areas of the brain resulting in sleepiness. Common side effects are: drowsiness, sedation, unsteadiness, vertigo and inco- ordination. Also, hangover effect, paradoxical excitement, confusion, memory defects and skin rashes. Interactions may occur with the following: adrenocorticoids (cortisone-like medicine), anticoagulants (blood thinners), carbamazepine, corticotropin (barbiturates may decrease the effects of these medicines), central nervous system (CNS) depressants (using these medicines with barbiturates may result in increased CNS depressant effects), divalproex sodium, valproic acid (using these medicines with barbiturates may change the amount of either medicine that you need to take), and oral contraceptives containing estrogens (barbiturates may decrease the effectiveness of these oral contraceptives, and you may need to change to a different type of birth control).

Chloral is a chlorinated aldehyde that found extensive use, beginning in the 1940s, as a precursor in the production of the insecticide DDT and, to a lesser extent, of other insecticides and pharmaceuticals. This use of chloral has declined steadily since the 1960s, especially in those countries where the use of DDT has been restricted. Chloral is readily converted to chloral hydrate in the presence of water. Chloral hydrate is used as a sedative before medical procedures and to reduce anxiety related to withdrawal from drugs. Wider exposure to chloral hydrate occurs at microgram-per-liter levels in drinking water and swimming pools as a result of chlorination. Chloral hydrate is a well-established aneuploidogenic agent that also has some mutagenic activity. In human cells in vitro, chloral hydrate induced aneuploidy, micronuclei and gene mutations. Chloral hydrate clearly induced micronuclei in Chinese hamster cells, whereas findings in mouse lymphoma cells were conflicting. Induction of somatic mutation (but not sex-linked mutation) by chloral hydrate was demonstrated in insects. Chloral hydrate is metabolized in vivo to trichloroethanol, which is responsible for its physiological and psychological effects. The metabolite of chloral hydrate exerts its pharmacological properties via enhancing the GABA receptor complex and therefore is similar in action to benzodiazepines, nonbenzodiazepines, and barbiturates. In clinical studies, oral chloral hydrate appears to have a lower sedation failure rate when compared with oral promethazine for children undergoing pediatric neurodiagnostic procedures. The sedation failure was similar for other comparisons such as oral dexmedetomidine, oral hydroxyzine hydrochloride, and oral midazolam. When compared with intravenous pentobarbital and music therapy, oral chloral hydrate had a higher sedation failure rate. Compared to dexmedetomidine, chloral hydrate was associated with a higher risk of nausea and vomiting.

Aprobarbital is a barbiturate derivative. Aprobarbital have been used for the short-term treatment of insomnia and for routine sedation to relieve anxiety, tension, and apprehension however, barbiturates generally have been replaced by benzodiazepines.

Melatonin (5-methoxy N-acetyltryptamine) is a hormone synthesized and released from the pineal gland at night, which acts on specific high affinity G-protein coupled receptors to regulate various aspects of physiology and behaviour, including circadian and seasonal responses, and some retinal, cardiovascular and immunological functions. Melatonin is also made synthetically and available without a prescription as an over-the-counter (OTC) dietary supplement in the U.S. Melatonin supplementation has many uses, however, it has been widely studied for treatment of jet lag and sleep disorders. Parents may consider using melatonin to help their child who has a trouble falling asleep. A medical professional should always evaluate insomnia or other sleeping disorders in children. Additionally, melatonin has been shown to protect against oxidative stress in various, highly divergent experimental systems. There are many reasons for its remarkable protective potential. In mammals, melatonin binds to a number of receptor subtypes including high-affinity (MT1 and MT2) and low-affinity (MT3, nuclear orphan receptors) binding sites, which are distributed throughout the central nervous system and periphery.