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).

Carbromal is containing bromide mild hypnotic that has been used to mild insomnia treatment. Carbromal is one of a number of hypnotics containing bromide, which releases the bromide ion on hydrolysis in the body. It has no advantages over other hypnotics. Chronic administration can cause accumulation of bromide ions which have the same distribution as chloride ions but are not actively transported out of cells and are excreted in the urine with a half-life of 10-12 days. Bromism may result from chronic carbromal ingestion and with a plasma bromine concentration of 10-15 mM, the signs are acne, cerebral retardation, cerebellar dysfunction, hyperreflexia, extensor plantar responses, and gastro¬intestinal symptoms. The risk of bromism developing makes carbromal a more dangerous drug than most other hypnotics.

Paraldehyde is the cyclic trimer of acetaldehyde molecules. It was introduced into clinical practice in the UK by the Italian physician Vincenzo Cervello in 1882. It is a central nervous system depressant and was soon found to be an effective anticonvulsant, hypnotic and sedative. It was included in some cough medicines as an expectorant (though there is no known mechanism for this function beyond the placebo effect). Paraldehyde also has been used in the treatment of alcoholism and in the treatment of nervous and mental conditions to calm or relax patients who are nervous or tense and to produce sleep. However, this medicine has generally been replaced by safer and more effective medicines for the treatment of alcoholism and in the treatment of nervous and mental conditions.

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.

Barbital, the one of the series of barbiturates, has hypnotic, sedative, and anticonvulsant properties and used under the trade name Veronal. It calmed manic patients and helped melancholic patients to sleep and was an effective inducer of sleep in insomniacs, but at the same time compound could induced dependence. It was substituted by the butyl analog, butobarbital, which was three times stronger and its period of action was much shorter due to its lipophilicity. Barbital is a ligand of GABA-receptor complex and in addition, it could have another target, a creatine kinase.

Azaperone (Stresnil, Fluoperidol) is a pyridinylpiperazine and butyrophenone neuroleptic drug with sedative and antiemetic effects. It is mainly as a tranquilizer in veterinary medicine. Azaperone is officially indicated for the “control of aggressiveness when mixing or regrouping weanling or feeder pigs weighing up to 36.4 kg”. It is also used clinically as a general tranquilizer for swine, in particular with aggressive sows to allow piglets to be accepted, and as a preoperative agent prior to general anesthesia or cesarian section with local anesthesia. Azaperone has also been used as a neuroleptic in horses, but some horses develop adverse reactions (sweating, muscle tremors, panic reaction, CNS excitement) and IV administration has resulted in significant arterial hypotension in the horse; because of these effects, most clinicians avoid the use of this drug in equines. Azaperone appears to have minimal effects on respiration and may inhibit some of the respiratory depressant actions of general anesthetics. A slight reduction of arterial blood pressure has been measured in pigs after IM injections of azaperone, which is apparently due to slight alpha-adrenergic blockade. Azaperone has been demonstrated to prevent the development of halothane-induced malignant hyperthermia in susceptible pigs. Preliminary studies have suggested that the effects of butyrephenones may be antagonized by 4-aminopyridine. Azaperone acts primarily as a dopamine antagonist but also has some antihistaminic and anticholinergic properties as seen with similar drugs such as haloperidol. Azaperone may cause hypotension and while it has minimal effects on respiration in pigs, high doses in humans can cause respiratory depression which may be why it is rarely used in humans. Higher doses are used for anesthesia in combination with other drugs such as xylazine, tiletamine and zolazepam. Azaperone is also used in combination with strong narcotics such as etorphine or carfentanil for tranquilizing large animals such as elephants.

Clothiapine is a neuroleptic of dibenzoepine class that ise used for the treatment of mental disorders. It is supposed that clothiapine acts by blocking GABA (A) receptors. The drug is marketed in some European countries under the name Entumin.

Domitor (medetomidine hydrochloride) is indicated for use in dogs: for restraint, sedation and analgesia associated with clinical examinations and procedures, minor surgery, pre-anaesthesia and as a premedicant before thiopentone-halothane general a naesthesiaand as a premedicant before general anaesthesia with propofol. In combination with butorphanol for sedation and analgesia, and as a premedicant prior to thiopentone anaesthesia. In cats: for restraint and sedation. Medetomidine is a potent and highly selective alpha2-adrenoreceptor agonist with both central and peripheral activity, and acting both presynaptically and postsynaptically. Its primary effects are sedative and analgesic resulting from its central depressant activity. It has no local anaesthetic properties. Like other compounds of its class there are secondary effects, including bradycardia. Blood pressure is increased but then returns to normal or just below. Body temperature is decreased in a dose dependent manner and intestinal motility is also reduced. The drug has been developed by Orion Pharma. It is currently approved for dogs in the United States, and distributed in the United States by Pfizer Animal Health and by Novartis Animal Health in Canada under the product name Domitor. The marketed product is a racemic mixture of two stereoisomers; dexmedetomidine is the isomer with more useful effects, and is now marketed as Dexdomitor.