Prazepam is a benzodiazepine derivative and is indicated to treat symptoms of anxiety. Benzodiazepines are used to treat severe incapacitating symptoms or symptoms leading to an extreme suffering for the patient. Prazepam is believed to stimulate GABA receptors in the ascending reticular activating system. Since GABA is inhibitory, receptor stimulation increases inhibition and blocks both cortical and limbic arousal following stimulation of the brain stem reticular formation. Prazepam is a prodrug for N-desmethyl-diazepam, which is responsible for the therapeutic effects of prazepam. Prazepam was discontinued in USA.

Pemoline is a central nervous system stimulant. Pemoline is structurally dissimilar to the amphetamines and methylphenidate. Pemoline is generally considered dopaminergic, but its precise method of action hasn't yet been definitively determined. The interaction of pemoline with other drugs has not been studied in humans. The following are adverse reactions in decreasing order of severity within each category associated with pemoline: hepatic dysfunction, aplastic anemia, convulsive seizures, hallucinations, insomnia, anorexia and weight loss.

Mazindol is an amphetamine-like medicine which was developed by Sandoz in 1967 and approved by FDA for the treatment of obesity and Duchenne muscular dystrophy under the names Sanorex and Mazanor. The exact mechanism of action is unknown, but possibly involves the stimulation of beta-adrenergic receptors and inhibition of monoamine reuptake. Both Sanorex and Mazanor were withdrawn from the market by reason other than safety. NLS Pharma now is developing mazindol for Attention Hyperactivity Disorder in adults (phase II).

CHLORAL BETAINE, a chemical complex of chloral hydrate and betaine, is a nonbarbiturate sedative and hypnotic. It is indicated for sleep induction, preoperative sedation, and daytime sedation. CHLORAL BETAINE is converted to chloral hydrate in the body and its action on the central nervous system is identical with that of chloral hydrate.

Mebutamate (Capla, Dormate) is a biscarbamate drug that has anxiolytic, sedative, and antihypertensive effects. It is marketed under many trade names, including Capla and Dormate. Its preparation was reported in a 1959 US patent to Carter Products. It is less well known that mebutamate is also hypnotic. In a 1967 study, L. Tetreault, P. Richer, and J. M. Bordeleau in Montreal found that, at a dose of 600 mg, mebutamate has hypnotic properties that “affect the duration and quality of sleep induction, and the duration and quality of sleep, without disturbing the state of the subject upon awakening and during the morning.” A higher dose (900 mg) did not change the overall effect, which was “consistently between that of secobarbital at 200 mg and 100 mg.” The authors did not observe any significant side effects. Mebutamate is one of many GABAergic drugs which act via allosteric agonism of the GABAA receptor at the β-subreceptor similar to barbiturates. In contrast, benzodiazepines act at the α-subreceptor. As such, carbamates and barbiturates, possess analgesic properties which the benzodiazepine class of drugs does not.

Petrichloral is the tetrahemiacetal pentaerythritol derivative of chloral. Animal trials and studies among institutionalized patients offer clinical evidence as to the therapeutic relationship between the drugs. Petrichloral exhibits a hypnotic and sedative action similar to chloral hydrate. It is better tolerated than the later drug.

Ethinamate was used to treat insomnia (trouble in sleeping) under the brand name VALMID, but then was replaced by other more efficacy medicines. The mechanism of action was not known. However, was studies, which showed that ethinamate inhibits carbonic anhydrases I and did not inhibit II. Nevertheless, even inhibition carbonic anhydrases I is not sufficiently strong to implicate carbonic anhydrases I in the mechanism of action.

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.

Mephobarbital us a barbiturate derivative used primary as an anticonvulsant, but also as a sedative and anxiolytic. Marketing of mephobarbital was discontinued in 2012.

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.