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 Both Sanorex and Mazanor were withdrawn from the market by reason other than safety.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).

Triclofos is primarily indicated in conditions like Insomnia, and can also be given in adjunctive therapy as an alternative drug of choice in Nausea, vertigo, labyrinthine disorders. It is also used sedate people suffering from anxiety or tension before medical investigations. Triclofos is converted to Trichloroethanol in the body .This act on brain and produces sleep. Trichloroethanol decreases time taken to fall asleep and lengthen the sleep. Triclofos is most commonly used agent for sedation in neonates as well as in older infants and children in Japan.

Enflurane (2-chloro-1,1,2,-trifluoroethyl-difluoromethyl ether) is a halogenated ether structural isomer of isoflurane. Developed by Ross Terrell in 1963, it was first used clinically in 1966. It was increasingly used for inhalational anesthesia during the 1970s and 1980s but is no longer in common use. Clinically, enflurane produces a dose-related depression of myocardial contractility with an associated decrease in myocardial oxygen consumption. Between 2% and 5% of the inhaled dose is oxidized in the liver, producing fluoride ions and difluoromethoxy-difluoroacetic acid. This is significantly higher than the metabolism of its structural isomer isoflurane. The exact mechanism of the action of general anesthetics has not been delineated. Enflurane acts as a positive allosteric modulator of the GABAA, glycine, and 5-HT3 receptors, and as a negative allosteric modulator of the AMPA, kainate, and NMDA receptors, as well as of nicotinic acetylcholine receptors.

L-threonine is an essential amino acid. Threonine is a precursor of glycine. The biochemical studies on rats proved that glycine is synthesized from threonine (through threonine dehydrogenase pathway). Threonine dehydrogenase is the key enzyme in mammals like pigs, cat, and rats for degradation of 80% threonine. In adult humans, degradation of 7–11% of threonine is done by threonine dehydrogenase. The human L-threonine 3-dehydrogenase gene (GeneID: 157739, UniProtKB: Q8IZJ6 (TDH_HUMAN)) is an expressed pseudogene having lost the splice acceptor site preceding exon 6 and codon arginine-214 (CGA) is mutated to a stop codon (TGA). A few trials demonstrated that oral L-threonine may alleviate clinical signs of amyotrophic lateral sclerosis and spasticity in humans. L-Threonine has recently been brought into agricultural industry for balancing the livestock feed.

Phenylalanine is a biologically essential amino acid that acts as a precursor to tyrosine and the catecholamines (epinephrine, norepinephrine, dopamine, and tyramine), and is a constituent of many central nervous system neuropeptides. Normal dietary levels of phenylalanine are approximately 1-2 grams daily. Phenylalanine appears in two forms which are identical mirror images of each other: L-phenylalanine, a nutritional supplement, and D-phenylalanine, an effective painkiller and antidepressant due to its ability to inhibit the breakdown of enkephalins, the brain’s natural pain killers.

Tryptophan is alpha-aminoacid that is used in the biosynthesis of proteins. It is essential aminoacid in humans, meaning the body cannot synthesize and it must be obtained from the diet. Tryptophan is a precursor of serotonin, and as such is sold over the counter in many countries as a dietary supplement for use as an antidepressant, anxiolytic and sleep aid, however application of tryptophan in these indications is not approved by FDA.

Lysing is an essential basic amino-acid encoded by codone AAA and AAG, and used in the biosynthesis of proteins. The daily requirement for lysine is 38 mg/kg body weight. The most rich source of lysine is fish, beef, chicken. In a clinical study lysine supplements was found to be an effective for reduction of occurrence, severity and healing time for recurrent HSV infection, however Cochrane Review concluded that the evidence is insufficient. Lysine was investigated for improving anxiety, ameliorating angina prectoris. Lysine acetylsalicylate has been used to treat pain and to detoxify the body after heroin use. Lysine clonixinate has been used for its analgesic properties for the treatment of migraine headaches and other painful conditions. However, limited clinical trials exist for these conditions.

Histidine is an essential amino acid. L-histidine is converted to histamine by histidine decarboxylase, a pyridoxal 5'-phosphate-dependent enzyme. The copper(II)–l-histidine (1:2 complex at physiological pH) has been widely used in the treatment of Menkes disease (a genetic neurodegenerative disorder that leads to early death in the children due to impaired copper metabolism) and more recent use has been reported in the treatment of infantile hypertrophic cardioencephalomyopathy (a condition caused by mutations in SCO2, a cytochrome c oxidase assembly gene). CUSTODIOL HTK (Histidine-tryptophan-ketoglutarate) Solution is indicated for perfusion and flushing of donor kidneys, liver, and heart prior to removal from the donor or immediately after removal from the donor.

Mesoridazine (brand name Serentil) is a phenothiazine antipsychotic. It was marketed in the U.S. for the treatment of schizophrenia, behavioral problems in mental deficiency and chronic brain syndrome, alcoholism and psychoneurotic symptoms, such as anxiety and tension. Due to the risk of serious cardiac events the indicated use of Serentil was limited to severely ill schizophrenic patients who fail other therapies. Based upon animal studies, mesoridazine acts indirectly on reticular formation, whereby neuronal activity into reticular formation is reduced without affecting its intrinsic ability to activate the cerebral cortex. Mesoridazine shows a moderate adrenergic blocking activity in vitro and in vivo and antagonizes 5-hydroxytryptamine in vivo.

Butaperazine is an antipsychotic phenothiazine. As shown in animal studies butaperazine increases striatal and mesolimbic dopamine turnover. Butaperazine is effective in the management of schizophrenia. Extrapyramidal symptoms and drowsiness are the most common adverse effects.