Piperazine, a six membered nitrogen containing heterocycle, is of great significance to the rational design of drugs. This moiety can be found in a plethora of well-known drugs with various therapeutic uses, such as antipsychotic, antihistamine, antianginal, antidepressant, anticancer, antiviral, cardio protectors, anti-inflammatory, and imaging agents. Slight modification to the substitution pattern on the piperazine nucleus facilitates a recognizable difference in the medicinal potential of the resultant molecules. Piperazine has been used as an antihelmintic drug. Piperazine works by paralyzing the worms. They are then passed in the stool.

Sulfamethazine is a sulfonamide used to treat a variety of bacterial diseases in animals. It inhibits bacterial synthesis of dihydrofolic acid by competing with para-aminobenzoic acid (PABA) for binding to dihydropteroate synthetase (dihydrofolate synthetase).

Tubocurarine, a naturally occurring alkaloid, is used to treat smoking withdrawl syndrom. Tubocurarine, the chief alkaloid in tobacco products, binds stereo-selectively to nicotinic-cholinergic receptors at the autonomic ganglia, in the adrenal medulla, at neuromuscular junctions, and in the brain. Two types of central nervous system effects are believed to be the basis of Tubocurarine's positively reinforcing properties. A stimulating effect is exerted mainly in the cortex via the locus ceruleus and a reward effect is exerted in the limbic system. At low doses the stimulant effects predominate while at high doses the reward effects predominate. Intermittent intravenous administration of Tubocurarine activates neurohormonal pathways, releasing acetylcholine, norepinephrine, dopamine, serotonin, vasopressin, beta-endorphin, growth hormone, and ACTH. Tubocurarine competes with acetylcholine for post-synaptic nicotinic NM receptors and blocks them.

AMINOBENZOATE SODIUM is a salt of Aminobenzoic acid. Aminobenzoic acid is an intermediate in the synthesis of folate by bacteria, plants, and fungi. Many bacteria, including those found in the human intestinal tract such as E. coli, generate Aminobenzoic acid from chorismate by the combined action of the enzymes 4-amino-4-deoxychorismate synthase and 4-amino-4-deoxychorismate lyase. Plants produce Aminobenzoic acid in their chloroplasts, and store it as a glucose ester (pABA-Glc) in their tissues. Humans lack the enzymes to convert Aminobenzoic acid to folate, so require folate from dietary sources such as green leafy vegetables. In humans, Aminobenzoic acid is considered nonessential and, although it has been referred to historically as "vitamin Bx", is no longer recognized as a vitamin, because most people have colon bacteria that generate Aminobenzoic acid. The potassium salt is used as a drug against fibrotic skin disorders, such as Peyronie's disease, under the trade name Potaba.

Menadiol diphosphate is given as a vitamin K supplement to prevent bleeding caused by vitamin K deficiency. Vitamin K is normally obtained from the diet; for example it is found in green leafy vegetables, root vegetables, cereals and dairy products. Although it cannot be made by the human body itself, a certain amount of vitamin K is also made by bacteria that live in the gut. The body normally produces bile to help it absorb fats from the gut. In conditions where there is a problem with the production of bile, for example in certain liver diseases, or if there is a blockage of the bile duct, there can be problems absorbing fats. This can lead to vitamin K deficiency, decreased production of clotting factors and an increased risk of bleeding. In these situations, menadiol diphosphate is given as a vitamin K supplement to increase the production of clotting factors. It is water soluble so is readily absorbed from the gut. Also in 1974 was made attempt to develop tritiated derivatives of Synkavit (menadiol sodium diphosphate, MNDP) of high specific activity as a radioactive drug. Among the 203 evaluable treated cases, some form of response was observed in 23 out of 151 (15·2%) receiving the drug by intravenous injections and 13 out of 52 (25%) after intra-arterial injections. For the sites and types of malignant diseases which showed responses after either intravenous or intra-arterial administration among the 55 patients surviving at least 3 months after the first injection, some form of response was observed in 32 but only 5 of these showed either a "complete" or a "partial" response.It is concluded that further investigation is desirable. Kappadione is a Vitamin K derivative, was discontinued. It was manufactured by Eli Lilly and others Company.

Menadiol diphosphate is given as a vitamin K supplement to prevent bleeding caused by vitamin K deficiency. Vitamin K is normally obtained from the diet; for example it is found in green leafy vegetables, root vegetables, cereals and dairy products. Although it cannot be made by the human body itself, a certain amount of vitamin K is also made by bacteria that live in the gut. The body normally produces bile to help it absorb fats from the gut. In conditions where there is a problem with the production of bile, for example in certain liver diseases, or if there is a blockage of the bile duct, there can be problems absorbing fats. This can lead to vitamin K deficiency, decreased production of clotting factors and an increased risk of bleeding. In these situations, menadiol diphosphate is given as a vitamin K supplement to increase the production of clotting factors. It is water soluble so is readily absorbed from the gut. Also in 1974 was made attempt to develop tritiated derivatives of Synkavit (menadiol sodium diphosphate, MNDP) of high specific activity as a radioactive drug. Among the 203 evaluable treated cases, some form of response was observed in 23 out of 151 (15·2%) receiving the drug by intravenous injections and 13 out of 52 (25%) after intra-arterial injections. For the sites and types of malignant diseases which showed responses after either intravenous or intra-arterial administration among the 55 patients surviving at least 3 months after the first injection, some form of response was observed in 32 but only 5 of these showed either a "complete" or a "partial" response.It is concluded that further investigation is desirable. Kappadione is a Vitamin K derivative, was discontinued. It was manufactured by Eli Lilly and others Company.

Menadione bisulfite is a water-soluble analog of Vitamin K3. Pharmacologic studies on menadione bisulfate indicad that its toxicity is relatively low. In man, doses approximately ten times as great as those generally recommended for therapeutic use, given daily for a period of one week. Redox cycling compounds, such as menadione, have the potential to effectively mitigate the toxicity of organophosphorus pesticides including parathion. Menadione bisulfite behaved as a competitive inhibitor of chicken muscle aldose reductase.

Pantothenic acid (known as Vitamin B5) is a water-soluble member of the B-vitamin family that is converted into 4’-phosphopantetheine, which is then converted to co-enzyme A (CoA) via adenosine triphosphate. Pantothenic acid regulates epidermal barrier function and keratinocytes differentiation via CoA metabolism. Pantothenic acid is incorporated into co-enzyme A and protects cells against peroxidative damage by increasing the level of glutathione. A recent feasibility study has also shown that daily oral supplementation of a nutritional agent containing pantothenic acid for 8 weeks was feasible and safe. It was discovered the different pharmacological implementation of pantothenic acid, such as treatment of acne, obesity. Existed some reports, mentioned efficacy using pantothenic acid in systemic lupus erythematosus. Significant reduction in morning stiffness, degree of disability, and severity of pain was reported for persons taking pantothenic acid in case of osteoarthritis and rheumatoid arthritis. Vitamin B5 may increase the effects of a group of drugs called cholinesterase inhibitors, which are used to treat Alzheimer's disease. That might lead to severe side effects.

Sodium thiopental (also known as Sodium Pentothal, thiopental) was discovered in 1930s by investigators working for Abbott Laboratories. Thiopental sodium was used for the induction of general anesthesia and is used as an adjunct to provide hypnosis during balanced anesthesia with other anesthetic agents, including analgesics and muscle relaxants. Thiopental sodium was also used as an adjunct for control of convulsive disorders of various etiology, including those caused by local anesthetics. Finally, thiopental sodium had been used to reduce the intracranial pressure in patients with increased intracranial pressure, if controlled ventilation is provided. Nevertheless, these prescriptions of drug were discontinued. In addition, this drug was banned for use in US executions. Thiopental sodium acts through the CNS with particular activity in the mesencephalic reticular activating system. It was shown, that mechanism of action of sodium thiopental via GABAA receptor. Thiopental binds at a distinct binding 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.

Gentian violet ((GV) hexamethyl pararosaniline, also known as crystal violet, methyl violet) is a triphenylmethane dye with anti-bacterial, anti-fungal, anti-helminithic, anti-trypanosomal, anti-angiogenic and anti-tumor properties. GV has a lengthy history and has been used successfully as monotherapy and an adjunct to treatment in a variety of diseases. Gentian violet interacts with negatively charged components of bacterial cells including the lipopolysaccharide (on the cell wall), the peptidoglycan and DNA. A similar cell penetration and DNA binding process is thought to take place for fungal cells as well. Because Gentian violet is a mutagen and mitotic poison, cell growth is consequently inhibited. A photodynamic action of gentian violet, apparently mediated by a free-radical mechanism, has recently been described in bacteria and in the protozoan T. cruzi. Evidence also suggests that gentian violet dissipates the bacterial (and mitochondrial) membrane potential by inducing permeability. This is followed by respiratory inhibition. This anti-mitochondrial activity might explain gentian violet's efficacy towards both bacteria and yeast with relatively mild effects on mammalian cells.