Dizocilpine (MK-801) is an antagonist of the N-methyl-D-aspartate (NMDA) receptor in the glutamate category involved with the central nervous system (CNS). The drug displays a variety of physiological actions, many of which involve the CNS, such as anesthetic and anticonvulsant properties. It penetrates readily into CNS and was described as the agent with central sympathomimetic properties. Co-administration of dizocilpine with psychostimulants, such as cocaine, amphetamine and nicotine, has been reported to prevent the development of behavioural sensitization to these drugs as well as associated neuroadaptations in rodents. However, studies with bromocriptine have suggested that co-administration of dizocilpine might merely cause sensitization to become state-dependent. A single injection of MK-801 to rats models both positive and negative symptoms of schizophrenia. Treatment of mice with dizocilpine induced learning impairment.

Pafuramidine or DB289, [2,5-bis-(4-amidinophenyl)furan bis-O-methylamidoxime] is a pro-drug of DB75, [2,5-bis(4-amidinophenyl)furan] also known as furamidine. The biotransformation process of DB289 to DB75 in the human liver consists of three O-demethylation reactions catalyzed by the Cyp4F enzyme subfamily and three N-dehydroxylation reactions catalyzed by cytrochrome b5 and NADH-cytochrome b5 reductase. DB289 was studied for therapeutic treatment against human African trypanosomiasis, Pneumocystis pneumonia and malaria. In November 2006, Immtech Pharmaceuticals, Inc. announced that the U.S. Food and Drug Administration (FDA) had granted orphan drug designation for pafuramidine (DB289) to treat Pneumocystis jiroveci pneumonia (PCP), a common life-threatening opportunistic infection in HIV/AIDS and other immunosuppressed patients. Despite the high efficacy of DB289 in patients, the mechanism of action of DB75 is unknown. The mechanism of antimicrobial activity of diamidine compounds is incompletely understood. They undergo active uptake by purine transporter systems in trypanosomes and their mechanism of action may involve interference with DNA-associated enzymes inhibition of heme crystallization11 or/and collapse of the transmitochondrial membrane potential.

Corticosterone is an adrenocortical steroid, the major glucocorticoid that has modest but significant activities as a mineralocorticoid and a glucocorticoid. Corticosterone is of minor importance in humans but is known, that it has a profound effect on the structure and function of the hippocampus. Brain corticosterone may involve memory storage and emotional stress might cause increases in plasma corticosterone.

Phencyclidine is an illegal, hallucinogenic drug that was initially used as an anesthetic agent in the 1950s and early 1960s, but was then withdrawn in 1965 because of dissociative hallucinogenic effects that were often disturbing and sometimes severe and prolonged. Phencyclidine is a noncompetitive NMDA (N-methyl-D-aspartate) receptor antagonist and glutamate receptor antagonist, but also interacts with other receptor sites, and may have effects with dopamine, opioid and nicotinic receptors. Phencyclidine disrupts the functioning of receptors for the neurotransmitter glutamate, which plays a major role in the perception of pain as well as in learning, memory, and emotion. It also influences the actions of the neurotransmitter dopamine, which causes the euphoria associated with drug use. Phencyclidine overdose deaths may occur after taking a large dose, though many phencyclidine related deaths result from delusions and other psychological consequences of the drug’s use. There have been reports of death due to accidental drowning, leaping from high places, and motor vehicle accidents in addition to violent episodes of self-mutilation, suicides, and homicides.

Elacytarabine (CP-4055 or araC-5'elaidic acid ester) is a lipid-conjugated derivative of the nucleoside analog cytarabine. Elacytarabine blocks cell division and may kill cancer cells. It is a type of antimetabolite. It was studied in clinical trials for the treatment of solid tumors. In preclinical and clinical studies, elacytarabine has demonstrated both safety and efficacy in acute myeloid leukemia (AML), with noteworthy activity among the cytarabine-refractory AML population. Elacytarabine was granted orphan drug designation status from the European Commission in 2007 and from the US FDA in 2008, with a fast-track approval designation from the FDA in 2010. Elacytarabine development has been discontinued.