GSK-1482160 is being evaluated for treatment of inflammatory pain (such as arthritis). This compound acts on P2X7 receptors, expressed by cells of innate and adaptive immunity. P2X7 receptors are involved in the production of pro-inflammatory cytokines that are thought to be an important mediator of inflammation. By blocking P2X7 receptors, less inflammatory chemicals are released, which possibly results in less inflammatory pain. Because of its ability to target P2X7R with high selectivity and to be radiolabelled with 11C, GSK-1482160 was suggested to be a useful biomarker for neuroinflammation via positron emission tomography (PET).

Nitroarginine (LNNA), an analog of L-arginine, is a competitive inhibitor of nitric oxide synthase which has been shown to prevent glutamate toxicity. Nitroarginine has been experimentally tested for its ability to prevent ammonia toxicity and ammonia-induced alterations in brain energy and ammonia metabolites. The Kd value (k(off)/k(on)) of bovine brain cNOS for LNNA was 15 nM. In contrast to the potent and slow onset of LNNA inhibition of brain cNOS, LNNA inhibition of inducible mouse macrophage NOS (iNOS) was weaker (Ki = 4.4 uM) and rapidly reversible. Thus, LNNA was a 300-fold more potent inhibitor of bovine brain cNOS than mouse macrophage iNOS. By inhibiting nitric oxide synthase LNNA causes the selective reduction of blood flow to tumor cells. Despite the potential of LNNA to function as an adjuvant in cancer therapies, its poor solubility and stability have hindered the development of an injectable formulation of LNNA that is suitable for human administration.

FGF-401 is an inhibitor of human fibroblast growth factor receptor 4 (FGFR4), with potential antineoplastic activity. Upon administration, FGF401 binds to and inhibits the activity of FGFR4, which leads to an inhibition of tumor cell proliferation in FGFR4-overexpressing cells. FGFR4 is a receptor tyrosine kinase upregulated in certain tumor cells and involved in tumor cell proliferation, differentiation, angiogenesis, and survival. FGF-401 is an FGFR4 inhibitor in phase I/II clinical studies at Novartis for the treatment of positive FGFR4 and KLB expression solid tumors and hepatocellular carcinoma.

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illegal, hallucinogenic drug that was initially used as an anesthetic agent in the 1950s and early 1960s, but was then withdrawn in 1965 because of dissociative hallucinogenic effects that were often disturbing and sometimes severe and prolonged.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.