Phenyl biguanide (phenylbuguanide, PBG) is a 5-hydroxytryptamine receptor 3 agonist used to study the role of serotonin receptors in the central nervous system. It has been found to trigger dopamine release in the nucleus accumbens of rats. Phenylbiguanide is used to make amanozine.

1-Phenyl-3-pyrazolidinone (phenidone) is a dual inhibitor of cyclooxygenase (COX) and lipoxygenase (LOX). Phenidone inhibits both the LO (lipoxygenase) and Cox (cyclooxygenase) pathways, the synthesis of Fos-related antigen protein, and is described as an anti-inflammatory and anti-oxidant compound. Phenidone is a potent hypotensive agent in the spontaneously hypertensive rat. Phenidone was also the best in suppressing LPS induced neurotoxicity, where the more potent neuroprotection by phenidone may be attributable to the synergistic effects of dual COX and LOX inhibition. Therefore, dual inhibitors of COX and LOX, such as phenidone, represent valuable candidates for the development of novel drugs for inflammation-related neurodegenerative disorders including PD.