Vanoxerine, also known as GBR-12909, is a piperazine derivative exhibiting potent selective inhibition of sodium-dependent dopamine reuptake transporters. Vanoxerine has been in clinical trials for Parkinsonism, depression and cocaine addiction but lacked efficacy. Vanoxerine has also been observed as a potent blocker of the following channels: cardiac hERG/IKr potassium channel, Calcium channel, voltage-dependent, L type, alpha 1C subunit (also known as Cav1.2) and voltage-gated sodium channel Nav 1.5. Vanoxerine was studied as a potential treatment for atrial fibrillation. However, phase III clinical trials for this condition were terminated because of cardiac safety concerns. Research also indicates that vanoxerine may have additional mechanisms of action including antagonist action at nicotinic acetylcholine receptors (nAChRs).

Tecastemizole (aka Norastemizole) is an H1 receptor antagonist that showed great promise as potential next-generation antihistamine allergy medication. Sepracor developed Norastemizole through phase III clinical trials; however, the FDA rejected the application for approval on the grounds of an unacceptable profile of adverse side-effects including phospholipidosis and cardiomyopathies in animals exposed to the drug.

Rottlerin is a principal phenolic compound of the Kamala plant Mallotus philippinensis. It was thought to be a selective inhibitor of PKCδ (protein kinase Cδ) (IC50=3-6 uM). It also inhibits PKCα, PKCβ, PKCγ, PKCε, PKCη, PKCζ and eEF2K (CaMK III) (IC50 = 5.3 uM). In HT1080 human fibrosarcoma cells, rottlerin induces apoptosis and autophagy via a PKCδ-independent pathway. When tested on HERG channels, rottlerin increased both step and tail HERG current by leftward shifting the voltage and dependence of HERG activation and slowing channel deactivation. Rottlerin is an inhibitor of Chk2, MAPKAPK-2, Pim-3, PKCλ, PKCθ, Plk, PRAK, SRPK1 and an activator of AMPK and HERG. There have been a number of studies published with evidence against the role of Rotterlin as a specific PKCδ inhibitor.

Vanoxerine, also known as GBR-12909, is a piperazine derivative exhibiting potent selective inhibition of sodium-dependent dopamine reuptake transporters. Vanoxerine has been in clinical trials for Parkinsonism, depression and cocaine addiction but lacked efficacy. Vanoxerine has also been observed as a potent blocker of the following channels: cardiac hERG/IKr potassium channel, Calcium channel, voltage-dependent, L type, alpha 1C subunit (also known as Cav1.2) and voltage-gated sodium channel Nav 1.5. Vanoxerine was studied as a potential treatment for atrial fibrillation. However, phase III clinical trials for this condition were terminated because of cardiac safety concerns. Research also indicates that vanoxerine may have additional mechanisms of action including antagonist action at nicotinic acetylcholine receptors (nAChRs).