Succinobucol (also known as AGI-1067) is a probucol derivative patented by American pharmaceutical company Atherogenics, Inc as vascular protectant with antioxidant, anti-inflammatory and antiplatelet activities. In vitro, succinobucol inhibits the TNF-α induced expression of VCAM-1 and MCP-1 with little effect on intercellular adhesion molecule (ICAM)-1. In addition, succinobucol inhibits lipopolysaccharide (LPS)-induced expression of tissue factor in human monocytic cells and endothelial cells, an effect thought to be mediated independently from the nuclear factor κB pathway. Preclinical studies have shown reduced total cholesterol and low-density lipoprotein cholesterol concentrations, increased high-density lipoprotein cholesterol concentrations, decreased levels of inflammatory mediators, and reduced atheroma area with Succinobucol treatment in animal models. Unfortunately, in clinical trials, Succinobucol failed to demonstrate a strong cardioprotective effect. Undesired metabolic effects including high-density lipoprotein cholesterol-lowering have been consistently reported, and diarrhea appears to be an expected adverse effect.