Neuroprotective agents in acute ischemic stroke

Acute ischemic stroke (AIS) is the leading cause of disability and one of the top causes of mortality worldwide. The current standard of care is reperfusion therapy including intravenous thrombolysis (IVT) and thrombectomy. However, these treatments have limitations as they have a limited therapeutic window. Hence, there is a vital need to develop neuroprotective agents to prevent brain injury, extend the reperfusion window, improve mortality, and reduce disability in AIS patients. Neuroprotective agents work by counteracting the detrimental biochemical and molecular events that result in irreversible ischemic damage. Numerous preclinical studies and clinical trials have been done on different agents. Thus far, all have been definitively unsuccessful in large trials. Currently, there are several challenges in translation from animal studies to human trials. It is important to understand the current evidence as well as past challenges in the development of neuroprotective strategies in AIS in order for a more strategic selection of agents to be studied, improve study designs and thus contribute to the development of effective neuroprotective agents. Newer agents have shown promise in neuroprotection, and human trials are ongoing. In this review, the mechanisms of action of different families of neuroprotective agents were discussed. The evidence for the efficacy of different drugs in each family of neuroprotective agents was also evaluated and the current research landscape in neuroprotection for AIS was summarized. The past challenges and limitations in clinical trials and proposed possible ways to address these issues were highlighted.