Targeting the sigma-1 receptor chaperone in the treatment of perinatal brain injury

Fluvoxamine for the Early Treatment of SARS-CoV-2 Infection: A Review of Current Evidence

SARS-CoV-2 infection causes COVID-19, which frequently leads to clinical deterioration and/or long-lasting morbidity. Academic and governmental experts throughout the USA met in 2021 to discuss the potential for use of fluvoxamine as early treatment of SARS-CoV-2 infection. Fluvoxamine is a selective serotonin reuptake inhibitor (SSRI) that is a strong sigma-1 receptor agonist, and this may effectively reduce cytokine production, preventing clinical deterioration. This repurposed psychiatric medication has a well-known safety record, is inexpensive, easy to use, and widely available, all of which are advantages during this global COVID-19 pandemic. At the meeting, experts reviewed the existing published literature on the use of fluvoxamine as experimental COVID-19 treatment, as well as prior research on the potential mechanisms for anti-inflammatory effects of fluvoxamine, including for other conditions including sepsis. Investigators shared current trials underway and existing gaps in knowledge. Two randomized controlled trials and one observational study examining the effect of fluvoxamine in COVID-19 treatment have found high efficacy. Four larger randomized clinical trials are currently underway, including three in the USA and Canada. More data are needed on dosing and mechanisms of effect; however, fluvoxamine appears to have substantial potential as a safe and widely available medication that could be repurposed to ameliorate serious COVID-19-related morbidity and mortality. As of April 2021, fluvoxamine was mentioned in the NIH COVID-19 treatment guidelines, although no recommendation is made for or against use. Available data may warrant clinician discussion of fluvoxamine as a treatment option for COVID-19, using shared decision making. Video Abstract.

Sigma-1 Receptor Agonists and Their Clinical Implications in Neuropsychiatric Disorders

Accumulating evidence suggests that sigma-1 receptors play a role in the pathophysiology of neuropsychiatric diseases, as well as in the mechanisms of some selective serotonin reuptake inhibitors (SSRIs). Among the SSRIs, the order of affinity for sigma-1 receptors is as follows: fluvoxamine > sertraline > fluoxetine > escitalopram > citalopram >> paroxetine. Some SSRIs (e.g., fluvoxamine, fluoxetine and escitalopram) and other drugs (donepezil , ifenprodil , dehydroepiandeterone (DHEA)) potentiate nerve-growth factor (NGF)-induced neurite outgrowth in PC12 cells, and these effects could be antagonized by the selective sigma-1 receptor antagonist NE-100. Furthermore, fluvoxamine, donepezil, and DHEA, but not paroxetine or sertraline, improved phencyclidine-induced cognitive deficits in mice, and these effects could be antagonized by NE-100. Several clinical studies showed that sigma-1 receptor agonists such as fluvoxamine and ifenprodil could have beneficial effects in patients with neuropsychiatric disorders. In this chapter, the authors will discuss the role of sigma-1 receptors in the mechanistic action of some SSRIs, donepezil, neurosteroids, and ifenprodil, and the clinical implications for sigma-1 receptor agonists .