Beyond "Psychotropic": Repurposing Psychiatric Drugs for COVID-19, Alzheimer's Disease, and Cancer.

Importance: "Psychotropic" drugs have widespread reach and impact throughout the brain and body. Thus, many of these drugs could be repurposed for non-psychiatric indications of high public health impact.Observations: The selective serotonin reuptake inhibitor (SSRI) fluvoxamine was shown efficacious as a COVID-19 treatment based on randomized controlled trials (RCTs), and a benefit of other antidepressants has been posited based on observational and preclinical studies. In this review, we illuminate features of SSRIs and other psychiatric drugs that make them candidates to repurpose for non-psychiatric indications. We summarize research that led to fluvoxamine's use in COVID-19 and provide guidance on how to use it safely. We summarize studies suggestive of benefit of other antidepressants versus COVID-19 and long COVID. We also describe putative mechanisms of psychiatric drugs in treating long COVID, Alzheimer's disease, cancer, and other conditions.Conclusion and Relevance: There is a potentially great clinical and public health impact of psychotropic drug repurposing. Challenges exist to such repurposing efforts, but solutions exist for researchers, regulators, and funders that overcome these challenges.

SSRIs differentially modulate the effects of pro-inflammatory stimulation on hippocampal plasticity and memory via sigma 1 receptors and neurosteroids.

Certain selective serotonin reuptake inhibitors (SSRIs) have anti-inflammatory effects in preclinical models, and recent clinical studies suggest that fluvoxamine can prevent deterioration in patients with COVID-19, possibly through activating sigma 1 receptors (S1Rs). Here we examined potential mechanisms contributing to these effects of fluvoxamine and other SSRIs using a well-characterized model of pro-inflammatory stress in rat hippocampal slices. When hippocampal slices are exposed acutely to lipopolysaccharide (LPS), a strong pro-inflammatory stimulus, basal synaptic transmission in the CA1 region remains intact, but induction of long-term potentiation (LTP), a form of synaptic plasticity thought to contribute to learning and memory, is completely disrupted. Administration of low micromolar concentrations of fluvoxamine and fluoxetine prior to and during LPS administration overcame this LTP inhibition. Effects of fluvoxamine required both activation of S1Rs and local synthesis of 5-alpha reduced neurosteroids. In contrast, the effects of fluoxetine did not involve S1Rs but required neurosteroid production. The ability of fluvoxamine to modulate LTP and neurosteroid production was mimicked by a selective S1R agonist. Additionally, fluvoxamine and fluoxetine prevented learning impairments induced by LPS in vivo. Sertraline differed from the other SSRIs in blocking LTP in control slices likely via S1R inverse agonism. These results provide strong support for the hypothesis that S1Rs and neurosteroids play key roles in the anti-inflammatory effects of certain SSRIs and that these SSRIs could be beneficial in disorders involving inflammatory stress including psychiatric and neurodegenerative illnesses.

Opportunities for Drug Repurposing of Serotonin Reuptake Inhibitors: Potential Uses in Inflammation, Infection, Cancer, Neuroprotection, and Alzheimer's Disease Prevention.

Serotonin reuptake inhibitors (SRIs) are safe and widely used for a variety of indications including depressive disorders, anxiety, and chronic pain. Besides inhibiting the serotonin transporter, these medications have broad-spectrum properties in many systems. Their roles have been studied in cancer, Alzheimer's disease, and infectious processes. The COVID-19 pandemic highlighted the importance of drug repurposing of medications already in use. We conducted a narrative review of current evidence and ongoing research on drug repurposing of SRIs, with a focus on immunomodulatory, antiproliferative, and neuroprotective activity. SRIs may have clinical use as repurposed agents for a wide variety of conditions including but not limited to COVID-19, Alzheimer's disease, and neoplastic processes. Further research, particularly randomized controlled trials, will be necessary to confirm the utility of SRIs for new indications.

Acute Symptoms of Mild to Moderate COVID-19 Are Highly Heterogeneous Across Individuals and Over Time.

BACKGROUND: The symptoms of coronavirus disease 2019 (COVID-19) appear to be heterogenous, and the typical course of these symptoms is unknown. Our objectives were to characterize the common trajectories of COVID-19 symptoms and to assess how symptom course predicts other symptom changes as well as clinical deterioration. METHODS: One hundred sixty-two participants with acute COVID-19 responded to surveys up to 31 times for up to 17 days. Several statistical methods were used to characterize the temporal dynamics of these symptoms. Because 9 participants showed clinical deterioration, we explored whether these participants showed any differences in symptom profiles. RESULTS: Trajectories varied greatly between individuals, with many having persistently severe symptoms or developing new symptoms several days after being diagnosed. A typical trajectory was for a symptom to improve at a decremental rate, with most symptoms still persisting to some degree at the end of the reporting period. The pattern of symptoms over time suggested a fluctuating course for many patients. Participants who showed clinical deterioration were more likely to present with higher reports of severity of cough and diarrhea. CONCLUSIONS: The course of symptoms during the initial weeks of COVID-19 is highly heterogeneous and is neither predictable nor easily characterized using typical survey methods. This has implications for clinical care and early-treatment clinical trials. Additional research is needed to determine whether the decelerating improvement pattern seen in our data is related to the phenomenon of patients reporting long-term symptoms and whether higher symptoms of diarrhea in early illness presages deterioration.

Fluvoxamine vs Placebo and Clinical Deterioration in Outpatients With Symptomatic COVID-19: A Randomized Clinical Trial.

Importance: Coronavirus disease 2019 (COVID-19) may lead to serious illness as a result of an excessive immune response. Fluvoxamine may prevent clinical deterioration by stimulating the σ-1 receptor, which regulates cytokine production. Objective: To determine whether fluvoxamine, given during mild COVID-19 illness, prevents clinical deterioration and decreases the severity of disease. Design, Setting, and Participants: Double-blind, randomized, fully remote (contactless) clinical trial of fluvoxamine vs placebo. Participants were community-living, nonhospitalized adults with confirmed severe acute respiratory syndrome coronavirus 2 infection, with COVID-19 symptom onset within 7 days and oxygen saturation of 92% or greater. One hundred fifty-two participants were enrolled from the St Louis metropolitan area (Missouri and Illinois) from April 10, 2020, to August 5, 2020. The final date of follow-up was September 19, 2020. Interventions: Participants were randomly assigned to receive 100 mg of fluvoxamine (n = 80) or placebo (n = 72) 3 times daily for 15 days. Main Outcomes and Measures: The primary outcome was clinical deterioration within 15 days of randomization defined by meeting both criteria of (1) shortness of breath or hospitalization for shortness of breath or pneumonia and (2) oxygen saturation less than 92% on room air or need for supplemental oxygen to achieve oxygen saturation of 92% or greater. Results: Of 152 patients who were randomized (mean [SD] age, 46 [13] years; 109 [72%] women), 115 (76%) completed the trial. Clinical deterioration occurred in 0 of 80 patients in the fluvoxamine group and in 6 of 72 patients in the placebo group (absolute difference, 8.7% [95% CI, 1.8%-16.4%] from survival analysis; log-rank P = .009). The fluvoxamine group had 1 serious adverse event and 11 other adverse events, whereas the placebo group had 6 serious adverse events and 12 other adverse events. Conclusions and Relevance: In this preliminary study of adult outpatients with symptomatic COVID-19, patients treated with fluvoxamine, compared with placebo, had a lower likelihood of clinical deterioration over 15 days. However, the study is limited by a small sample size and short follow-up duration, and determination of clinical efficacy would require larger randomized trials with more definitive outcome measures. Trial Registration: ClinicalTrials.gov Identifier: NCT04342663.