​​Treatment with the commonly available antidepressant fluvoxamine reduced the need for emergency care and hospitalization in high-risk patients with early COVID-19, according to a new study.

Fluvoxamine, a selective serotonin reuptake inhibitor (SSRI), is typically used to treat obsessive compulsive disorder and depression. It was considered promising as a COVID-19 drug in part due to its anti-inflammatory and possibly anti-viral effects, the researchers said. Sold under the brand name Luvox, it is a readily available and relatively inexpensive drug, they added.

In the new trial, published this week in the Lancet, almost 1,500 participants were randomly assigned to take either 100 mg of fluvoxamine twice daily or a placebo, for 10 days. All participants had positive SARS-CoV-2 tests and known risk factors for disease progression, such as older age, diabetes, hypertension, obesity, smoking, obesity, immunosuppression and/or unvaccinated status.

Participants who took fluvoxamine were less likely to have long stays in an emergency department or to be transferred to a hospital room than their peers who received a placebo. In the treated group, the absolute risk of those adverse outcomes decreased by 5%, and the relative risk decreased by 32%, the investigators reported.

The results compare favorably with the treatment effects of more expensive treatments including monoclonal antibodies for outpatient treatment, they noted.

“Given fluvoxamine’s safety, tolerability, ease of use, low cost, and widespread availability, these findings might influence national and international guidelines on the clinical management of COVID-19,” they wrote.

If further studies prove successful and the drug is approved for use, it could be most beneficial to COVID-19 ambulatory with mild disease, for whom there are few known treatments, the researchers said.

Investigators made the discovery as part of a program to vet already-approved drugs for repurposing as COVID-19 treatments. The study is only the second one to show an important treatment benefit for a repurposed drug in early COVID-19, they noted.

“From a clinical practice perspective, the results represent an important step in understanding the role of fluvoxamine for outpatients with COVID-19,” wrote Otavio Berwanger, M.D., Ph.D., of the Albert Einstein Israelite Hospital, in Brazil, in a commentary accompanying the study. 

The results strongly suggest that fluvoxamine is effective, safe, inexpensive and relatively well-tolerated by ambulatory patients with COVID-19, added Berwanger, who was not involved in the research. The drug could be particularly useful where resources are scarce, although it would not necessarily need to be limited to those settings, he concluded.