Arbidol (Umifenovir) Safe, inexpensive antiviral drug for SARS-CoV-2 or FDA unapproved medication?

Arbidol is currently unapproved by the FDA for use in the US!

Arbidol/Umifenovir

Is a drug that is claimed to inhibit viral fusion.

Although research I have read from China indicates it may be effective as a COVID-19 prophylaxis for health workers, it remains unapproved by the US FDA and virtually unknown in the US.

It's very inexpensive, and is sold in China in a generic form for around $2/box of 10. 

Update: Antiviral treatment in Chinese hospitals seems to include Arbidol as a mainstay of treatment.
(Source: Handbook of COVID-19 Prevention
and Treatment
The First Affiliated Hospital, Zhejiang University School of Medicine)

"Antiviral Treatment
At FAHZU, lopinavir/ritonavir (2 capsules, po q12h) combined with arbidol (200 mg po
q12h) were applied as the basic regimen. From the treatment experience of 49 patients
in our hospital, the average time to achieve negative viral nucleic acid test for the first
time was 12 days (95% CI: 8-15 days). The duration of negative nucleic acid test result
(negative for more than 2 times consecutively with interval ≥ 24h) was 13.5 days (95% CI:
9.5 - 17.5 days).
If the basic regimen is not effective, chloroquine phosphate can be used on adults
between 18-65 years old (weight ≥ 50 kg: 500 mg bid; weight ≤50 kg: 500 mg bid for first
two days, 500 mg qd for following five days).
Interferon nebulization is recommended in Protocols for Diagnosis and Treatment of
COVID-19. We recommend that it should be performed in negative-pressure wards
rather than general wards due to the possibility of aerosol transmission.
Darunavir/cobicistat has some degree of antiviral activity in viral suppression test in
vitro, based on the treatment experience of AIDS patients, and the adverse events are
relatively mild. For patients who are intolerant to lopinavir/ritonavir, darunavir/ cobici-
stat (1 tablet qd) or favipiravir (starting dose of 1600 mg followed by 600 mg tid) is an
alternative option after the ethical review. Simultaneous use of three or more antiviral
drugs is not recommended."

Link to studies up to 2005 from arbidol.org (have not had the time to read them or evaluate this site, so no comment as to its validity)
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