FDA grants approval for Plaquenil (hydroxychloro­quine sulfate, aka HCQ)

Hydroxychloroquine has a long history of use for the prevention of malaria.  It has been considered to be a very safe drug for several decades.

The “off label” policy of the FDA allows doctors to prescribe medications for any condition, as they see fit.  An approved drug does not need additional approvals for a doctor to choose to use it for another purpose that was not part of the initial application for approval.  Additional conditions for which a drug has been found to work may be added to the label information later, but doctors are able to prescribe for those conditions at any time after the drug’s initial approval.  Once approved, the drug is legally available for any use.

Sources:

• 
  April 18, 1955. US Food & Drug Administration. “Drugs@FDA: FDA-Approved Drugs: PLAQUENIL.”
  https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=009768.
  Food & Drug Administration.
• 
  April 18, 2019. US Food & Drug Administration. “Understanding Unapproved Use of Approved Drugs ‘Off Label.’”
  https://www.fda.gov/patients/learn-about-expanded-access-and-other-treatment-options/understanding-unapproved-use-approved-drugs-label.
  Food & Drug Administration.
• 
  Drugs.Com. “Hydroxychloroquine Uses, Dosage & Side Effects.”
  https://www.drugs.com/hydroxychloroquine.html.
  Reference.