In the recent flap over chloroquine and its relative hydroxychloroquine, drugs seen as promising in many quarters for use in treating COVID-19 patients, one commentator typical of many sternly proclaimed that these compounds “have NOT been proven effective against” the novel coronavirus. Implication: These are drugs no reasonable person would want to take, nor a reasonable doctor prescribe.

And yet, as Arizona physician Jeffrey Singer notes, “Doctors around the globe, including the U.S., are using these and other drugs to treat their patients, and reporting on their findings in the peer-reviewed medical literature.” It’s both legal and utterly routine for doctors to prescribe a drug for indications other than the one for which it has been approved — so-called “off-label prescribing.” In fact, an estimated 20% of pharmaceuticals reach patients that way. (More on the practice herehere, and here.) And this will be true almost by definition for a newly emergent malady, for which there will be no compounds proven effective yet.

The catchphrase “has not been proven effective” is, in truth, more a legal statement than a medical one, and there’s at least one reason why it’s so widely used. Drug companies face stringent penalties, along with potential criminal liability and settlements running into the billions of dollars, if they are found to have promoted doctors’ off-label use of a drug, no matter whether it worked as intended and benefited the patient. Nor can they readily bump the drug from the one category to the other, because the process of proving a compound effective to the satisfaction of the FDA is typically prolonged and expensive. Further muddying the waters, some critics of the pharmaceutical industry see fit to stigmatize off-label prescribing, making it sound somehow underhanded or sneaky.

As James Copland notes at City Journal, the pharmaceutical company Bayer can describe chloroquine phosphate as a drug that “shows potential” only in the context of donating 3 million tablets for free to the United States. Had it tried to use the same language in the context of selling the same drug, even at production cost, it would have faced untold legal woe. In a saner world at a calmer time, we might want to reconsider the FDA ban on promotion, especially since it sometimes impedes getting the word to doctors about therapies that are the most hopeful current bets or are accepted as part of an optimal standard of care.

There’s a good chance that if some compounds prove useful against COVID-19, the first such will be discovered among those already prescribed for other indications. Among the very first research pushes in drug science against the novel virus have been to develop a list of known compounds that show action against it in a lab setting or by targeting proteins the virus relies on. Since dozens of those compounds are currently approved for other indications, if they do turn out to make the difference for some COVID-19 patients, it will be another instance, among many, of drugs that are prescribed off-label and save lives.