Clinicians should tread carefully when treating elderly patients with two drugs newly cleared for use in COVID-19 patients, says a top industry doctor.

The Food and Drug Administration on Saturday issued emergency use authorization for hydroxychloroquine and chloroquine, decades-old drugs used in autoimmune disease and malaria therapy. And while preliminary research hints that the drugs could be beneficial, neither has yet been proven efficacious or safe in patients with the coronavirus, said Kevin O’Neil, M.D., chief medical officer, Affinity Living Group.

“As a geriatrician, I am very concerned that these drugs may have serious toxicities in the older adult population,” O’Neil cautioned Affinity’s physician partners shortly before the FDA’s move.

Some elders are particularly at risk from potential side effects, the doctor told McKnight’s on Monday. “Many older adults have some degree of kidney impairment or liver disease, which may be augmented by these drugs,” he said. 

In addition, both drugs are associated with adverse effects such as cardiac arrhythmias, skin reactions, neuromuscular problems, and potentially life-threatening anemia. “Severe lowering of blood sugar has occurred even when [patients are] not on antidiabetic drugs,” O’Neil said.

The urge to help a seriously ill patient in the absence of an alternative treatment is understandable, O’Neil acknowledged. “To wait for the results of a well-designed clinical study can take weeks or months. In situations like this, I can understand the compassionate use of these drugs as long as patients and their families understand the risks,” he said. But he added that he is reminded of past harms that have come from attempts to rush the use of drugs before full-scale studies are complete.

Meanwhile, if the drugs are used in mild cases of COVID-19 or for prevention, patients with rheumatoid arthritis and lupus may be left without access, O’Neil said. In fact, demand for hydroxychloroquine and chloroquine has recently skyrocketed, prompting fears of hoarding and scarcity.

The emergency use authorization allows the drugs to be donated to a national stockpile, according to the Department of Health and Human Services. Another emergency use authorization under consideration is meant to boost manufacturing of the drugs, according to Politico.