Double-edged sword

Yi Fan, a doctor from Wuhan, contracted the virus, which left his skin darkened, while treating patients at the start of the outbreak. He has been known fondly by netizens as the "dark-faced angel", although recent photos show that his skin color has much improved.

For his peers, Yi's case serves as a reminder that COVID-19 requires scrupulous care.

During a media briefing in May, Duan Jun, a senior intensive care physician at the China-Japan Friendship Hospital in Beijing, said the skin darkening was due to a combination of the antifungal drug Polymyxin B and liver damage, which caused iron to build up in the blood.

Mao Yonghui, a senior nephrologist at Beijing Hospital who treated severe cases of COVID-19 in Wuhan, said medical workers must take the adverse effects of medication into account, as many of the powerful drugs being used can damage the liver, kidneys and gastrointestinal system.

"Most of the drugs' side effects can be mitigated through careful use and meticulous monitoring," she said. "The long-term consequences of the virus are puzzling enough, so the last thing we want is for the treatment to have any long-lasting effects."

According to the World Health Organization, no effective drugs are currently available to combat COVID-19. However, some potential candidates have recently received a considerable amount of hype and endorsement from the media and politicians. These drugs include the experimental antiviral remdesivir and dexamethasone, a steroid.

The journal Science reported that the US government recently stockpiled enough supplies of remdesivir for three months. The UK and Japan have made dexamethasone part of the care for patients in critical condition after a preliminary study found that the steroid could reduce mortality by about one-third for those on ventilators, the report said.

However, Mao said an apparent lack of reporting on the adverse effects of the drugs, which can pose long-term health risks if not taken properly, remains a concern.

"The more encouraging a candidate drug is, the more careful doctors and public health officials should be when giving it to the public," she said. "But we know such rationality is in short supply, especially during a pandemic."

The adverse effects of remdesivir in treating COVID-19 remain unclear, as the drug is still being developed. However, evidence of risk to the liver and kidneys has been reported and is under intense scientific scrutiny, according to studies published in The Lancet and New England Journal of Medicine.

A Beijing orthopedist, speaking on condition of anonymity, said he was deeply concerned when the UK and Japan rushed to approve dexamethasone as a standard treatment for critically ill COVID-19 patients, based on early evidence.

"Dexamethasone, prednisone and methylprednisolone were among the corticosteroids (steroid hormones produced in the adrenal cortex or made synthetically) widely used by doctors during the SARS epidemic. High-dosage patients experienced bone tissue death, diabetes, psychosis and other chronic conditions," he said.

In January, a clinical guideline released by the WHO advised against the routine administering of corticosteroids to treat viral pneumonia and ARDS－two conditions caused by COVID-19. The advice was based on studies of the drugs' long-term side effects on SARS patients. However, the guideline also stressed that studies had notable design flaws and should be treated with a degree of skepticism.

The Beijing orthopedist said: "I believe that when pulling critically ill patients away from death's door, all options should be on the table, including dexamethasone, which is a cheap and accessible drug. The key is administering it with extreme care and caution."

In China, the national guideline on COVID-19 care states that patients can receive three to five days of treatment with corticosteroids based on their symptoms, but the daily dosage cannot exceed 1 milligram to 2 milligrams per kilogram of body weight. Meanwhile, the immunosuppressive effect and delayed viral clearance－the time in which a virus can no longer be detected in blood tests－caused by the steroids must be accounted for.

In an open letter published in The Lancet in late February, five Chinese doctors said the benefits and harm caused by using corticosteroids must be considered carefully. Dosage should be low-to-moderate, and the duration must be less than seven days.