A Brazilian medical trial of a drug that has been stockpiled by Israel as a potential treatment for COVID-19 has been stopped due to patients developing irregular heartbeats that can cause a fatal heart attack. Another trial in Sweden was halted when patients reported migraines, peripheral vision loss and cramps.
Chloroquine and a newer, similar drug called hydroxychloroquine, have been pushed by US President Donald Trump after some very small, early tests suggested the drugs might curb the virus from entering cells. But the drugs, both used in the treatment of malaria, have long been known to have potentially serious side effects, including altering the heartbeat in a way that could lead to sudden death.
The Brazilian study, in the Amazonian city of Manaus, had planned to enroll 440 severely ill COVID-19 patients to test two doses of chloroquine, but researchers reported results after only 81 had been treated.
One-fourth of those assigned to get 600 milligrams twice a day for 10 days developed heart rhythm problems, and trends suggested more deaths were occurring in that group, so scientists stopped that part of the study.
The other group was given 450 milligrams twice a day on the first day then once a day for four more days. That is closer to what’s being tried in some other studies including some in the United States. It’s too soon to know whether that will prove safe or effective; the Brazil study had no control group that was getting no treatment.
Only one participant in the Brazil study had no signs of the virus in throat swabs after treatment, researchers noted.
The results from the Brazil study were posted on a research website and have not yet been reviewed by other scientists.
Complicating matters is that all patients in the study also received two antibiotics, ceftriaxone and azithromycin. The latter also can have effects on the heart. Trump has touted the hydroxychloroquine-azithromycin combination.
A French Doctor, Didier Raoult, has said he conducted a study of 80 patients that showed that four out of five of those treated with the drug had “favorable” outcomes.
He had earlier reported that after treating 24 patients for six days with hydroxychloroquine and azithromycin, the virus disappeared in all but a quarter of them.
The research has not been peer reviewed nor formally published in a medical journal.
French President Emmanuel Macron met Raoult and his team in Marseilles a week ago to discuss their latest findings, though the president did not comment publicly on the meeting afterward.
Speaking to the financial daily Globes on Thursday, Prof. Ronni Gamzu, a former director general of the Health Ministry who now heads the Ichilov Hospital in Tel Aviv, said the hospital had used chloroquine, but had seen no evidence of its efficacy in treating COVID-19.
“We used chloroquine in the hospital and we did not get the impression that it is effective, and that is also the opinion of scientists today. I am currently following developments closely and I don’t see any special news about a treatment in development,” Gamzu told Globes.
Israel has stockpiled both chloroquine and hydroxychloroquine on the assumption that if trials find that it is beneficial in the treatment of COVID-19 this would spark a buying war for the drugs.
Speaking to The Times of Israel last week with regard to chloroquine, Jacob Moran-Gilad, a member of the Health Ministry’s Epidemic Management Team, said, “In a few weeks’ time if there is official data to show it is beneficial it will be very difficult to secure the drug.”
Moran-Gilad said that the Epidemic Management Team discussed whether to give hospitals any directions regarding hydroxychloroquine, and decided not to. “At the moment there is no official guidance or endorsement by the Health Ministry that it should be used for COVID-19,” he said. “We discussed this in the national management team and we decided not to give guidance as there is no data to support the use of this drug.”
He said that doctors are allowed to prescribe hydroxychloroquine to their patients, and some are doing so. But he stressed: “The fact there is a stockpile of the drug does not mean there is official endorsement or encouragement to liberally use this drug.”
Nathan Jeffay contributed to this report.