French pharmaceutical giant Sanofi has warned Irish medical professionals about potential heart problems for coronavirus patients treated with a drug it developed.
In a safety notice published over the weekend, it said there had been a recent increase in serious and life-threatening cardiac issues among patients who had been given hydroxychloroquine – in most cases with other drugs, such as azithromycin. Sanofi said there had been a number of sudden deaths associated with the treatment.
The drug leaped to prominence when US president Donald Trump touted it as a potential miracle cure for the virus. His comments followed a small French trial of the combination therapy of hydroxychloroquine and azithromycin – a drug more commonly used to treat bacterial infections – that found it had been effective in treating Chinese Covid-19 patients.
However, that trial has since come in for strong criticism over its failure to meet standard criteria for clinical trials.
Sanofi originally developed the drug in the 1950s. It has long been widely used to treat malaria as well as lupus, rheumatoid arthritis and certain skin conditions that are aggravated by sunlight.
Patent protection for the medicine expired decades ago and it is now produced in generic form by many companies.
Irregular heartbeat
In its warning, issued with the approval of the the Health Products Regulatory Authority, which regulates medicine and medical devices in the Irish market, Sanofi urged doctors to use caution in any decision to prescribe the drug to treat Covid-19 patients, especially in patients at risk of irregular heartbeat.
The French group stressed that hydroxychloroquine “has no marketing authorisation for the management of Covid-19 anywhere in the world and, therefore, prescription of hydroxychloroquine for this purpose, outside the context of a clinical trial, is off-label”.
Off-label refers to the practice of doctors prescribing a medicine for a condition other that what it is licensed for in that market.
“To date,” Sanofi said, “there is insufficient clinical evidence to draw any conclusion over the clinical efficacy and safety of hydroxychloroquine in the management of Covid-19, whether it is used as a single agent or in combination with any other medicines such as azithromycin.”
