EMA is reminding healthcare professionals to closely monitor patients with COVID-19 who are receiving chloroquine or hydroxychloroquine, given the serious side effects that can result from treatment with these medicines.
Both chloroquine and hydroxychloroquine, which are authorised for malaria and certain autoimmune diseases, have been used to treat patients with COVID-19 but their beneficial effects in this patient population are not established.
Several observational studies in COVID-19 have reported that chloroquine and hydroxychloroquine are associated with an increased risk of heart problems, a well-known side effect of such treatments, including cardiac arrhythmias and cardiac arrest.
When prescribing these medicines, healthcare professionals should take into account pre-existing heart conditions, uncorrected potassium or magnesium imbalance, and concomitant use with medicines that prolong the QT interval as these factors may make patients more prone to heart rhythm disorders.
Healthcare professionals should also note that heart rhythm disorders may be more likely or be more severe if chloroquine or hydroxychloroquine are used at higher doses than those recommended for their authorised indications or if they are combined with certain antibiotics such as azithromycin.
In addition to their effects on the heart, these medicines may cause neuropsychiatric disorders, including agitation, insomnia, confusion, psychosis and suicidal ideation. These medicines are also known to affect the liver, cause neuronal damage that can lead to seizures (fits), and lower blood sugar.
In view of the emerging data, some EU countries have suspended or stopped clinical trials investigating chloroquine and hydroxychloroquine in COVID-19 patients. For some trials, including WHO’s large multinational Solidarity trial, enrolment of patients to trial arms with these medicines has been suspended. A preliminary review of the Recovery trial, a large ongoing study on COVID-19 patients, did not identify reasons to suspend or stop the trial.
Patients who have been prescribed chloroquine or hydroxychloroquine for authorised indications (malaria and certain autoimmune diseases such as rheumatoid arthritis and lupus) should continue to take their medicines as advised by their doctor.