Safety of Hydroxychloroquine and Chloroquine

The COVID-19 pandemic has many people searching for remedies to prevent or treat the disease. In particular, recent media coverage of clinical trials of hydroxychloroquine (brand name Plaquenil, among others) and a similar medication called chloroquine (brand name Aralen) have led some people to take these without a doctor’s prescription, or to take a higher dose than what they have been prescribed. 

In the United States, hydroxychloroquine is approved for the treatment of malaria, systemic lupus erythematosus, and rheumatoid arthritis. Chloroquine is approved for the treatment of malaria. While they can be very effective in the treatment of certain conditions, side effects and toxicity can occur at even regularly prescribed doses.  

Hydroxychloroquine and chloroquine toxicity can involve almost every organ system. Effects may include headache, vision or hearing changes, low blood potassium, and changes in heartbeat. If used without a doctor’s supervision, in combination with other medications, or by someone with underlying medical problems, side effects can include irregular heartbeat (arrhythmia), seizures, and heart failure leading to death. 

The Food and Drug Administration (FDA) recommends no one take hydroxychloroquine or chloroquine to prevent or treat COVID-19 outside of a clinical trial because of the risk of heart failure.  This medication and substances related to it (including those found in fish tank additives) should never be taken without a physician’s approval. 

If you have taken hydroxychloroquine or chloroquine and are concerned about the possibility of side effects, call your doctor or the Poison Control hotline at 1-800-222-1222.  For more information, see the Blue Ridge Poison Center’s article on hydroxychloroquine.