Article shared from the American Academy of Ophthalmology
May. 15, 2020
Some physicians are using the malaria drugs Plaquenil (hydroxychloroquine) and Aralen (chloroquine) as a potential treatment for coronavirus (COVID-19). As studies continue on the use of these drugs for COVID-19, patients should be aware of the drugs’ possible side effects, including eye problems.
What are hydroxychloroquine and chloroquine?
- These medicines, taken as pills, have been used for decades to treat malaria.
- Hydroxychloroquine is also prescribed for rheumatoid arthritis, systemic lupus erythematosus and other autoimmune disorders.
- The US Food and Drug Administration approved these drugs for the emergency treatment of coronavirus disease.
Why use malaria drugs to treat coronavirus?
These drugs may help stop the immune system from going overboard in its attack on the virus. Some patients with severe COVID-19 have experienced organ failure and death, apparently because their immune system kept attacking long after the virus was defeated. Hydroxychloroquine helps calm the immune response. That’s why it works so well for autoimmune conditions like lupus. Physicians hope this may help with COVID as well.
Doctors are not sure what dose is best for patients with COVID-19. For now, the drugs are being prescribed at a higher dose and for a shorter period of time for COVID-19 than for other conditions.
But it is not yet clear how well hydroxychloroquine and chloroquine work in patients with COVID-19. The drugs appear to protect laboratory-grown cells from coronavirus, but scientists are only beginning to test the drugs for this condition in human clinical trials. And there are reports of heart problems among people who are taking these drugs for treatment of COVID-19.
Are hydroxychloroquine and chloroquine safe?
When used to treat health conditions other than COVID-19, hydroxychloroquine and chloroquine are generally considered safe for most people. Side effects may include stomach pain, nausea, vomiting, headache and sometimes itchiness.
However, these drugs can cause health complications, including retinal damage, in some people. Also, people with psoriasis, heart arrhythmia, kidney disease or liver disease may be at risk of complications from the drugs.
As the COVID-19 pandemic continues, there are reports of abnormal heart rhythms in coronavirus patients who are treated with hydroxychloroquine and chloroquine. This heart problem is seen often when these drugs are given in combination with azithromycin or other medicines.
Will these drugs damage my retina?
Patients who rely on these drugs to treat autoimmune conditions such as lupus rarely experience eye damage. Only about 1% to 2% of patients develop retinal problems during a 5-year course of treatment.
“But COVID-19 patients are being given roughly double this dosage, though for only 1-2 weeks,” says ophthalmologist and Academy spokesperson William F. Mieler, MD. “We don’t yet know for sure what this higher dosage will do to the eyes, as well as to the rest of the body.”
There are certain conditions that may make people more prone to retinal damage from hydroxychloroquine and chloroquine. Patients with the highest risk tend to be older than 50, have a history of a retinal disease such as macular degeneration or have previously taken tamoxifen for breast cancer.
What are the signs of retinal toxicity?
Patients who develop retinal damage from hydroxychloroquine and chloroquine may not notice changes in their vision at first. As the damage worsens, symptoms may include:
- Trouble focusing on objects straight ahead, due to loss of central vision
- Difficulty reading
- Weak, blurry or distorted vision
- Changes in color vision
If you notice any visual changes during or after taking these drugs, call your ophthalmologist right away.