Hydroxychloroquine (Plaquenil) and chloroquine cause ocular toxicity to various parts of the eye such as the cornea, ciliary body, and retina. Chloroquine can also induce cataract formation; however, no reports of hydroxychloroquine and cataract have been reported.
Early detection of any problems is key. If you notice a change in your central or color vision or have trouble seeing at night, promptly schedule an evaluation with your eye doctor. Regular use of an Amsler grid is recommended as well.
If your ophthalmologist finds any signs of retinal damage, they will tell your primary care doctor or inflammatory disease specialist to stop Plaquenil treatment immediately. This will help you avoid central vision loss. Unfortunately, vision loss from Plaquenil is not reversible.
Patients usually complain of difficulty in reading, decreased vision, missing central vision, glare, blurred vision, light flashes, and metamorphopsia. They can also be asymptomatic. Most patients have a bull's eye fundoscopic appearance.
“If you feel like your central vision is getting blurred, if you lose the ability to see a digital clock, if you lose color vision—if reds look kind of washed out—or if you have trouble seeing at night: Those are early signs that you might be developing Plaquenil retinopathy,” says Katz.
Avoid taking an antacid or Kaopectate (kaolin-pectin) within 4 hours before or 4 hours after you take hydroxychloroquine.
Nausea, vomiting, and diarrhea are the most common side effects of hydroxychloroquine. And some people may also experience stomach pain.
Using Plaquenil for a long period of time may harm the retina, causing serious vision loss. People with retinal damage from Plaquenil are not aware at first that they are losing vision.
Weight gain or weight loss
For some people, Plaquenil may cause weight loss. This is because the drug can decrease your appetite, which may lead to the weight loss. But it's not known how many people have had weight loss while taking Plaquenil. Weight gain, on the other hand, isn't a known side effect of Plaquenil.
Dooley says, “Many immunosuppressants must be taken as two doses per day, with at least eight hours between. If you're late taking a morning dose, you should still take the second dose at the right time.” Dooley says time of day also matters less with Plaquenil® (hydroxychloroquine). But, it's best taken with food.
Patients starting treatment with Plaquenil should have a baseline eye examination within the first year of taking this medication and then regular screenings thereafter; every six months or yearly as advised by your eye doctor.
Hydroxychloroquine may potentially result in adverse effects on the central nervous system, mainly irritability, nervousness, emotional changes, nightmares, and even true psychoses [3, 4].
Taking high doses (600 mg per day) of hydroxychloroquine over a long time (more than five years) can also cause damage to your retina, the light-sensitive coating at the back of your eye.
Plaquenil and other anti-malarials are the key to controlling lupus long term, and some lupus patients may be on Plaquenil for the rest of their lives. For this reason, you can think of anti-malarials as a sort of “lupus life insurance.”
Hydroxychloroquine is a disease-modifying anti-rheumatic drug (DMARD). It regulates the activity of the immune system, which may be overactive in some conditions. Hydroxychloroquine can modify the underlying disease process, rather than simply treating the symptoms.
Long-term use and high doses of hydroxychloroquine are risk factors for the development of cardiomyopathy. Cardiac failure, conduction disorders (including QT prolongation and Torsades de Pointes) and sudden cardiac death are consequences of the cardiomyopathy.
Plaquenil and alcohol
Plaquenil isn't known to interact with alcohol. However, certain side effects from Plaquenil could be worsened by drinking alcohol. Examples of these side effects include headache, nausea, and dizziness. (For information about Plaquenil's side effects, see this article.)
These may occur for the first few days a person takes the drug while the body adjusts to the medication. Loss of appetite, tiredness, weakness, or headache are uncommon side effects and typically go away over time.
After patients respond well to the medication, medical providers will reduce the dose to 200 to 400 mg once daily or divided into two doses. This is a maintenance dose. The dose shouldn't exceed 600 mg or 6.5 mg per kilogram of body weight, whichever is lower.
However, some of the medications commonly used to treat RA – including hydroxychloroquine (Plaquenil), methotrexate and nonsteroidal anti-inflammatory drugs (NSAIDs) such as naproxen (Naprosyn) or celecoxib (Celebrex) – can cause reactions such as rashes or sunburn with ultraviolet (UV) light exposure.
It works by calming your immune system. This helps reduce swelling (inflammation) in people with autoimmune conditions, where your immune system attacks your own body. For example, it helps reduce the inflammation that causes swollen and stiff joints in rheumatoid arthritis.
It's possible for hydroxychloroquine to cause liver problems. Liver problems weren't reported in clinical trials of the drug. However, liver problems were reported in people taking hydroxychloroquine after the drug was approved for use.