Its main side effects are gastrointestinal upset (vomiting, diarrhea, stomach cramps), skin rash, headache, dizziness, and ocular toxicity. However, serious side effects including arrhythmia, bronchospasm, angioedema, and seizures can rarely occur.
Serious side effects
muscle weakness, cramps, stiffness or spasms, or changes in how your skin feels such as tingling. frequent infections with a high temperature, sore throat or mouth ulcers. bruising that happens more easily than usual.
Common side effects occur in one percent to less than 10 percent of people. Uncommon side effects occur in 0.1 percent to less than one percent of people. Rare side effects occur in 0.01 percent to less than 0.1 percent of people. Very rare side effects occur in less than 0.01 percent of people.
Cardiomyopathy and QT Prolongation
Long-term use and high doses of hydroxychloroquine are risk factors for the development of cardiomyopathy.
Hydroxychloroquine may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.
This medicine may cause muscle and nerve problems. Check with your doctor right away if you have muscle weakness, pain, or tenderness while using this medicine. Hydroxychloroquine may cause some people to be agitated, irritable, or display other abnormal behaviors.
Keep taking hydroxychloroquine until your doctor tells you to stop. Do not stop taking it just because you feel better. If you stop, your symptoms may get worse again.
How does hydroxychloroquine work? Hydroxychloroquine is a disease-modifying anti-rheumatic drug (DMARD). 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.
Hydroxychloroquine may potentially result in adverse effects on the central nervous system, mainly irritability, nervousness, emotional changes, nightmares, and even true psychoses [3, 4].
The study found that a person who decreases her/his HCQ dose is 54% more likely to experience a flare sooner than someone who maintains the same dose. And, if someone stops taking the medication entirely, she/he is 61% more likely to have a flare sooner than someone who continues on HCQ.
Hydroxychloroquine acts by suppressing Toll-like receptors to trigger important immunomodulatory effects. Hydroxychloroquine is a well-established and effective therapy for systemic and cutaneous lupus and other autoimmune diseases.
Adults—At first, 400 to 600 milligrams (mg) taken as a single dose or in two divided doses per day. Then, 200 mg once a day or 400 mg taken as a single dose or in two divided doses per day. Your doctor may adjust your dose if needed. Children—Use and dose must be determined by your doctor.
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. Unfortunately, once they lose a severe amount of vision loss, it is permanent.
Can Plaquenil have effects on my teeth? No, side effects related to teeth weren't reported in Plaquenil's clinical studies.
Another is hydroxychloroquine (Plaquenil) which can also cause sleep difficulties. Your doctor may recommend you take these medications early in the day to try and reduce the impact on your sleep. You may still experience sleep problems even if your PsA is under control.
There's no known interaction between alcohol and hydroxychloroquine. However, if you're also taking methotrexate you should keep well within the recommended limits (no more than 14 units of alcohol per week for adults) as methotrexate can interact with alcohol and affect your liver.
This medication may irritate the stomach, and should be taken with food. It is best to avoid coffee, spicy food or alcohol.
In some people, HCQ may cause gastrointestinal problems, such as nausea, vomiting, upset stomach, cramps, or diarrhea. These may occur for the first few days a person takes the drug while the body adjusts to the medication.
Patients usually complain of difficulty in reading, decreased vision, missing central vision, glare, blurred vision, light flashes, and metamorphopsia.
Once you and your doctor are sure the drug works for you, do not stop taking hydroxychloroquine without talking to your doctor. Symptoms of rheumatoid arthritis will return if you stop taking hydroxychloroquine.
Methotrexate is widely regarded as one of the safest of all arthritis drugs, though it carries some potential downsides.
Methotrexate is a common treatment for some types of cancer, rheumatoid arthritis, and psoriasis, but it can have many side effects. Hydroxychloroquine (Plaquenil) is an effective medication for autoimmune conditions (such as rheumatoid arthritis and lupus) and certain types of malaria.
The usual dose is between one and two tablets per day (200 to 400 mg per day). If you are taking two tablets a day you can take them all at once or divide them up: one in the morning and one in the evening. The maximum amount of HCQ you can take is based on your body weight.