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.
Chloroquine (CQ) and hydroxychloroquine (HCQ) have been associated with muscle toxicity, mostly described as a proximal myopathy with evidence of lysosomal dysfunction on muscle biopsy.
Serious side effects
muscle weakness, cramps, stiffness or spasms, or changes in how your skin feels such as tingling.
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.
Hydroxychloroquine myopathy presents with proximal muscle weakness and normal to mildly elevated creatine kinase levels. There are very few reported cases of ventilatory failure due to HCQ myopathy (2, 3).
Muscle weakness
In rare cases, hydroxychloroquine can cause nerve damage that leads to muscle weakness. While the estimates vary, some studies say that this can occur in up to about 13% of people receiving long-term treatment with hydroxychloroquine.
Myopathy seen in hydroxychloroquine toxicity is thought to be due to the inhibition of lysosomal degradation of phospholipids and glycogen leading to the formation of curvilinear body seen on muscle biopsies. Hydroxychloroquine promotes the accumulation of autophagic vacuoles by inhibiting the lysosome acidification.
The early signs of hydroxychloroquine toxicity are macular edema and/or bilateral granular depigmentation of the RPE in the macula. With continued exposure to the drug, this can progress to an atrophic bullseye maculopathy with concentric rings of hypopigmentation and hyperpigmentation surrounding the fovea.
Nausea, vomiting, loss of appetite, diarrhea, dizziness, or headache may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly. Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects.
How long you take hydroxychloroquine for depends on why you're taking it. For some conditions, if hydroxychloroquine works for you then you may need to take it for several years, or even for the rest of your life, to control your symptoms.
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.
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.
Hydroxychloroquine starts to work gradually. For inflammatory conditions such as rheumatoid arthritis and lupus, it can take 6 to 12 weeks before you notice any benefits. It's important to keep taking hydroxychloroquine. You may not feel any different at first, but it is likely to be working.
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 may potentially result in adverse effects on the central nervous system, mainly irritability, nervousness, emotional changes, nightmares, and even true psychoses [3, 4].
It may also cause some people to have suicidal thoughts and tendencies, or to become more depressed. If you or your caregiver notice any of these side effects, tell your doctor right away. This medicine may cause hypoglycemia (low blood sugar).
Get medical help right away if you have any very serious side effects, including: severe dizziness, fainting, fast/irregular heartbeat, seizures. This medication may cause serious eye/vision problems.
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.
Hydroxychloroquine (HCQ) is an antimalarial drug with an immunomodulatory effect widely prescribed in patients with pSS reporting extraglandular manifestations, such as fatigue, arthralgia, arthritis or myalgia.
Early symptoms of Plaquenil toxicity may go unnoticed as they are mild. Patients may experience: Decreased color vision, specifically when visualizing red objects. A scotoma, or blind spot eccentric to central vision.
Patients usually complain of difficulty in reading, decreased vision, missing central vision, glare, blurred vision, light flashes, and metamorphopsia.
You should not use this medicine if you are allergic to hydroxychloroquine or chloroquine. Tell your doctor if you are pregnant or plan to become pregnant. Having malaria during pregnancy may also increase the risk of miscarriage, stillbirth, premature delivery, and low birth weight.
Including our patient, there are 10 reported cases of HCQ neuromyotoxicity. Muscle biopsy consistently reveals curvilinear bodies and muscle fiber atrophy with vacuolar changes. Most cases manifest as insidious onset proximal myopathy that may be associated with peripheral neuropathy and cardiac myotoxicity.