Hydroxychloroquine Side Effects

Not all side effects for hydroxychloroquine may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to hydroxychloroquine: oral tablet

In addition to its needed effects, some unwanted effects may be caused by hydroxychloroquine. In the event that any of these side effects do occur, they may require medical attention. When this medicine is used for short periods of time, side effects usually are rare. However, when it is used for a long time and/or in high doses, side effects are more likely to occur and may be serious.

You should check with your doctor immediately if any of these side effects occur when taking hydroxychloroquine:

Less common
  • Blurred vision or any other change in vision—this side effect may also occur or get worse after you Stop taking hydroxychloroquine
  • Convulsions (seizures)
  • increased muscle weakness
  • mood or other mental changes
  • ringing or buzzing in ears or any loss of hearing
  • sore throat and fever
  • unusual bleeding or bruising
  • unusual tiredness
  • weakness
Symptoms of overdose
  • Drowsiness
  • headache
  • increased excitability

Some of the side effects that can occur with hydroxychloroquine may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common
  • Diarrhea
  • difficulty in seeing to read
  • headache
  • itching (more common in black patients)
  • loss of appetite
  • nausea or vomiting
  • stomach cramps or pain
Less common
  • Bleaching of hair or increased hair loss
  • blue-black discoloration of skin, fingernails, or inside of mouth
  • dizziness or lightheadedness
  • nervousness or restlessness
  • skin rash

For Healthcare Professionals

Applies to hydroxychloroquine: compounding powder, oral tablet


In general, although not every side effect listed in the side effects section may have been reported with the use of hydroxychloroquine, they have all been reported with the use of one or more 4-aminoquinoline compounds.


Ocular side effects have included disturbances of accommodation with symptoms of blurred vision (dose-related and reversible with treatment cessation). Corneal side effects have included transient edema, punctate to lineal opacities, decreased corneal sensitivity, corneal changes (with or without accompanying symptoms, including blurred vision, halos around lights, photophobia), and corneal deposits. Retinal (macular) side effects have included edema, atrophy, abnormal pigmentation (mild pigment stippling to a "bullseye" appearance), loss of foveal reflex, increased macular recovery time following exposure to a bright light (photostress test), and elevated retinal threshold to red light in macular, paramacular, and peripheral retinal areas. Other fundus changes have included optic disc pallor and atrophy, attenuation of retinal arterioles, fine granular pigmentary disturbances in the peripheral retina, and prominent choroidal patterns in advanced stage. Visual field defects have included pericentral or paracentral scotoma, central scotoma with decreased visual acuity, rarely field constriction, and abnormal color vision. The most common visual symptoms attributed to retinopathy are reading and vision difficulties (words, letters, or parts of objects missing), photophobia, blurred distance vision, missing or blacked out areas in the central or peripheral visual field, and light flashes and streaks. Patients with retinal changes may have visual symptoms or may be asymptomatic (with or without visual field changes). Rarely scotomatous vision or field defects may occur without obvious retinal change. A few cases of retinal changes consisting of change in retinal pigmentation (detected on periodic ophthalmologic examination) with visual field defects in some instances have been reported in patients receiving only hydroxychloroquine. A case of delayed retinopathy with vision loss starting 1 year after hydroxychloroquine discontinuation has been reported. Night vision difficulties and immediate blurred vision have been reversible with treatment cessation.

The corneal changes (fairly common) have been reversible. Corneal deposits have been reported as early as 3 weeks after the initiation of therapy.

Retinopathy appears to be dose related and has occurred within several months (rarely) to several years of daily therapy.


Gastrointestinal side effects have included diarrhea, anorexia, nausea, abdominal cramps, vomiting, and epigastric pain. A case of pigmentation of the gums has also been reported.

Nervous system

Nervous system side effects have included headache, dizziness, vertigo, tinnitus, nystagmus, nerve deafness, convulsions, and ataxia.


Psychiatric side effects have included irritability, nervousness, emotional changes, nightmares, and psychosis.


Musculoskeletal side effects have included skeletal muscle palsies, skeletal muscle myopathy, or neuromyopathy leading to progressive weakness and atrophy of proximal muscle groups which may be associated with mild sensory changes, depression of tendon reflexes, and abnormal nerve conduction. Absent or hypoactive deep tendon reflexes and extraocular muscle palsies have been reported. Neuromyotoxicity has been associated with hydroxychloroquine concurrently with worsening renal function.


Mucocutaneous hyperpigmentation over all extremities, the torso, and the hairline has been reported in an elderly man after long-term hydroxychloroquine use. Skin biopsies demonstrated sharply defined red-brown fibers in the deep dermis and the classic "banana-shaped body" associated with exogenous ochronosis.

Dermatologic side effects have included nonlight-sensitive psoriasis, bleaching of hair, alopecia, pruritus, skin and mucosal pigmentation, photosensitivity, and skin eruptions (urticarial, morbilliform, lichenoid, maculopapular, purpuric, erythema annulare centrifugum, Stevens-Johnson syndrome, acute generalized exanthematous pustulosis, and exfoliative dermatitis). A case of generalized pustular drug rash has also been reported.


Hematologic side effects have included various blood dyscrasias such as aplastic anemia, agranulocytosis, leukopenia, anemia, and thrombocytopenia. Hemolysis has been reported in individuals with glucose-6-phosphate dehydrogenase deficiency.


The causal relationship of hydroxychloroquine to cardiomyopathy has not been established.

Cardiovascular side effects have rarely included cardiomyopathy with high daily dosages.


Hepatic side effects have included isolated cases of abnormal liver function and fulminant hepatic failure.


Metabolic side effects have included weight loss and exacerbation or precipitation of porphyria.


Other side effects have included lassitude.


Hypersensitivity side effects have included allergic reactions (urticaria, angioedema, and bronchospasm) and hypersensitivity myocarditis.


Endocrine side effects have included a case report of hypoglycemia induced by hydroxychloroquine in a type II diabetic treated for polyarthritis.

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