Note: This document contains side effect information about hydroxychloroquine. Some dosage forms listed on this page may not apply to the brand name Plaquenil.

Applies to hydroxychloroquine: oral tablets.

Side effects include:

The most common adverse reactions are nausea, vomiting, diarrhea, abdominal pain.

For Healthcare Professionals

Applies to hydroxychloroquine: compounding powder, oral tablet.

Cardiovascular

QT interval prolongation has been reported in patients with specific risk factors, which may lead to arrhythmia (torsade de pointes, ventricular tachycardia).^[Ref]

Rare (0.01% to 0.1%): Cardiomyopathy (sometimes resulting in cardiac failure; some with fatal outcome), conduction disorders (bundle branch block/atrioventricular heart block), biventricular hypertrophy

Frequency not reported: Arrhythmia (torsade de pointes, ventricular tachycardia)

Postmarketing reports: QT interval prolongation, ventricular arrhythmias, torsade de pointes^[Ref]

Ocular

Common (1% to 10%): Blurred vision (including due to disturbance of accommodation)

Uncommon (0.1% to 1%): Retinopathy (with changes in pigmentation, visual field defects), retinal changes (including paracentral, pericentral ring types, temporal scotomas, abnormal color vision), corneal changes (including edema, opacities), haloes, photophobia

Very rare (less than 0.01%): Extraocular muscle palsies

Frequency not reported: Maculopathies, macular degeneration, abnormal macular pigmentation and depigmentation (sometimes with bull's eye appearance), pallor of optic disc, optic atrophy, narrowing of retinal arterioles

Postmarketing reports: Irreversible retinopathy with retinal pigmentation changes (bull's eye appearance), visual field defects (paracentral scotomas), visual disturbances (visual acuity), maculopathies (macular degeneration), decreased dark adaptation, color vision abnormalities, corneal changes (edema, opacities), corneal deposition of drug with or without accompanying symptoms (halo around lights, photophobia, blurred vision^[Ref]

Blurred vision (temporary) and extraocular muscle palsies (reversible) were due to disturbance of accommodation, which was dose dependent and reversible.

Retinopathy appeared to be uncommon when the recommended daily dose was not exceeded. In its early form, it appeared reversible when therapy was discontinued. If allowed to develop, there was risk of progression even after treatment withdrawal.

Patients with retinal changes were asymptomatic initially or had scotomatous vision with paracentral, pericentral ring types, temporal scotomas, and abnormal color vision.

Corneal changes (including edema and opacities) have occurred from 3 weeks (infrequently) to some years after starting therapy. They were either symptomless or caused disturbances such as haloes, blurred vision, or photophobia; they may be transient and were reversible when therapy was discontinued.

Maculopathies and macular degeneration have been reported (onset ranging from 3 months to several years of exposure to this drug) and may be irreversible.^[Ref]

Gastrointestinal

Very common (10% or more): Abdominal pain, nausea

Common (1% to 10%): Diarrhea, vomiting^[Ref]

In general, abdominal pain, nausea, diarrhea, and vomiting resolved immediately when the dose was reduced or therapy was stopped.^[Ref]

Dermatologic

In general, skin rash, pruritus, pigmentation disorders in skin and mucous membranes, bleaching of hair, and alopecia resolved readily when therapy was discontinued.

AGEP had to be distinguished from psoriasis, although this drug has precipitated attacks of psoriasis. AGEP has been associated with fever and hyperleukocytosis. In general, outcome was favorable after stopping this drug.^[Ref]

Common (1% to 10%): Skin rash, pruritus, alopecia

Uncommon (0.1% to 1%): Pigmentary changes, pigmentation disorders in skin and mucous membranes, bleaching of hair

Rare (0.01% to 0.1%): Attacks of psoriasis

Very rare (less than 0.01%): Dermatitis bullous eruptions, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, drug rash with eosinophilia and systemic symptoms (DRESS) syndrome, photosensitivity, exfoliative dermatitis, acute generalized exanthematous pustulosis (AGEP)

Frequency not reported: Urticaria, angioedema

Postmarketing reports: Hair color changes^[Ref]

Metabolic

Common (1% to 10%): Anorexia

Rare (0.01% to 0.1%): Exacerbation/precipitation of porphyria

Postmarketing reports: Hypoglycemia, decreased appetite, porphyria^[Ref]

Nervous system

Common (1% to 10%): Headache

Uncommon (0.1% to 1%): Dizziness, nerve deafness, vertigo, tinnitus

Rare (0.01% to 0.1%): Seizure/convulsions, neuromyopathy

Very rare (less than 0.01%): Nystagmus, ataxia

Frequency not reported: Hearing loss

Postmarketing reports: Extrapyramidal disorders (e.g., dystonia, dyskinesia, tremor), deafness^[Ref]

Psychiatric

Common (1% to 10%): Affect/emotional lability

Uncommon (0.1% to 1%): Nervousness

Very rare (less than 0.01%): Psychosis, suicidal behavior, nightmares

Postmarketing reports: Irritability^[Ref]

Hepatic

Uncommon (0.1% to 1%): Abnormal liver function tests

Very rare (less than 0.01%): Fulminant hepatitis

Postmarketing reports: Acute/fulminant hepatic failure^[Ref]

Musculoskeletal

Uncommon (0.1% to 1%): Sensorimotor disorders

Frequency not reported: Absent/hypoactive deep tendon reflexes

Postmarketing reports: Skeletal muscle myopathy/muscle weakness/neuromyopathy (leading to progressive weakness, atrophy of proximal muscle groups), depression of tendon reflexes, abnormal nerve conduction studies^[Ref]

Myopathy has been reversible after therapy discontinuation, but recovery has taken many months.^[Ref]

Hematologic

Rare (0.01% to 0.1%): Bone-marrow failure/depression, anemia, aplastic anemia, leukopenia, thrombocytopenia

Very rare (less than 0.01%): Agranulocytosis

Postmarketing reports: Hemolysis (in glucose-6-phosphate dehydrogenase deficient patients)^[Ref]

Other

Very rare (less than 0.01%): Weight decreased/loss, fatigue/lassitude^[Ref]

Respiratory

Postmarketing reports: Bronchospasm^[Ref]

Hypersensitivity

Frequency not reported: Allergic reactions (urticaria, angioedema, bronchospasm), hypersensitivity myocarditis^[Ref]