warnings and cautions
5. WARNINGS AND PRECAUTIONS Cardiomyopathy and Ventricular Arrhythmias: Fatal or life-threatening cardiomyopathy and ventricular arrhythmias were reported. ( 5.1 ) Retinal Toxicity: Irreversible retinal damage is related to cumulative dosage and treatment duration. Baseline retinal exam and exams during treatment are recommended. ( 5.2 ) Serious Skin Reactions: Stevens Johnson syndrome, toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms, acute generalized exanthematous pustulosis have been reported. ( 5.3 ) Worsening of Psoriasis and Porphyria: Avoid in patients with psoriasis or porphyria. ( 5.4 ) Hematologic Toxicity: Discontinue if myelosuppression occurs. ( 5.5 ) 5.1 Cardiomyopathy and Ventricular Arrhythmias Fatal and life-threatening cases of cardiotoxicity, including cardiomyopathy, have been reported in patients treated with hydroxychloroquine sulfate. Signs and symptoms of cardiac compromise have occurred during acute and chronic hydroxychloroquine sulfate treatment. Patients may present with ventricular hypertrophy, pulmonary hypertension and conduction disorders including sick sinus syndrome. ECG findings include atrioventricular, right or left bundle branch block. Hydroxychloroquine sulfate has a potential to prolong the QT interval. Ventricular arrhythmias (including torsades de pointes) have been reported in hydroxychloroquine sulfate-treated patients. The magnitude of QT prolongation may increase with increasing concentrations of the drug. Therefore, the recommended dose should not be exceeded [see Adverse Reactions ( 6 ) , Overdosage ( 10 )]. Avoid hydroxychloroquine sulfate administration in patients with congenital or documented acquired QT prolongation and/or known risk factors for prolongation of the QT interval such as: Cardiac disease, e.g., heart failure, myocardial infarction. Proarrhythmic conditions, e.g., bradycardia (< 50 bpm). History of ventricular dysrhythmias Uncorrected hypokalemia and/or hypomagnesemia. Concomitant administration with QT interval prolonging agents [see Drug Interactions ( 7.1 )] as this may lead to an increased risk for ventricular arrhythmias. Therefore, hydroxychloroquine sulfate is not recommended in patients taking other drugs that have the potential to prolong the QT interval. Monitor cardiac function as clinically indicated during Hydroxychloroquine sulfate therapy. Correct electrolyte imbalances prior to use. Discontinue hydroxychloroquine sulfate if cardiotoxicity is suspected. 5.2 Retinal Toxicity Irreversible retinal damage was observed in some patients treated with hydroxychloroquine sulfate and it is related to cumulative dosage and treatment duration. In patients of Asian descent, retinal toxicity may first be noticed outside the macula. Risk factors for retinal damage include daily hydroxychloroquine sulfate dosages ≥5 mg/kg of actual body weight, durations of use greater than five years, renal impairment, use of concomitant drug products such as tamoxifen citrate, and concurrent macular disease. Within the first year of starting hydroxychloroquine sulfate, a baseline ocular examination is recommended including best corrected distance visual acuity (BCVA), an automated threshold visual field (VF) of the central 10 degrees (with retesting if an abnormality is noted), and spectral domain ocular coherence tomography (SD-OCT). For patients at higher risk of retinal damage, monitoring should include annual examinations which include BCVA, VF and SD-OCT. For patients without significant risk factors, annual retinal exams can usually be deferred until five years of treatment. In patients of Asian descent, it is recommended that visual field testing be performed in the central 24 degrees instead of the central 10 degrees. If ocular toxicity is suspected, discontinue hydroxychloroquine sulfate and monitor the patient closely given that retinal changes and visual disturbances may progress even after cessation of therapy. 5.3 Serious Skin Reactions Serious adverse reactions have been reported with the use of hydroxychloroquine sulfate including Stevens- Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS syndrome), acute generalized exanthematous pustulosis (AGEP). Monitor for serious skin reactions, especially in patients receiving a drug that may also induce dermatitis. Advise patients to seek medical attention promptly if they experience signs and symptoms of serious skin reactions such as blisters on the skin, eyes, lips or in the mouth, itching or burning, with or without fever [see Warnings and Precautions ( 5.4 ), Adverse Reactions ( 6 )]. Discontinue hydroxychloroquine sulfate if these severe reactions occur. 5.4 Worsening of Psoriasis and Porphyria Administration of hydroxychloroquine sulfate in patients with psoriasis may precipitate a severe flare-up of psoriasis. Administration of hydroxychloroquine sulfate in patients with porphyria may exacerbate porphyria. Avoid hydroxychloroquine sulfate in patients with psoriasis or porphyria, unless the benefit to the patient outweighs the possible risk. 5.5 Hematologic Toxicity Hydroxychloroquine sulfate may cause myelosuppression including aplastic anemia, agranulocytosis, leukopenia, or thrombocytopenia. Monitor blood cell counts periodically in patients on prolonged hydroxychloroquine sulfate therapy. If the patient develops myelosuppression which cannot be attributable to the disease, discontinue the drug. 5.6 Hemolytic Anemia Associated with G6PD Deficiency Hemolysis has been reported in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Monitor for hemolytic anemia as this can occur, particularly in association with other drugs that cause hemolysis. 5.7 Skeletal Muscle Myopathy or Neuropathy Skeletal muscle myopathy or neuropathy leading to progressive weakness and atrophy of proximal muscle groups, depressed tendon reflexes, and abnormal nerve conduction, have been reported. Muscle and nerve biopsies have demonstrated bodies and muscle fiber atrophy with vacuolar changes. Assess muscle strength and deep tendon reflexes periodically in patients on long-term therapy with hydroxychloroquine sulfate. If weakness occurs, discontinue the drug. 5.8 Neuropsychiatric Reactions Including Suicidality Suicidal behavior has been reported in patients treated with hydroxychloroquine sulfate [see Adverse Reactions ( 6 )]. Alert patients to contact their healthcare provider if they experience new or worsening depression, suicidal thoughts or behavior, or mood changes. The risk and benefit of continued treatment with hydroxychloroquine sulfate should be assessed for patients who develop these symptoms. 5.9 Hypoglycemia Hydroxychloroquine sulfate can cause severe and potentially life-threatening hypoglycemia, in the presence or absence of antidiabetic agents [see Drug Interactions ( 7 )]. Measure blood glucose in patients presenting with clinical symptoms suggestive of hypoglycemia and as adjust the antidiabetic treatment as necessary. Warn hydroxychloroquine sulfate-treated patients about the risk of hypoglycemia and educate them on the signs and symptoms of hypoglycemia; diabetic patients should monitor their blood sugar levels. Advise patients to seek medical attention if they develop any signs and symptoms of hypoglycemia.