Hydroxychloroquine is generally well-tolerated in most patients, with the majority of adverse effects being mild and transient. plaquenil sale However, rare but serious adverse reactions, such as cardiomyopathy or neuropsychiatric effects, may occur with prolonged use or high doses of the medication. Patients should be educated about potential warning signs and instructed to seek medical attention if they experience symptoms such as chest pain, palpitations, or mood changes.