Chloroquine and hydroxychloroquine (HCQ) are commonly used antimalarial agents as the treatment for a wide range of autoimmune disorders including dermatological, rheumatoid, and connective tissue diseases. These amphiphilic drugs can cause toxic myopathy in in patients which are commonly characterized as reversible proximal muscle weakness, dysphagia and dyspnea. Herein, we report a case of a patient on HCQ, who suffered from toxic myopathy presenting as proximal muscle weakness and dysarthria, which was fully recovered after the cessation.

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a neuroinflammatory disease mediated by autoantibodies against the NMDAR, typically presenting with psychiatric symptoms, cognitive dysfunction, and motor dysfunction. These neuropsychiatric symptoms may be mimicked by drug abuse, and the development of anti-NMDAR encephalitis may be triggered by certain substance use. Here we report a case of anti-NMDAR encephalitis who developed neuropsychiatric symptoms after illicit substance use, the first report in Korea.