Seizures as a rare adverse effect of chloroquine therapy in systemic lupus erythematosus patients: a case report and literature survey

Aside from corticosteroids and immunosuppressants, chloroquine is one of the fundamental pharmaceuticals used in systemic lupus erythematosus (SLE) therapy. Its mechanism of action is not entirely understood, however, scientists’ suppositions concern its pleiotropic nature, including stabilization of lysosomal enzymes, inhibition of antigen-presenting cells and T lymphocyte stimulation as well as blocking of the pro-inflammatory cytokine cascade, and photoprotection [1]. Also, it belongs to antimalarials, which are thought to be safe, well tolerated and effective in treatment of SLE and other inflammatory diseases [2–4]. According to research, antimalarials substantially reduce activity of the disease in more than 50% of patients and only 15% of patients discontinued antimalarial therapy because of side effects [5]. The most important adverse effects include irreversible retinopathy and ototoxicity, neuromuscular, gastrointestinal and hematopoietic reactions as well as hyperpigmentation and electrocardiography (ECG) changes [3]. Also, in rare cases, chloroquine can cause epileptic seizures, which is the subject of this paper.
A 49-year-old female patient had been diagnosed with SLE according to the American College of Rheumatology (ACR) criteria based on the following symptoms: arthralgia for 6 months, general weakness, raised temperature, loss of the body mass (about 10 kg in the 2 previous months), sunlight sensitivity, skin lesion of discoid lupus, leukopenia, presence of anti-nuclear antibodies (ANA) 1 : 2560 and decreased complement levels of C3 and C4. The patient started a therapy of 32 mg/day methylprednisolone, and after 2 weeks a dose of 250 mg/day chloroquine was added. Improvement of her general state, muscle strength, appetite and lessening of arthralgia were noted. Except for stomach ache, the patient did not complain about other side effects.
After one month of chloroquine therapy, with no previous history of such symptoms, the patient developed epileptic seizures lasting for 24 h. The seizures were of the complex partial type, and manifested themselves through an abnormal contact and involuntary movements of the upper limbs. The patient was rapidly admitted to the Neurological Department of the Medical University of Lodz, where computed tomography (CT) and magnetic resonance imaging (MRI) were performed (no pathological changes noticed). She also underwent an electroencephalography (EEG) examination, which showed significant...


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