Hydroxychloroquine-Induced Hypoglycemia in a Non-Diabetic Patient with Chronic Kidney Disease and Rheumatoid Arthritis.

Hydroxychloroquine (HCQ) is an immunomodulatory medication commonly used to treat several autoimmune diseases. Due to its tendency to change insulin metabolism by increasing production and reducing clearance, HCQ can cause hypoglycemia in patients with or without diabetes, albeit this is rare. There is documented evidence of HCQ-induced hypoglycemia in the literature. However, none to our knowledge has reported this adverse effect in a patient with chronic kidney disease not undergoing dialysis. We describe the case of an 81-year-old woman who went to the emergency room for care after experiencing abrupt dizziness and unconsciousness. Pertinent history includes four prior episodes of hypoglycemia after the recent initiation of HCQ for rheumatoid arthritis. Fasting glucose was <40 mg/dL on presentation. Given the appearance of symptoms after the initiation of the medication and the absence of symptoms with normal glucose upon discontinuation, it was concluded that HCQ was the likely culprit for the recurrent episodes of hypoglycemia. Physicians should be aware of this rare but possible adverse effect of HCQ, especially in older patients and patients with chronic kidney disease. Prompt elimination of the medication can reduce the risk of some of the devastating consequences of hypoglycemia.