Abstract
Hydrochlorothiazide (HCTZ) is a commonly used diuretic antihypertensive drug that can cause electrolyte disorders, hyperglycemia and hyperuricemia as well as rare life-threatening adverse drug reactions. These include non-cardiogenic pulmonary edema, interstitial pneumonia, angioedema and aplastic anemia. The present report describes a case of a 59-year-old man who developed a hypersensitivity reaction to HCTZ. Specifically, the patient presented with symptoms of cough, chest tightness and shortness of breath, with pneumonic consolidation on chest CT and elevated levels of white blood cell count, neutrophil percentage, C-reactive protein and procalcitonin. A presumptive diagnosis of severe pneumonia was made initially. However, during the gradual recovery of the patient through treatment, he mistakenly ingested HCTZ containing losartan potassium intended for another patient, which resulted in symptoms similar to those observed upon admission. Upon further inquiry into the medical history, it was revealed that the patient had also taken irbesartan/HCTZ 4 h prior to hospitalization. There was no evidence of a pathogenic infection. Therefore, HCTZ-induced anaphylactic reaction was considered to be the most likely etiology for his severe shock. Treatments including epinephrine, methylprednisolone and respiratory support were administered. After 7 days, the patient was transferred from the Respiratory Intensive Care Unit [The Affiliated Jiangning Hospital of Nanjing Medical University (Nanjing, China)] to a general ward. During the follow-up, 12 months after advising the patient to discontinue HCTZ, there had been no recurrence of the aforementioned symptoms. At the time of publication, the patient is currently alive.