A Fatal Case of Drug-Induced Lung Injury Potentially Related to Olanzapine

Drug-induced lung injury (DILI) occurs when exposure to a drug leads to inflammation and, eventually, fibrosis of the lung interstitium. While DILI is a rare side effect of antipsychotic medication, once it manifests, it requires detailed investigation and prompt treatment. Diagnosing DILI can be challenging at times due to its similarity to conditions such as infectious diseases or interstitial pneumonia induced by other causes. We hereby report a fatal case of suspected DILI associated with olanzapine. A 61-year-old female with a history of delusional disorder was admitted to our hospital due to worsened psychiatric symptoms. Ten milligrams of olanzapine had been initiated a week prior to admission by a psychiatrist at the local clinic to control these symptoms. After admission, although the patient claimed no respiratory symptoms, she developed a slight fever and deterioration of chest radiologic findings. Bronchoalveolar lavage revealed a progressively bloody return of fluid, suggesting pulmonary alveolar hemorrhage. Since no respiratory disorders have been noted, and considering the exclusion of other potential diagnoses, DILI was strongly suspected. Although olanzapine was promptly discontinued, the patient's condition rapidly deteriorated. Despite high-dose steroid therapy, the patient's response to treatment was inadequate, and she finally succumbed to the illness. This case highlights that olanzapine may induce lung injury similar to other psychiatric drugs. Furthermore, early diagnosis and treatment are essential for patients with psychiatric disorders who may sometimes present with fewer symptoms.