Strong suspicion of lung toxicity due to riluzole

Riluzole is a drug used in the treatment of amyotrophic lateral sclerosis. To date, reports of lung toxicity have been exceptional. We present the case of a 74-year-old man diagnosed with amyotrophic lateral sclerosis. Following 3,5 months of treatment with riluzole (Rilutek(R)), the patient began to present a clinical picture consisting of nonproductive cough, progressive dyspnea (even with slight exertion), weakness, and radiologic progression with the appearance of predominantly peripheral bilateral pulmonary infiltrates that did not respond to treatment with amoxicillin-clavulanic acid. Bacterial tests did not reveal the presence of germs, nor did other examinations suggest an alternative diagnosis. The patient did not resume treatment with the drug or undergo complementary procedures aimed at obtaining histologic samples. Nevertheless, the coincidence in time, lack of response to antibiotic treatment, remission of symptoms following withdrawal of the drug without initiating any other treatment except 40 mg/d of methylprednisolone for 6 days, absence of alternative diagnoses, and suggestive clinical and radiologic findings all together point to toxicity due to riluzole.