Which statement about methotrexate and pulmonary toxicity is true?

• A. It never causes respiratory effects
• B. It can cause pulmonary fibrosis
• C. It has no pulmonary effects
• D. It only causes skin toxicity

Answer: (B)

Methotrexate can cause pulmonary toxicity, including pulmonary fibrosis. This drug can trigger an inflammatory reaction in the lungs (methotrexate-induced pneumonitis) that may progress to fibrosis if exposure continues or the reaction isn’t promptly addressed. Patients often develop cough, shortness of breath, fever, and hypoxemia, usually within weeks to months of starting therapy. Imaging may show diffuse interstitial infiltrates and lung function tests often reveal a restrictive pattern. Management involves stopping methotrexate and, in many cases, administering corticosteroids; re-exposure is generally avoided because of the risk of recurrence and worsening lung injury.

The other statements are not correct because methotrexate can indeed cause respiratory effects, and it is not limited to skin toxicity.