Methotrexate Lung Toxicity: Signs, Risks, and What to Do

When you take methotrexate, a common immunosuppressant used for rheumatoid arthritis, psoriasis, and some cancers. Also known as MTX, it works by slowing down overactive immune cells—but sometimes, it can accidentally damage the lungs. This isn’t common, but when it happens, it’s serious. interstitial lung disease, a group of disorders that cause scarring and inflammation in the lung tissue is the most frequent form of methotrexate lung toxicity. It doesn’t always show up right away. Some people notice symptoms after a few months; others don’t feel anything until after a year or more.

What does it feel like? Think of it as a slow-burning cough that won’t quit, shortness of breath when you climb stairs, or feeling tired even after a full night’s sleep. These aren’t just signs of getting older or a cold—they can be your lungs telling you something’s wrong. People on higher doses, those with existing lung conditions like COPD, or those who smoke are at greater risk. But it can happen to anyone, even if they’ve been on methotrexate for years without issues. Doctors usually catch it early by ordering chest X-rays or CT scans if symptoms appear. Blood tests alone won’t show it—you need imaging to see the actual lung changes.

drug-induced lung injury, a broad term covering lung damage caused by medications isn’t unique to methotrexate. Other drugs like amiodarone, nitrofurantoin, and some chemotherapy agents can do the same thing. But methotrexate is one of the most common culprits in autoimmune disease patients. The good news? If caught early, stopping the drug often lets the lungs heal. In some cases, doctors add corticosteroids like prednisone to reduce inflammation faster. But if it’s missed and scarring sets in, the damage can be permanent.

You won’t find this warning on every pill bottle. That’s why knowing your body matters. If you’re on methotrexate and start having unexplained breathing trouble, don’t wait. Talk to your doctor. Get checked. It’s not about fear—it’s about staying ahead. The posts below cover real cases, monitoring tips, how to tell the difference between infection and toxicity, and what alternatives exist if methotrexate becomes too risky. You’re not alone in this. Many people manage their condition safely for years. But knowing the signs could make all the difference.