These 11 Medications Can Harm Your Lungs or Cause Shortness of Breath

Written by Khama Ennis, MD, MPH, FACEP | Reviewed by Sophie Vergnaud, MD Updated on August 8, 2022

Key takeaways:

• Some medication side effects lead to new lung problems or worsen preexisting lung disease.
• Some people are at higher risk than others — people with lung disease, a history of smoking, and those taking chemotherapy or rheumatological medications. 
• If you notice shortness of breath after starting a new treatment, let your provider know. You might need to stop and/or change the medication to protect your lungs. 

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Shortness of breath is not always the result of a lung disease like asthma, pneumonia, or smoking-related lung disease. Sometimes — and this may come as a surprise to you — the medications you take can cause it. 

Certain medications can lead to shortness of breath in a few different ways. They can trigger asthma symptoms or allergic reactions. In rare cases, they can cause a type of inflammation in the lung that scars its delicate tissues. This is called “drug-induced interstitial lung disease” (DIILD). 

Let’s look at the top medications that can irritate the lungs and cause shortness of breath.

11 medications that can cause shortness of breath

Different medications can cause breathing problems, so we’ll review 11 of the most common culprits. Speak to your provider if you’re taking one or more of these medications and have new breathing symptoms that another diagnosis can’t explain, like a cold, allergies, or an infection. One of your medications might be causing your breathing symptoms. 

1. Macrobid (nitrofurantoin) 

Macrobid (nitrofurantoin) is an antibiotic that often treats urinary tract infections. It has been linked to both short-term and long-term lung problems. But this reaction is rare. It affects 1% of people who take it. 

2. Amiodarone 

Amiodarone treats abnormal heart rhythms like atrial fibrillation. It’s the heart drug most commonly linked to lung problems. DIILD affects as many as 2% of people on lower doses of amiodarone. That’s why it needs careful monitoring. People recover well if they detect lung problems early and stop the medication. Sometimes treatment also includes steroids to lower inflammation.

3. NSAIDs

Aspirin and other nonsteroidal anti-inflammatory medications (NSAIDs) treat pain and inflammation. But, in rare cases, they can cause aspirin-exacerbated respiratory disease (AERD) in some people — a combination of asthma, nasal polyps, and sinus congestion. 

AERD affects 1% to 2% of the general population. In people with asthma and chronic sinus problems‚ it’s more common — up to 10%.

4. Beta blockers

Beta blockers are a common class of blood pressure and heart medications. They don’t cause DIILD, but they can cause breathing problems (sudden airway tightening or bronchospasm) in people with underlying asthma or chronic obstructive pulmonary disease (COPD). 

5. Methotrexate  

Methotrexate is a treatment for rheumatoid arthritis and psoriasis as well as other autoimmune and skin conditions. It can cause lung problems in some people who take it. But the situation can get murky.

While methotrexate can cause lung problems, so can rheumatoid arthritis and some of the other diseases that methotrexate treats. Sometimes it’s not clear if the cause of the breathing problem is methotrexate or the underlying autoimmune disorder — or both. 

6. Leflunomide 

It’s a similar situation with leflunomide, although this medication is not used as often as methotrexate. Leflunomide is a treatment for rheumatoid arthritis that can be helpful in people who don’t tolerate the side effects of methotrexate. In people with preexisting lung disease, leflunomide can make it worse in up to 5.7% of cases. But it only causes new problems in 1.2% of people who use it.  

Chemotherapy medications

Cancer treatment medications are a common cause of DIILD. Chemotherapy causes between ¼ and ½  of all DIILD cases. Chemotherapy medications are most likely to cause DIILD when you use them in combination with other medications. 

Five of the most common culprits are: 

1. Bleomycin is a medication that treats lymphoma, head and neck cancers, and cervical and testicular cancer. People with poor kidney function, especially those over 40 years old, have a higher risk of DIILD. Symptoms usually start around 4 months after beginning treatment.
2. Gemcitabine is a medication that treats pancreatic, breast, lung, and ovarian cancer. The timing is less predictable, but DIILD is more likely to occur in people getting treatment for lung cancer, especially those over 80 years old.
3. EGFR-targeted treatments include Gefitinib, for non-small cell lung cancer, and Erlotinib, for pancreatic cancer. 
4. mTOR inhibitors include temsirolimus and everolimus, which treat kidney cancer (renal cell carcinoma), and sirolimus, which reduces the risk of rejection in people receiving transplants. 
5. Busulfan is a treatment for chronic myelogenous leukemia. Providers sometimes use it before stem cell or bone marrow transplants. DIILD can affect up to 8% of people who receive busulfan. The symptoms usually begin within the first year of starting the medication.

What is drug-induced interstitial lung disease?

Drug-induced interstitial lung disease (DIILD) is a type of scarring in the lung caused by medication. This scarring (fibrosis) causes the lungs to stiffen. The main symptom of interstitial lung disease (ILD) is shortness of breath, cough, and low oxygen levels. Other things can cause ILD, but between 3% and 5% of all cases of ILD are linked to medications.

How does this happen? And why do we keep using these medications?

Just about every medication comes with some risk of side effects. But the benefits often outweigh the risk. Many of the medications that can cause DIILD treat serious and sometimes life-threatening illnesses. Since most people do not end up with the worst side effects, it can be worth risking the side effects in order to benefit from the medication. The key is to keep a watchful eye for any side effects. The symptoms of DIILD often improve when you stop the medication in question. 

DIILD happens when a medication damages the air pockets in the lungs. Scientists do not understand exactly how this happens, but they think the medication causes inflammation. When the body tries to heal the inflammation, it heals through scarring. The scarring destroys many of the small air pockets in the lungs, making the lungs rigid. 

The end result is that people with lung fibrosis can’t let out carbon dioxide or properly oxygenate their bodies. This can cause a dry cough and shortness of breath at rest or when walking or exercising. This can start in the days, weeks, or even months after starting a new medication. 

Your provider might order a chest X-ray or a CT scan to look for signs of inflammation in the small air pockets. Experts don’t know exactly why only some people get DIILD. But there are some medications they know increase the risk. 

Treatment for drug-induced lung fibrosis

The main treatment for DIILD is stopping the medication that’s causing the problem. If it’s not safe to stop the medication entirely, you may be able to reduce the dose. Sometimes providers recommend steroids to decrease inflammation and improve recovery. The outcome depends on which medication caused the DIILD and the other medical problems you have. Many people make a complete recovery.

The bottom line

All medications have potential side effects. Some side effects are more serious than others, including side effects that affect your breathing. DIILD is one of these serious lung complications — but there’s treatment. Simply knowing it can happen can help you to spot the signs early on. So be sure to discuss any new breathing symptoms you develop with your healthcare provider — especially if you’ve recently started a new medication.