Maybe you’ve taken antibiotics to treat a urinary tract infection…or you regularly take medication to combat a chronic condition such as psoriasis or atrial fibrillation. If breathing problems (such as a hacking cough or shortness of breath) occur during that time, would you ever think that the culprit may be a drug you take for something entirely unrelated to your lungs or respiratory tract?

What most people don’t realize:  Everyday medications—including those prescribed for pain, common infections, heart conditions and cancer—can endanger your respiratory system. 

Here’s how to protect yourself…

A Bigger Problem Than Thought

Certain medications have been known to cause lung problems, including allergic reactions, abnormal buildup of fluid in the lungs and inflammation of the lung air sacs, but a recent systematic review of 156 research papers found that such complications are more common than previously understood. 

New finding: While more than 350 medications have been associated with some type of drug-induced lung problems, a study published in October 2018 in Journal of Clinical Medicine implicated 27 drugs that are most often linked to interstitial lung disease (ILD). 

What exactly is ILD? It’s a fancy term for a group of disorders that cause scarring of the lungs. The culprit might be an irritant (such as asbestos or silica dust)…an autoimmune disease (such as rheumatoid arthritis or scleroderma)…or a medication. While we may think that our lungs are safe when we take medication for, say, arthritis pain or an irregular heartbeat, there’s a catch—every organ in the body, including the lungs, has the ability to metabolize drugs.

This means that the lungs can be vulnerable to any toxic effects—even if the drug isn’t inhaled. The result can be ILD or another illness such as pneumonia, pneumonitis (inflammation of lung tissue) or pulmonary fibrosis (lung scarring). Shockingly, up to 5% of ILD cases are drug-induced, according to this research, and death rates of 50% or higher for a handful of medications, including the colorectal cancer drug panitumumab (Vectibix), were reported in some of the multiple studies reviewed. 

A Tricky Timeline

While you might assume that a drug-induced lung problem would show up right after starting to take a medication, that’s not always the case. Symptoms of ILD, which can include labored breathing and even general malaise, might develop shortly after starting a new medication (as might occur with an antibiotic, for example)…within days or weeks…or months or even years later—in some cases, even after the drug has been discontinued. This tricky timeline can make it far more difficult for you or your doctor to connect the dots. 

Getting a correct diagnosis of drug-induced ILD generally involves a thorough clinical exam, listing all medications taken over the last several years…as well as X-rays or other imaging tests, which might show changes in the lungs. Pulmonary function tests might also be ordered. In addition to blood tests to measure oxygen and carbon dioxide levels, other tests may include…

• Spirometry, in which you breathe multiple times into a tube that is connected to a computer, to measure your rate of air flow.

• Pulse oximetry, in which a probe is placed on your fingertip or a skin surface such as your ear, to estimate oxygen levels in your blood.

Once ILD has taken hold, there’s no way to rid the lungs of the telltale lesions that accompany this disease, but you can potentially stop it from progressing. A corticosteroid can reduce inflammation and ease symptoms, but this medication comes with its own potential side effects (such as weight gain, high blood pressure and bone damage) that need to be weighed against potential benefits. Lung transplants are a last-resort option for those who are most severely affected.

Top Threats

If a drug leads to ILD and an alternative medication exists, your doctor may recommend switching. Which medications are the worst offenders? Watch out for these in particular…  

• Chemotherapy drugs, including bleomycin (Blenoxane)…busulfan (Myleran)…cyclophosphamide (Cytoxan)…and panitumumab (Vectibix), among others. Biologics used as cancer immunotherapies also appear on the list, including bevacizumab (Avastin) and trastuzumab (Herceptin).

• Antiarrhythmic medications, especially amiodarone (Cordarone), which treats atrial fibrillation and is the most common cardiovascular drug linked to lung problems. As many as 6% of people taking this drug develop ILD, and an estimated 10% to 20% of them die from its lung-related complications. 

• Antibiotics, such as nitrofurantoin(Macrobid), which treats urinary tract infections…or sulfamethoxazole/trimethoprim (Bactrim), which fights ear infections, bronchitis and other bacterial infections.

• Vasodilator drugs, especially hydralazine (Apresoline), used for high blood pressure and heart failure. 

• Disease-modifying antirheumatic drugs (DMARDs), especially methotrexate(Rheumatrex, Trexall, Rasuvo), which treat autoimmune conditions, such as rheumatoid arthritis and psoriasis, as well as cancer.

• Seizure medications, such as phenytoin (Dilantin) or carbamazepine (Tegretol).

• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, ibuprofen (Motrin) and naproxen (Aleve), used for pain. Note: An NSAID user’s vulnerability to ILD is highly individualized.

• Beta-blockers, such as atenolol (Tenormin) and propranolol (Inderal), for high blood pressure.

• Statins,such as simvastatin (Zocor) and atorvastatin (Lipitor), to lower cholesterol.

Take These Precautions

It’s unfortunate that drugs we need might wreak such havoc on our lungs. But there are smart precautions to take…

• Know your baseline. Be aware of your body’s normal “feel” and function, and monitor all symptoms after you begin taking any new drug. Be alert for new or persistent trouble breathing, and consider getting a baseline spirometry test (described earlier) when starting a drug that may lead to ILD.

• Get vaccinated. Both the pneumococcal vaccine, which helps prevent pneumonia, and the flu vaccine, which is ideally received each year in early fall, before flu season begins, are important protections against ILD. Why? If you take a pill predisposing you to ILD and are then exposed to bacteria or viruses, it can spell double trouble for vulnerable lungs. By preventing pneumonia or the flu, the vaccines can mitigate any ripple effects from compromised lungs that may contribute to ILD. 

Note: The CDC recommends the annual flu vaccine for all adults…and the pneumococcal vaccine for all adults age 65 and older and anyone ages two to 64 with certain medical conditions, such as heart disease, asthma or weakened immunity. Smokers also are advised to get the pneumococcal vaccine.

• See your doctor promptly if you develop any breathing problems (such as a cough, labored breathing, shallow breathing or wheezing) that seem acute or last longer than a few days. Bring a list of medications you take, and ask the doctor if your symptoms could be due to one of these drugs.

• Get monitored. If you take one of the drugs linked to ILD, ask your doctor to monitor your lungs with one or more of the tests described earlier.