ConditionLungs & breathing
Drug-Induced Lung Disease
Drug-induced lung disease is lung damage caused by a medicine. Hundreds of drugs can do it, but common culprits include amiodarone, methotrexate, nitrofurantoin, some chemotherapy and immunotherapy drugs, and certain biologics. It usually causes a dry cough, breathlessness and sometimes fever, appearing days to years after starting the drug. Recognizing it early matters, because stopping the medicine, often with steroids, leads to improvement in most people.
Also called: Drug-induced lung injury, drug-induced pneumonitis, medication-related lung disease, drug-induced pulmonary toxicity, drug-induced interstitial lung disease
At a glance
- What it is
- Inflammation or scarring of the lungs, or other lung injury, caused by a medicine.
- Common drugs
- Amiodarone, methotrexate, nitrofurantoin, bleomycin, checkpoint inhibitors, some biologics.
- Symptoms
- Dry cough, breathlessness, fever, tiredness, sometimes rash.
- Timing
- Days to years after starting the drug.
- Diagnosis
- Exclusion of other causes, CT scan, lung function tests, sometimes bronchoscopy.
- Treatment
- Stop the drug, steroids for moderate to severe disease, oxygen if needed.
When to get help
Call 911 or go to the ER
- Severe or rapidly worsening breathlessness, chest pain, blue lips, or oxygen saturation below 92% on a home oximeter
- Throat or tongue swelling, wheezing and hives soon after a dose of medicine
See a doctor within a day or two
- New dry cough or breathlessness while taking amiodarone, methotrexate, nitrofurantoin, chemotherapy or immunotherapy. Contact your prescriber the same day, but do not stop a critical medicine without advice
- Fever with cough and breathlessness during cancer treatment
Book a routine appointment
- A slowly worsening cough or exertional breathlessness while on long-term medicine
- Questions about lung monitoring for high-risk drugs
How medicines injure the lungs
Drugs can harm the lungs in several ways:
- direct toxicity to lung cells, often dose-related (bleomycin, amiodarone)
- immune or allergic reactions, causing pneumonitis (inflammation) similar to hypersensitivity pneumonitis
- immune activation by cancer immunotherapy (checkpoint inhibitors)
- fluid leakage into the lungs (noncardiogenic pulmonary edema), which in severe cases resembles ARDS
- bronchospasm (aspirin, beta-blockers in susceptible people)
- blood vessel injury, including pulmonary hypertension (for example, some appetite suppressants and dasatinib)
Common drugs and patterns
| Drug group | Examples | Typical pattern |
|---|---|---|
| Heart medicines | Amiodarone | Pneumonitis or fibrosis, often after months, more likely with higher total dose |
| Antibiotics | Nitrofurantoin | Acute reaction with fever within days to weeks, or chronic fibrosis after long-term use |
| Antirheumatic drugs | Methotrexate | Hypersensitivity pneumonitis, usually within the first year |
| Chemotherapy | Bleomycin, busulfan, gemcitabine, taxanes, cyclophosphamide | Pneumonitis or fibrosis, sometimes delayed |
| Cancer immunotherapy | Pembrolizumab, nivolumab, ipilimumab, durvalumab | Checkpoint inhibitor pneumonitis, at any time |
| Targeted cancer drugs | EGFR inhibitors, mTOR inhibitors, some ADCs (trastuzumab deruxtecan) | Interstitial lung disease |
| Biologics | TNF inhibitors, rituximab | Pneumonitis, infections |
| Others | ACE inhibitors (cough only), NSAIDs and aspirin (bronchospasm), opioids (pulmonary edema in overdose) | Varies |
The Pneumotox website, run by lung specialists, lists the reported lung effects of more than 1,000 drugs.
Symptoms
- dry cough
- shortness of breath, first with exertion, then at rest
- fever and chills (especially with nitrofurantoin and methotrexate)
- tiredness and weight loss
- chest tightness or pain
- rash or joint pain in some allergic reactions
- wheezing with drugs that cause bronchospasm
Risk factors
- higher dose or longer duration of the drug
- older age
- existing lung disease, such as interstitial lung disease or emphysema
- combination with radiation or oxygen (bleomycin)
- kidney impairment that raises drug levels
- smoking
Diagnosis
There is no single test. Diagnosis relies on:
- a careful medication history, including supplements, over-the-counter drugs and recent stopped drugs
- a timeline linking the drug to symptoms
- high-resolution CT of the chest, showing patterns such as ground-glass change, organizing pneumonia or fibrosis
- lung function tests, often showing reduced lung volumes and gas transfer (DLCO)
- ruling out other causes: infection, heart failure, cancer spread, and the underlying disease itself
- bronchoscopy with lavage, and sometimes biopsy, when infection must be excluded
- improvement after stopping the drug, which supports the diagnosis
Treatment
- Stop or pause the drug when possible, in discussion with the prescriber. Sometimes the benefits of a critical drug, such as an effective cancer treatment, require a careful balance.
- Corticosteroids for moderate or severe inflammation. For checkpoint inhibitor pneumonitis, steroids are standard, and additional immunosuppression is used if needed.
- Oxygen and supportive care.
- Treating complications such as infection.
- Avoid re-exposure to drugs that caused serious reactions, and record the reaction as an allergy or adverse event.
Outlook
Most acute drug-induced pneumonitis improves within weeks to months after stopping the drug, often completely. Established pulmonary fibrosis may be permanent and, in some cases, progressive. Early recognition, before scarring develops, gives the best chance of full recovery.
Prevention and monitoring
- use the lowest effective dose and duration
- baseline and periodic lung function tests and chest imaging for some high-risk drugs, such as amiodarone and bleomycin
- avoid long-term nitrofurantoin where alternatives exist, especially in older adults
- report new cough or breathlessness promptly during treatment
Frequently asked questions
What medications can cause lung damage?
Common examples include amiodarone, methotrexate, nitrofurantoin, chemotherapy drugs such as bleomycin, cancer immunotherapy drugs (checkpoint inhibitors), some targeted cancer drugs and certain biologics. Hundreds of other medicines have been reported to cause lung problems less often.
What are the symptoms of drug-induced lung disease?
Typical symptoms are a dry cough, breathlessness, fever, tiredness and sometimes chest discomfort or a rash. They can start within days or after months to years of taking the drug, and are easily mistaken for infection.
Is drug-induced lung disease reversible?
Often, yes. Inflammation usually improves after the drug is stopped, especially with steroids. Scarring (fibrosis) that has already formed may not reverse, which is why early recognition is important.
How is checkpoint inhibitor pneumonitis treated?
Mild cases may only need the immunotherapy paused and close monitoring. Moderate or severe cases are treated with steroids, and immunotherapy is stopped. If symptoms do not respond, other immune-suppressing drugs are added. Many patients recover fully.
Should I stop my medicine if I develop a cough?
Do not stop a prescribed medicine on your own, as some are essential. Contact your doctor promptly to report the cough or breathlessness. They can assess whether the drug may be responsible and arrange tests or an alternative.
Sources
This guide was written from current patient and clinical guidance, including:
- Pneumotox: The Drug-Induced Respiratory Disease Website
- National Cancer Institute: Immune checkpoint inhibitor side effects
- MedlinePlus: Drug-induced pulmonary disease
- American Society of Clinical Oncology: Management of Immune-Related Adverse Events (2021)