What are the other Names for this Condition? (Also known as/Synonyms)

• DILD (Drug-Induced Lung Disease)
• Drug-Induced Pulmonary Disease
• Medication-Induced Pulmonary Disease

What is Drug-Induced Lung Disease? (Definition/Background Information)

• Drug-Induced Lung Disease (DILD), also known as Drug-Induced Pulmonary Disease, is a spectrum of changes that occur in the lungs secondary to intake of certain drugs. The condition affects individuals who are on medications that are known to be harmful to the lungs
• Elderly adults with pre-existing lung damage are more at risk for developing this condition
• The part of the lung affected can vary depending on the type of medication. For example these medications can affect:
  • The airways (causing asthma-like reaction)
  • The blood vessels (causing pulmonary hypertension)
  • There can be lung tissue involvement (causing pneumonia-like condition)
  • The pleura (causing pain and discomfort during breathing)
• Such reactions can occur suddenly when the medication is first used, or may even occur suddenly after the individual has used the medication without any side effects. Some medications do not cause an acute reaction, but can slowly damage various parts of the lung
• Some antibiotics, heart medications, and chemotherapeutic drugs are known to be damaging for the lungs
• The common signs and symptoms of Drug-Induced Lung Disease are cough with blood and sputum, shortness of breath, and chest pain, with complications that may include lung failure and lung fibrosis
• Diagnosis of this condition include a medical history, physical exam of lungs, and tests, such as chest x-ray and CT scan of the chest, to assess the extent of lung damage
• The first and foremost step in the treatment of Drug-Induced Lung Disease is to stop the offending agent/drug. The prognosis is variable; some individuals recover early, and some take time, and in a few cases, the lung damage may be irreversible

Who gets Drug-Induced Lung Disease? (Age and Sex Distribution)

• Drug-Induced Lung Disease affects individuals who are taking medications that are known to be harmful to the lungs. The duration of time for which the individual has been on a particular drug can influence the chances of acquiring the condition
• Elderly adults have a higher risk
• DILD affects both males and females
• This condition is observed worldwide and there is no racial or ethnic group predilection

What are the Risk Factors for Drug-Induced Lung Disease? (Predisposing Factors)

The probability of developing Drug-Induced Lung Disease cannot always be predicted. Drugs that can potentially result in a pulmonary disease may affect one individual more than the other. Some of the risk factors for the condition include:

• Elderly adults with weak immune system
• Working in an environment where one is exposed to toxins and chemicals
• Individuals with a pre-existing lung damage/injury
• Smokers

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider. 

What are the Causes of Drug-Induced Lung Disease? (Etiology)

Drug-Induced Lung Disease is caused by the use of certain medications/drugs that are injurious to the lungs. There are many different drugs that can cause the condition such as:

• Certain antibiotics that include sulfa medications and nitrofurantoin given for urinary tract infections (UTIs)
• Medication to treat heart conditions, such as amiodarone, commonly prescribed for rhythm abnormalities of the heart
• Recreational and illegal drugs such as heroin and cocaine
• Some chemotherapy drugs for cancer treatment such as bleomycin, cyclophosphamide, and methotrexate

Based on the health condition of each individual, the severity of DILD can range from mild to causing extreme harm to the lungs. In some cases, the lung damage may be irreversible.

What are the Signs and Symptoms of Drug-Induced Lung Disease?

The signs and symptoms of Drug-Induced Lung Disease depend upon the part of the lung that is involved.

• If it affects the airways, the individual may have asthma-like symptoms with breathing difficulty, cough, and occasionally blood in the sputum
• If it affects the blood vessels of the lungs, it can cause breathlessness, lower exercise tolerance, and blood in cough
• If the lung tissue is affected, it can result in signs and symptoms similar to pneumonia such as fever, fatigue, difficulty breathing, etc.
• If the pleura (the covering of the lung) are affected, pain during breathing may occur

How is Drug-Induced Lung Disease Diagnosed?

The diagnosis of Drug-Induced Lung Disease may involve:

• A complete evaluation of medical history along with a thorough physical exam
  • During the physical exam, the healthcare provider may listen to the lung  with a stethoscope, to detect the presence of any abnormal lung sounds (such as wheezing)
  • Generally, the physician is able to identify the condition based on previous medical history including the history of drug use
• To further assist in the diagnosis, other tests may be performed that include:
  • Chest X-ray
  • CT scan of the chest
  • Arterial blood gases
  • Lung function test
  • Bronchoscopy
  • Lung biopsy

Generally, stopping the medication improves the signs and symptoms in a majority of the individuals; this improvement also helps confirm the diagnosis.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis. 

What are the possible Complications of Drug-Induced Lung Disease?

The complications associated with Drug-Induced Lung Disease include:

• Hypoxemia: Abnormally low oxygen levels in blood
• Lung failure
• Lung fibrosis (scarring)
• Pulmonary hypertension that may develop over a long period of time

How is Drug-Induced Lung Disease Treated?

Treatment measures for Drug-Induced Lung Disease include:

• Discontinue the drug responsible for lung damage; the healthcare provider may prescribe alternative medications
• Depending on the severity of the condition, the patient may be placed on oxygen therapy until they overcome the reaction
• Steroids, anti-inflammatory drugs, are given to reverse the lung inflammation rapidly
• Smoking cessation
• Treatment of the underlying condition (for which the drugs were initially prescribed)

How can Drug-Induced Lung Disease be Prevented?

Preventive measures for Drug-Induced Lung Disease may include:

• Individuals who are recommended drugs that may cause lung damage should be closely observed and monitored
• In all these individuals, baseline tests to evaluate lung function should be carried out before starting on such medications
• In situations where the reaction to a medication is unpredictable, the damage to the lung cannot be avoided. But, as soon as DILD is identified, the medication should be stopped immediately
• Avoidance of smoking

What is the Prognosis of Drug-Induced Lung Disease? (Outcomes/Resolutions)

• The prognosis of Drug-Induced Lung Disease varies from one individual to another. In individuals in whom the damage is reversible, the prognosis is excellent
• Individuals in whom the damage is irreversible, the prognosis is dependent upon the extent of the lung damage
• Drug-Induced Pulmonary Disease normally disappears on discontinuation of the medication, if it presents as an acute form
• In chronic cases where the lung has been severely damaged, the condition may not be reversible; the recovery time may also be longer

Additional and Relevant Useful Information for Drug-Induced Lung Disease:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/healthy-living/healthy-lungs/