Drug-induced pulmonary disease

Definition

Drug-induced pulmonary disease is a lung disease caused by an adverse (bad) reaction to a medication.

Causes, incidence, and risk factors

Many types of lung injury can result from medications, and it is often impossible to predict who will develop lung disease resulting from a medication or drug.

The types of lung diseases that may result from medications include:

• Allergic reactions -- asthma, hypersensitivity pneumonitis, or eosinophilic pneumonia
• Coughing or bronchitis
• Inflammation of the lung air sacks (pneumonitis or infiltration)
• Interstitial fibrosis (scarring)
• Pulmonary edema (swelling in the lungs caused by fluid buildup in the tissues)
• Alveolar hemorrhage (bleeding into the lung air sacks)
• Pleural effusion (fluid in the tissues surrounding the lungs)
• Lung vasculitis (inflammation of lung blood vessels)
• Mediastinal inflammation (inflammation of the spaces surrounding the lungs and heart)
• Swollen lymph nodes (lymphadenopathy)
• Respiratory failure
• Granulomatous lung disease -- a type of tumor in the lungs
• Drug-induced lupus erythematosus

Numerous drugs are known to cause lung disease in some people including chemotherapy agents, certain antibiotics, illicit drugs, certain cardiovascular drugs, and many others.

Symptoms

• Cough
• Wheezing
• Shortness of breath
• Chest pain
• Bloody sputum
• Fever

Note: Symptoms may be varied.

Signs and tests

• Abnormal breath sounds revealed by a physical examination with a stethoscope
• Chest x-ray
• Chest CT scan
• CBC with differential
• Bronchoscopy
• Thoracentesis if pleural effusion is present
• Rarely, difficult to diagnose cases may require lung biopsy

Treatment

Treatment consists mainly of discontinuing the offending drug immediately, and beginning supportive management of the symptoms. For instance, you may need inhaler therapy and oxygen until the drug-induced lung disease improves. Challenge tests (reintroducing the suspected medication to see if symptoms recur) are rarely performed. Steroid therapy such as prednisone, to quickly reverse the lung inflammation caused by the offending drug, is sometimes used.

Expectations (prognosis)

Acute episodes usually resolve within 48 - 72 hours after the medication has been discontinued, but chronic syndromes may take longer to resolve. Some drug-induced lung diseases such as pulmonary fibrosis may never resolve.

Complications

• Respiratory failure
• Diffuse interstitial pulmonary fibrosis
• Hypoxemia (low blood oxygen)

Calling your health care provider

Call your health care provider if symptoms of this disorder occur.

Prevention

Previous reaction to medication should be noted, so that you can avoid the medication. Wear a medical allergy bracelet if you have known drug reactions. Avoid the abuse of illicit drugs, as this will prevent many drug-induced lung diseases.

References

Murray J, Nadel J. Textbook of Respiratory Medicine. 3rd ed. Philadelphia, Pa: WB Saunders; 2000. 

Noble J. Textbook of Primary Care Medicine. 3rd ed. St. Louis, Mo: Mosby; 2001.

Illustrations

Respiratory system