Drug-induced pulmonary disease is not a single disorder. Many drugs can cause lung problems in people who have no other lung disorders. The type of problem depends on the drug involved, but many of the drugs are thought to cause an allergic-type reaction Overview of Allergic Reactions Allergic reactions (hypersensitivity reactions) are inappropriate responses of the immune system to a normally harmless substance. Usually, allergies cause sneezing, watery and itchy eyes, a... read more 
. The disease is often more severe in older people. When not caused by an allergic-type reaction, the extent and severity of the disease are sometimes related to how large the drug dose was and how long the drug was taken.
Depending on the drug, people develop cough, wheezing, shortness of breath, or other lung symptoms. Symptoms may develop
Slowly over weeks to months
Suddenly and become severe
Diagnosis and treatment are the same, stopping the drug and observing whether the person's symptoms lessen.
Doctors may do pulmonary function testing Pulmonary Function Testing (PFT) Pulmonary function tests measure the lungs' capacity to hold air, to move air in and out, and to absorb oxygen. Pulmonary function tests are better at detecting the general type and severity... read more 
before people begin taking drugs that are known to cause lung problems, but the benefits of screening for prediction or early detection of drug-induced pulmonary disease are unknown.
(See also Overview of Interstitial Lung Diseases Overview of Interstitial Lung Diseases Interstitial lung disease (also called diffuse parenchymal disease) is a term used to describe a number of different disorders that affect the interstitial space. The interstitial space consists... read more .)
