Damage to lungs may occur from systemic as well as inhalational exposure to various
illegal drugs of abuse.
Aspiration pneumonia probably represents the most common pulmonary complication in relation to consciousness impairment. Some pulmonary consequences may be specifically related to one given drug. Prolonged smoking of marijuana may result in respiratory symptoms suggestive of
obstructive lung disease. Non-cardiogenic
pulmonary edema has been attributed to
heroin, despite debated mechanisms including attempted inspiration against a closed glottis, hypoxic damage to alveolar integrity, neurogenic vasoactive response to stress, and
opiate-induced
anaphylactoid reaction.
Naloxone-related precipitated withdrawal resulting in massive sympathetic response with heart stunning has been mistakenly implicated. In crack users, acute respiratory syndromes called "crack-lung" with
fever,
hemoptysis,
dyspnea, and pulmonary infiltration on chest X-rays have been reported up-to 48h after free-base
cocaine inhalation, with features of
pulmonary edema,
interstitial pneumonia, diffuse alveolar
hemorrhage, and eosinophil infiltration. The high-temperature of volatilized
cocaine and the presence of impurities, as well as
cocaine-induced local vasoconstriction have been suggested to explain alveolar damage. Some other drug-related pulmonary insults result from the route of drug
self-administration. In intravenous drug users, granulomatous
pneumonia with multinodular patterns on thoracic imaging is due to drug contaminants like talcum. Septic
embolism from right-sided
endocarditis represents an alternative diagnosis in case of
sepsis from pulmonary origin. Following inhalation,
pneumothorax, and
pneumomediastinum have been attributed to increased intrathoracic pressure in relation to vigorous coughing or repeated Valsalva maneuvers, in an attempt to absorb the maximal possible drug amount. In conclusion, pulmonary consequences of
illicit drugs are various, resulting in both acute life-threatening conditions and long-term functional respiratory sequelae. A better understanding of their spectrum and the implicated mechanisms of injury should help to improve patient management.