DRUG-INDUCED BRONCHOSPASM, COUGH AND BRON CHIOLITIS - ETIOLOGY AND PHYSIOPATHOLOGY

Iatrogenic respiratory disorders include bronchic manifestations (asth ma, bronchospasm, cough) and bronchiolar manifestations (constrictive or proliferative bronchiolitis). Many pharmacologic agents can induce a bronchospasm. The bronchospasm induced by acetylsalicylic acid and n onsteroidal anti-inflammatory agents, often severe, is mediated by the inhibition of the cyclooxygenase enzyme; it can be prevented by evict ion of the drug or desensitization. Leukotriene receptor antagonists a nd 5-lipoxygenase inhibitors may also be useful. Beta-blockers includi ng cardioselective beta-blockers, cholinergic agonists, inhaled agents , angiotensin-converting enzyme inhibitors (ACE), vindesine, histamine liberators, etc..., can also induce a bronchospasm. Most of the same agents can also induce ail isolated cough, particularly beta-blockers, inhaled agents, and ACE, which cause 75% of the reported cases of iat rogenic cough. ACE-induced cough usually disappears within 1 to 4 days after withdrawal of the treatment, confirming the diagnosis; ACE-indu ced cough may be prevented by sodium cromoglycate. The risk of obliter ans bronchiolitis with expiratory airflow impairment during rheumatoid arthritis is increased by D-penicillamine. Many drugs can be involved in the pathogenesis of bronchiolitis obliterans organizing pneumonia, which presents with various clinical and radiological aspects. The ph ysician has to keep in mind that bronchospasm, cough, or bronchiolitis of unknown origin, may have a iatrogenic cause.