TABLE 2.4.

Drugs Causing Cough

Drug	Mechanism
Tobacco, marijuana	Direct irritants
β-Adrenergic blockers	Potentiate asthma
ACE inhibitors	(?) Possibly potentiate asthma
Bethanechol	Potentiates asthma
Nitrofurantoin	(?) Via oxygen radicals vs via autoimmunity
Antineoplastic agents	Various (including pneumonitis/fibrosis, hypersensitivity, noncardiogenic pulmonary edema)
Sulfasalazine	(?) Causes bronchiolitis obliterans
Penicillamine	(?) Causes bronchiolitis obliterans
Diphenylhydantoin	Hypersensitivity pneumonitis
Gold	(?) Causes interstitial fibrosis
Aspirin, NSAIDs	Potentiate asthma
Nebulized antibiotics	(?) Direct irritant
Inhaled/nebulized bronchodilators	Increases tracheal/bronchial wall instability in airway malacia; or via reaction to vehicle
Theophylline, caffeine	Indirect, via worsened gastroesophageal reflux (relaxation of lower esophageal sphincter)
Metabisulfite	Induces allergic asthma
Cholinesterase inhibitors	Induce mucus production (bronchorrhea)

ACE, angiotensin-converting enzyme; NSAIDs, nonsteroidal anti-inflammatory drugs.