ABSTRACT

Coughing is the most common manifestation of respiratory tract symptoms. It both defends against respiratory pathogens and helps to clear the tracheobronchial tree for an optimal gas exchange. The physical and chemical composition of the inhaled substance may precipitate coughing by direct stimulation of cough receptors. The most likely mechanism whereby TRPV1 stimulation gives rise to drug side-effects is through its acid sensitivity. The TRPA1 receptor plays an important modulating role in cough reflex sensitivity and may be particularly important in smokers through its potent agonist acreolin. There is one circumstance where the precipitant of drug-induced cough may not be located within the airways. Cough presumed to be drug-induced because the symptom disappeared on drug discontinuation has been described during treatments with morphine, omeprazole, sertraline, sirolimus, interferon, mycophenolate mofetil and topiramate. To manage cough induced by drugs, the proposed option should be to stop the drug and replace it with one of a different class.