Inhaled nicotine in humans: effect on the respiratory and cardiovascular systems

Introduction:
This text is a scientific study examining the effects of inhaled nicotine on the respiratory and cardiovascular systems in humans. The study compares the effects of nicotine to those of capsaicin and two other drugs, ipratropium bromide (IPB) and sodium cromoglycate (SCG). The study design includes a series of challenges using these substances and measuring various physiological responses.

Key Points:

* The study included 24 healthy nonsmoking subjects.
* Nicotine and capsaicin were administered via a compressed air-driven nebulizer.
* The number of coughs produced by a single breath of test solution was analyzed and counted blind from the Mingograph chart.
* Total respiratory resistance (Rrs) was measured using a forced oscillation technique.
* Nicotine caused a concentration-dependent cough response, while capsaicin produced a cough response in 88% of subjects.
* Both nicotine and capsaicin increased Rrs, but the response was more rapid to capsaicin.
* Inhaled ipratropium bromide had an antitussive effect and also inhibited the nicotine-induced bronchoconstriction.
* Sodium cromoglycate did not affect cough or airway resistance changes caused by nicotine.

Main Message:
The study shows that inhaled nicotine produces a concentration-dependent cough and airway obstruction in healthy subjects, probably because of stimulation of afferent nerve endings in the bronchial mucosa and mediated through parasympathetic cholinergic pathways. The respiratory reflexes evoked by nicotine are similar to those produced by capsaicin, but it is unclear whether these reflexes are mediated by the same type of sensory nerves. The study also highlights the potential therapeutic use of ipratropium bromide in managing nicotine-induced cough and bronchoconstriction.

hansson, L., N. B. Choudry, J. a. Karlsson, and R. W. Fuller. “Inhaled Nicotine in humans: Effect on the Respiratory and Cardiovascular Systems.” Journal of applied Physiology 76, no. 6 (June 1, 1994): 2420–27. https://doi.org/10.1152/jappl.1994.76.6.2420.