Which potential side effect should be monitored for when using the nicotine inhaler?

The potential side effect that should be monitored for when using the nicotine inhaler is cough. The nicotine inhaler delivers nicotine vapor through the mouth, which can irritate the throat and respiratory tract, leading to a cough in some users. This side effect is particularly pertinent because, unlike the systemic side effects commonly associated with nicotine replacement therapies, the inhaler specifically targets the inhalation route, making the respiratory effects more pronounced.

By contrast, while nausea, constipation, and headache can be side effects associated with nicotine replacement therapy, they are less specific to the inhaler and can occur with various forms of nicotine delivery. Therefore, cough stands out as a noteworthy concern when monitoring patients using the nicotine inhaler, as it can also affect user adherence to the treatment plan.