More ifs and butts. . .
If you actually get to start the treatment, you must stop immediately if you suffer mouth, teeth or jaw problems, irregular or rapid heartbeat or palpitations, nausea, vomiting, dizziness or weakness.
The most popular type of nicotine replacement therapy is the nicotine gum, Nicorette. Some of the serious reactions to this occur because people don't realize they have to stop smoking while on the treatment! The extra nicotine into the system can cause fatal heart attack, or paralysis of the respiratory muscles. More common reactions include dizziness, stomach problems, insomnia and irritability.
You could, of course, just stop smoking. . .