Other conditions
Nicotine replacement therapies should be used cautiously in individuals with the following conditions: severe reactive airway diseases (for nasal spray), chronic nasal disorders such as sinusitis, polyps, rhinitis, or allergy (for nasal spray), diabetes (insulin-dependent), gastrointestinal diseases such as esophagitis, active gastric or peptic ulcer disease, liver problems, hyperthyroidism,pheochromocytoma, phenylketonuria (for lozenges), renal problems, and skin conditions such as psoriasis or dermatitis (for the transdermal patch). Mechanism of action
Nicotine replacement therapy works by reducing cravings due to nicotine addiction. Smoking cigarettes releases high doses of nicotine to the brain in a matter of seconds as opposed to low doses released over a period of minutes to hours by the various forms of nicotine replacement therapy. Nicotine from NRT does not reach as high a concentration in the blood as does nicotine from smoke inhalation due to different absorption methods. NRT relies on systemic venous absorption, whereas nicotine from cigarettes reaches the arterial system. Nicotine replacement products vary in the time it takes for the nicotine to enter the body and the total time nicotine stays in the body. The more quickly a dose of nicotine is delivered and absorbed, the higher the addiction risk. It is possible to become dependent on some NRTs.Nicotine patches are applied to the skin and continuously administer a stable dose of nicotine slowly over 16–24 hours. Nicotine gum, nicotine sprays, nicotine toothpicks, nicotine sublingual tablets, and nicotine lozenges administer nicotine orally with quicker nicotine uptake into the body but lasting a shorter amount of time.
Eosinophilic bronchitis (EB) is a type of airway inflammation due to excessive mast cell recruitment and activation in the superficial airways as opposed to the smooth muscles of the airways as seen in asthma. It often results in a chronic cough. Lung function tests are usually normal. Inhaled corticosteroids are often an effective treatment. Signs and symptoms
The most common symptom of eosinophilic bronchitis is a chronic dry cough lasting more than 6–8 weeks. Eosinophilic bronchitis is also defined by the increased number of eosinophils, a type of white blood cell, in the sputum compared to that of healthy people. As patients with asthma usually present with eosinophils in the sputum as well, some literature distinguish the two by classifying the condition as non-asthmatic eosinophilic bronchitis (NAEB) versus eosinophilic bronchitis in asthma. Non-asthmatic eosinophilic bronchitis is different from asthma in that it does not have airflow obstruction or airway hyperresponsiveness. Along with eosinophils, the number of mast cells, another type of white blood cell, is also significantly increased in the bronchial wash fluid of eosinophilic bronchitis patients compared to asthmatic patients and other healthy people. Asthmatic patients, however, have greater number of mast cells that go into the smooth muscle of the airway, distinguishing it from non-asthmatic eosinophilic bronchitis. The increased number of mast cells in the smooth muscle correlate with the increased hyperresponsiveness of the airway seen in asthma patients, and the difference in the mast cell infiltration of the smooth muscle may explain why eosinophilic bronchitis patients do not have airway hyperresponsiveness.