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Smoking Cessation Interventions; Pharmacological Aids |
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| There are
several different forms of nicotine replacement therapy; chewing gum
(2mg and 4mg doses), trans-dermal patches (16 hour and 24 hour in
varying doses), nasal spray, inhalers and sublingual tablets and
lozenges. Nicotine chewing gum and trans-dermal patches are the most
frequently used and researched forms of nicotine therapy. Nicotine chewing gum contains a nicotine resin complex that is absorbed directly through the buccal mucosa, resulting in plasma concentrations which are approximately half that produced by smoking a cigarette . It is available either as a 2 mg or 4 mg preparation, and in many countries, including Australia, is sold without a prescription from a medical practitioner. Trans-dermal patches are available in several different sizes, and deliver between 7 mg and 22 mg of nicotine over a 24-hour period, resulting in plasma levels similar to the trough levels seen in heavy smokers (2). Nicotine gum, nicotine trans-dermal patch, nicotine nasal spray , nicotine inhaler and nicotine sublingual tablets/lozenges all increase quit rates at five to 12 months approximately two-fold compared with placebo and regardless of the setting (4,6). One study that directly compared four of the six products found no difference in abstinence rates or withdrawal discomfort, although compliance was lower for inhaler and nasal spray (7). Highly dependent smokers (20 or more cigarettes per day) benefit more from 4 mg than 2 mg gum (6). Wearing a patch only during waking hours (16 hours/day) is as effective as wearing it for 24 hours/day (6). Eight weeks of patch therapy was as effective as longer courses and there was no evidence that tapered therapy was better than abrupt withdrawal (6,8). |
Combinations
of different forms of NRT are more effective than one form alone where
abstinence rates at six and 12 months were higher for combination of
nicotine patches and inhaler than placebo patches and inhaler as well
as (25% vs 22.5% at six months, 19.5% vs 14% at 12 months) (9)
, while the combination of bupropion and nicotine patch is more effective
than nicotine patch alone (10). Side effects • For nicotine gum, most side effects are relatively mild and transient, including mouth soreness, hiccups, indigestion, jaw ache and unpleasant taste. In less than two per cent of users, more severe side effects are irritability, lightheadedness, headache, excessive salivation and anorexia . • For nicotine patches, minor skin irritation at the patch site is reported by up to half of patch users and insomnia by up to a quarter of users. Comparatively rear side effects include headache, dizziness, fatigue, gastrointestinal distress, sweating, limb pain and palpitations . • Nasal spray causes nose, throat or eye irritation in most users. More serious side effects in up to a quarter of users include nausea, headache, dizziness and cold hands and feet . • Nicotine inhalers cause throat irritation and coughing in up to 50 per cent of users. Less common side-effects include nausea, bad taste in the mouth, dizziness, gastrointestinal disturbances and oral burning sensation(1). Contra-indications • Although there has been concern about the safety of NRT in smokers with cardiac disease , empirical studies have shown the nicotine patch is safe in patients with stable cardiac disease (4,11). |
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