P1.2.1 Nicotine replacement therapy

All forms of nicotine replacement therapy (NRT) appear to be useful in aiding smoking cessation.(Stead et al., 2008) NRT is most suitable for highly dependent smokers who are motivated to quit. There is little evidence for its role in those who smoke up to 15 cigarettes daily. The choice of type of NRT depends on patient preference, needs and tolerance. NRT is more effective when combined with counselling and behav­ioural therapy.(Schwartz, 1987)

NRT is safe in patients with stable cardiac disease such as angina pectoris [evidence level I].(Joseph et al., 1996, Mahmarian et al., 1997, Nitenberg and Antony, 1999) [evidence level II], and acute coronary syndromes (Meine et al., 2005) [evidence level III-2]. NRT produces lower peak levels of nicotine than active smoking, so theoretically, should be safer than smoking, even in patients with unstable disease.

Nicotine transdermal patch: A steady nicotine level (about half that of smoking) is maintained to reduce with­drawal symptoms. However, the patch does not provide the peak nicotine levels of smoking which reinforce the addic­tion. Patch use increases the sustained quit rate at 12 months compared with placebo (OR=1.51, 95% CI 1.35 to 1.70, 10,928 participants, NNT=25, 95% CI 19 to 36). The strength of patch recommended depends on the degree of nicotine dependence, indicated by number and strength of cigarettes smoked daily. A range of strengths are available in both 24 hour and 16 hour patches durations, although there is no evidence of increased efficacy for longer duration of action. Using higher doses produces higher blood nicotine levels and provides more relief of morning cravings, but only produces a small increase in efficacy (OR=1.15, 95% CI 1.01 to 1.30, 4,634 participants) Six to eight weeks of use are generally recommended, with no evidence of increased efficacy for longer durations, and tapering of the nicotine dose over this time, often occurs, although there is no evidence of increased efficacy (OR=0.99, 95% CI 0.74 to 1.32, 264 participants). The only significant adverse side effect is skin irritation, which is generally mild and rarely leads to cessation of use.

Nicotine gum: Nicotine is rapidly absorbed through the oral mucous membrane, so gum should be chewed only two to three times per minute to avoid excessive salivation, swallowing of nicotine and gastrointestinal adverse effects. The blood levels achieved by nicotine chewing gum are one-third (2 mg gum) or two-thirds (4 mg gum) those of smoking. Nicotine gum also increases the sustained 12 month quit rate compared to placebo (OR=1.43 95% CI 1.31 to 1.56). The 4mg dose gum is more effective than the 2mg in high dependency smokers (OR=1.85 95% CI 1.36 to 2.50, 618 participants), but there is no significant difference between them in efficacy for low dependency smokers. Patients should taper the dose gradually, but dependence on the gum can occur in up to 20% of users. Most patients should have stopped using the gum within three months.

Nicotine lozenge: Nicotine lozenges are available in 2 mg and 4 mg doses and increase quit rates over placebo measured at 6 months or beyond (OR=2.00 95% CI 1.63 to 2.45, 3,109 participants). No special technique is required — the lozenge is held in the mouth and moved around periodically until it dissolves. As the lozenge dissolves, it releases about 25% more nicotine than the equivalent dose of gum. Patients should reduce the number of lozenges they are using over 12 weeks, remaining on the same strength lozenge throughout. Lozenges may be preferable for denture wearers who wish to use oral NRT.

Nicotine inhaler: The nicotine inhaler consists of a plastic mouthpiece and cartridge containing 10 mg of nicotine. The inhaler produces nicotine concentrations that are a third those achieved with smoking. The inhaler is useful for smokers who miss the hand-to-mouth action of smoking, or who have problems with the gum. The inhaler increases the quit rate over placebo measured at 6 months or beyond (OR=1.90 95% CI 1.36 to 2.67, 976 participants). The recommended maximum period of use is 16 weeks.