Nicotine replacement therapy for smoking cessation

 

Abstract

Background

The aim of nicotine replacement therapy (NRT) is temporarily to replace much of the nicotine from cigarettes to reduce motivation to smoke and nicotine withdrawal symptoms, thus easing the transition from cigarette smoking to complete abstinence.

Objectives

The aims of this review were:
To determine the effect of NRT compared to placebo in aiding smoking cessation, and to consider whether there is a difference in effect for the different forms of NRT (chewing gum, transdermal patches, nasal spray, inhalers and tablets/lozenges) in achieving abstinence from cigarettes.
To determine whether the effect is influenced by the dosage, form and timing of use of NRT; the intensity of additional advice and support offered to the smoker; or the clinical setting in which the smoker is recruited and treated.
To determine whether combinations of NRT are more likely to lead to successful quitting than one type alone.
To determine whether NRT is more or less likely to lead to successful quitting compared to other pharmacotherapies.

Search methods

We searched the Cochrane Tobacco Addiction Group trials register for papers with 'nicotine' or 'NRT' in the title, abstract or keywords. Date of most recent search July 2007.

Selection criteria

Randomized trials in which NRT was compared to placebo or to no treatment, or where different doses of NRT were compared. We excluded trials which did not report cessation rates, and those with follow up of less than six months.

Data collection and analysis

We extracted data in duplicate on the type of participants, the dose, duration and form of nicotine therapy, the outcome measures, method of randomization, and completeness of follow up.
The main outcome measure was abstinence from smoking after at least six months of follow up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. We calculated the risk ratio (RR) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model.

Main results

We identified 132 trials; 111 with over 40,000 participants contributed to the primary comparison between any type of NRT and a placebo or non-NRT control group. The RR of abstinence for any form of NRT relative to control was 1.58 (95% confidence interval [CI]: 1.50 to 1.66). The pooled RR for each type were 1.43 (95% CI: 1.33 to 1.53, 53 trials) for nicotine gum; 1.66 (95% CI: 1.53 to 1.81, 41 trials) for nicotine patch; 1.90 (95% CI: 1.36 to 2.67, 4 trials) for nicotine inhaler; 2.00 (95% CI: 1.63 to 2.45, 6 trials) for oral tablets/lozenges; and 2.02 (95% CI: 1.49 to 3.73, 4 trials) for nicotine nasal spray. The effects were largely independent of the duration of therapy, the intensity of additional support provided or the setting in which the NRT was offered. The effect was similar in a small group of studies that aimed to assess use of NRT obtained without a prescription. In highly dependent smokers there was a significant benefit of 4 mg gum compared with 2 mg gum, but weaker evidence of a benefit from higher doses of patch. There was evidence that combining a nicotine patch with a rapid delivery form of NRT was more effective than a single type of NRT. Only one study directly compared NRT to another pharmacotherapy. In this study quit rates with nicotine patch were lower than with the antidepressant bupropion.

Authors' conclusions

All of the commercially available forms of NRT (gum, transdermal patch, nasal spray, inhaler and sublingual tablets/lozenges) can help people who make a quit attempt to increase their chances of successfully stopping smoking. NRTs increase the rate of quitting by 50-70%, regardless of setting.
The effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the individual. Provision of more intense levels of support, although beneficial in facilitating the likelihood of quitting, is not essential to the success of NRT.

 

Plain language summary

Can nicotine replacement therapy (NRT) help people quit smoking

NRT aims to reduce withdrawal symptoms associated with stopping smoking by replacing the nicotine from cigarettes. NRT is available as skin patches that deliver nicotine slowly, and chewing gum, nasal spray, inhalers, and lozenges/tablets, all of which deliver nicotine to the brain more quickly than from skin patches, but less rapidly than from smoking cigarettes. This review includes 132 trials of NRT, with over 40,000 people in the main analysis. It found evidence that all forms of NRT made it more likely that a person's attempt to quit smoking would succeed. The chances of stopping smoking were increased by 50 to 70%. Most of the studies were performed in people smoking more than 15 cigarettes a day. What limited evidence there is suggests no overall difference in effectiveness of different forms of NRT nor a benefit for using patches beyond 8 weeks. NRT works with or without additional counselling, and does not need to be prescribed by a doctor. Heavier smokers may need higher doses of NRT. People who use NRT during a quit attempt are likely to further increase their chance of success by using a combination of the nicotine patch and a faster acting form. Preliminary data suggests that starting to use NRT shortly before the planned quit date may increase the chance of success. Adverse effects from using NRT are related to the type of product, and include skin irritation from patches and irritation to the inside of the mouth from gum and tablets. There is no evidence that NRT increases the risk of heart attacks.

 

摘要

背景

尼古丁替代治療(nicotine replacement therapy)戒菸

尼古丁替代治療的目的在暫時取代香菸中大部分的尼古丁來減少吸菸的動機及尼古丁戒斷症狀，因而緩和自吸菸到完全戒菸的轉換期

目標

這篇回顧的目的在確定:尼古丁替代療法相較於安慰劑在幫助戒菸上的效果，考慮是否不同的尼古丁替代療法(口嚼錠(chewing gum)、經皮貼片(transdermal patc)、鼻噴劑(nasal spray)、吸入劑(inhalers)、及錠劑/含錠(tablets/lozenges))之間在戒菸效果上有差異。確定是否效果會受劑量、形式及使用時間影響；提供給吸菸者額外建議及支持的強度；或者吸菸者被納入及治療的臨床處置。確定是否合併方式比單一尼古丁替代治療較能夠成功戒菸。確定相較於其他的藥物治療，是否尼古丁替代療法比較能成功戒菸。

搜尋策略

我們搜尋至2007年七月Cochrane Tobacco Addiction Group trials register 中文章表題、摘要或關鍵字有‘nicotine’或‘NRT’者。

選擇標準

隨機試驗比較尼古丁替代療法與安慰劑或與沒有治療或不同劑量的尼古丁替代療法間的差別。我們排除缺少戒除率報告或追蹤少於六個月的試驗。

資料收集與分析

我們收集資料，採取二分法來分類受試者、劑量、治療的時間、形式、結果的評估、隨機的方法、及追蹤的完整性。主要的結果評估是在追蹤下戒除吸菸至少六週。我們用最嚴謹的定義來檢視試驗中的戒菸，及能取得的生化性認證率;我們計算每個試驗的相對危險率。如果條件合適，我們使用MantelHaenszel固定效果(fixed effect)模式進行統合分析。

主要結論

我們辨識出132個試驗；其中111個涵蓋超過40,000名受試者來比較任何形式的尼古丁替代療法及安慰劑或非尼古丁替代療法的控制組。任何形式的尼古丁替代療法與控制組的戒菸相對危險比為1.58(95% 信賴區間confidence interval [CI]: 1.50 to 1.66)。個別的相對危險比在尼古丁口嚼錠為1.43 (95% CI: 1.33 to 1.53, 53 trials)；在尼古丁貼片為 1.66 (95% CI: 1.53 to 1.81, 41 trials)；在尼古丁吸入劑(nicotine inhaler)為1.90 (95% CI: 1.36 to 2.67, 4 trials)；在尼古丁錠劑為 2.00 (95% CI: 1.63 to 2.45, 6 trials)；而在尼古丁鼻噴劑為2.02 (95% CI: 1.49 to 3.73, 4 trials)。治療效果大部分獨立於治療長度、額外提供的支持強度、或提供的尼古丁治療的環境。效果類似於小型族群在針對非處方給予的尼古丁替代療法使用上的研究。在高度依賴的菸癮者身上，4毫克口嚼錠相較於2毫克的口嚼錠有顯著的效益，但在高劑量的貼片只有微弱證據顯示療效。有證據顯示結合尼古丁貼片與一種快速釋放形式的尼古丁替代療法比單一的尼古丁替代療法更有療效。只有一個研究直接比較尼古丁替代療法與另外的藥物治療。在這一研究，尼古丁貼片的戒菸率低於抗憂鬱劑bupropion。

作者結論

所以商業上可取得的尼古丁替代療法(口嚼錠、經皮貼片、鼻噴液、吸入劑及舌下錠/含錠)可以幫助試圖戒菸的人們，增加戒菸成功率。尼古丁替代療法在任何戒菸環境下增加戒菸率約50 – 70%。尼古丁替代療法的療效大部分獨立於額外對個案的支持強度。提供更強的支持，雖然有利於強化戒菸的可能性，但非對尼古丁替代療法的成功並非是必要的。

翻譯人

本摘要由彰化基督教醫院李柏賢翻譯

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌

總結

所有形式的尼古丁替代療法可以幫助人門戒菸。使用尼古丁替代療法的目的在藉由替代香菸中的尼古丁來減少停止吸菸時的戒斷症狀。尼古丁替代療法可由皮膚貼片緩慢釋放尼古丁，或由口嚼錠、鼻噴劑、吸入劑及錠劑/含錠以快於貼片的方式將尼古丁送至大腦，但仍慢於吸菸的方式。這篇回顧包含132個尼古丁替代療法的試驗，分析超過40,000名個案。證據顯示所有的尼古丁替代療法能讓嘗試戒菸的人容易戒菸成功。成功戒菸的機會增加50 – 70%。大部分研究的個案是每天吸菸超過15支。證據上的限制在於任何形式的尼古丁替代療法或使用貼片超過8週並沒有治療上的差異。不論是否有額外的諮商，尼古丁替代療法都有效，且其有效不必然需要醫師開立處方。重度菸癮者可能需要較高劑量的尼古丁替代療法。企圖戒菸的人們合併使用尼古丁貼片及另一較快速作用的形式可能增加戒菸的成功率。初步的資料建議在計畫戒菸日前短暫使用尼古丁替代療法可以增加成功率。尼古丁替代療法的副作用與產品的型式有關，包含貼片造成的皮膚刺激，口嚼錠及錠劑造成的口腔內側的刺激。沒有證據表示尼古丁替代療法會增加心臟病發作的危險。