Transdermal nicotine for induction of remission in ulcerative colitis.

BACKGROUND: Ulcerative colitis is largely a disease of nonsmokers. Intermittent smokers often experience improvement in their symptoms while smoking. Nonsmokers with ulcerative colitis who begin smoking may go into remission. Randomized controlled trials were developed to test the efficacy of transdermal nicotine for the induction of remission in ulcerative colitis.

OBJECTIVES: (1) To determine the efficacy of transdermal nicotine for induction of remission in ulcerative colitis. (2) To assess adverse events associated with transdermal nicotine therapy for ulcerative colitis

SEARCH STRATEGY: The MEDLINE (via PubMed) and EMBASE databases were searched using the search criteria "ulcerative colitis" and "transdermal nicotine" or "nicotine" to identify relevant papers published between 1970 and December 2003. Manual searches of reference lists from potentially relevant papers were performed to identify additional studies. Abstracts from major gastroenterological meetings were searched to identify research submitted in abstract form only. The Cochrane Central Register of Controlled Trials and the Cochrane Inflammatory Bowel Disease Group Specialized Trials Register were also searched.

SELECTION CRITERIA: We included only randomized controlled trials in which patients with active mild to moderate ulcerative colitis were randomly allocated to receive transdermal nicotine (15 to 25 mg/day) or a placebo or another treatment (corticosteroids or mesalamine).

DATA COLLECTION AND ANALYSIS: Data extraction and assessment of the methodological quality of each trial were independently performed by each author. Any disagreement among reviewers was resolved by consensus. The primary outcome measure was the number of patients achieving clinical or sigmoidoscopic remission as defined by the primary studies (e.g. no symptoms of ulcerative colitis), and expressed as a percentage of the patients randomized (intention to treat analysis). Secondary outcomes included clinical response, adverse events and withdrawal because of adverse events.

MAIN RESULTS: Seven studies were identified, five of which met the inclusion criteria. A meta-analysis of two trials in which 71 patients were randomized to nicotine and 70 to placebo showed a statistically significant benefit for nicotine treatment. After four to six weeks of treatment 19 of 71 patients treated with transdermal nicotine were in clinical remission compared to 9 of 70 treated with placebo (OR=2.56, 95% CI 1.02-6.45). In the same group of patients improvement or remission was noted in 29 of the 71 patients assigned to nicotine compared to 14 of 70 patients assigned to placebo (OR=2.72, 95% CI 1.28 - 5.81). For patients with left sided colitis the odds ratio was 2.31 (95% CI 1.05-5.10). When transdermal nicotine was compared to standard medical therapy no significant benefit for nicotine was observed. After four to six weeks of standard therapy (oral prednisone or mesalamine), 34 of 63 patients were in clinical or sigmoidoscopic remission compared to 33 of 66 patients treated with transdermal nicotine (OR=0.77, 95% CI 0.37-1.60). A meta-analysis of all five studies which included 137 patients treated with transdermal nicotine and 133 patients treated with a placebo or standard therapy demonstrated no statistically significant benefit of nicotine therapy (OR=1.23; 95% CI 0.71-2.14). Patients treated with transdermal nicotine were significantly more likely to withdrawal due to adverse events than patients treated with placebo or standard medical therapy (OR=5.82, 95% CI, 1.66 - 20.47) and were significantly more likely to suffer from an adverse event than patients treated with placebo or standard medical therapy (OR=3.54, 95% CI, 2.07 - 6.08).

REVIEWERS' CONCLUSIONS: The results of this review provide evidence that transdermal nicotine is superior to placebo for the induction of remission in patient's with ulcerative colitis. The review did not identify any significant advantage for transdermal nicotine therapy compared to standard medical therapy. Adverse events associated with transdermal nicotine are significant and limit its use in some patients.