Does smoking improve colitis?

Smoking cessation intervention for reducing disease activity in chronic autoimmune inflammatory joint diseases

BACKGROUND

Chronic inflammatory joint diseases (IJDs) affect 1% to 2% of the population in developed countries. IJDs include rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PsA), and other forms of spondyloarthritis (SpA). Tobacco smoking is considered a significant environmental risk factor for developing IJDs. There are indications that smoking exacerbates the symptoms and worsens disease outcomes.

OBJECTIVES

The objective of this review was to investigate the evidence for effects of smoking cessation interventions on smoking cessation and disease activity in smokers with IJD.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Library; PubMed/MEDLINE; Embase; PsycINFO; the Cumulative Index to Nursing and Allied Health Literature (CINAHL); and three trials registers to October 2018.

SELECTION CRITERIA

We included randomised controlled trials testing any form of smoking cessation intervention for adult daily smokers with a diagnosis of IJD, and measuring smoking cessation at least six months after baseline.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane.

MAIN RESULTS

We included two studies with 57 smokers with a diagnosis of rheumatoid arthritis (RA). We identified no studies including other IJDs. One pilot study compared a smoking cessation intervention specifically for people with RA with a less intensive, generic smoking cessation intervention. People included in the study had a mean age of 56.5 years and a disease duration of 7.7 years (mean). The second study tested effects of an eight-week cognitive-behavioural patient education intervention on cardiovascular disease (CVD) risk for people with RA and compared this with information on CVD risk only. The intervention encouraged participants to address multiple behaviours impacting CVD risk, including smoking cessation, but did not target smoking cessation alone. People included in the study had a mean age of 62.2 years (intervention group) and 60.8 years (control group), and disease duration of 11.6 years (intervention group) and 14.1 years (control group). It was not appropriate to perform a meta-analysis of abstinence data from the two studies due to clinical heterogeneity between interventions. Neither of the studies individually provided evidence to show benefit of the interventions tested. Only one study reported on adverse effects. These effects were non-serious, and numbers were comparable between trial arms. Neither of the studies assessed or reported disease activity or any of the predefined secondary outcomes. We assessed the overall certainty of evidence as very low due to indirectness, imprecision, and high risk of detection bias based on GRADE.

AUTHORS' CONCLUSIONS

We found very little research investigating the efficacy of smoking cessation intervention specifically in people with IJD. Included studies are limited by imprecision, risk of bias, and indirectness. Neither of the included studies investigated whether smoking cessation intervention reduced disease activity among people with IJD. High-quality, adequately powered studies are warranted. In particular, researchers should ensure that they measure disease markers and quality of life, in addition to long-term smoking cessation.

Systematic review with meta-analysis: the effect of tobacco smoking on the natural history of ulcerative colitis

BACKGROUND

Tobacco smoking is associated with a reduced risk of developing ulcerative colitis (UC). A high proportion of UC patients perceive a benefit in disease outcomes secondary to smoking. However, the effects of smoking on the natural history of UC are uncertain.

AIM

To conduct a systematic review and meta-analysis of the effects of tobacco smoking on the natural history of UC.

METHODS

A search of MEDLINE, EMBASE and EMBASE classic was carried out (up to December 2015) to identify observational studies reporting data on smoking and rates of colectomy, flare of disease activity, proximal disease extension, and development of pouchitis following panproctocolectomy and ileal pouch-anal anastomosis in patients with UC. Dichotomous data were pooled to obtain odds ratios (ORs), with 95% confidence intervals (CIs).

RESULTS

The search identified 16 eligible studies: five (2615 patients) studying colectomy; four (620 patients) reporting on flare of disease activity; four (687 patients) examining proximal disease extension and three (355 patients) assessing development of pouchitis. Compared with nonsmokers, the odds of colectomy (OR = 0.89; 95% CI 0.62-1.26), flare of disease activity (OR = 1.26; 95% CI 0.65-2.44), proximal extension of disease (OR = 0.57; 95% CI 0.20-1.66) or the development of pouchitis (OR = 0.57; 95% CI 0.21-1.53) were not significantly lower in smokers.

CONCLUSIONS

Smoking may not improve the natural history of ulcerative colitis. Given the health benefits of smoking cessation and the lack of clear benefit in ulcerative colitis, smoking cessation advice should be incorporated into guidance on the management of ulcerative colitis.

High Rates of Smoking Especially in Female Crohn's Disease Patients and Low Use of Supportive Measures to Achieve Smoking Cessation--Data from the Swiss IBD Cohort Study

BACKGROUND AND AIMS

Smoking is a crucial environmental factor in inflammatory bowel disease [IBD]. However, knowledge on patient characteristics associated with smoking, time trends of smoking rates, gender differences and supportive measures to cease smoking provided by physicians is scarce. We aimed to address these questions in Swiss IBD patients.

METHODS

Prospectively obtained data from patients participating in the Swiss IBD Cohort Study was analysed and compared with the general Swiss population [GSP] matched by age, sex and year.

RESULTS

Among a total of 1770 IBD patients analysed [49.1% male], 29% are current smokers. More than twice as many patients with Crohn's disease [CD] are active smokers compared with ulcerative colitis [UC] [UC, 39.6% vs CD 15.3%, p < 0.001]. In striking contrast to the GSP, significantly more women than men with CD smoke [42.8% vs 35.8%, p = 0.025], with also an overall significantly increased smoking rate compared with the GSP in women but not men. The vast majority of smoking IBD patients [90.5%] claim to never have received any support to achieve smoking cessation, significantly more in UC compared with CD. We identify a significantly negative association of smoking and primary sclerosing cholangitis, indicative of a protective effect. Psychological distress in CD is significantly higher in smokers compared with non-smokers, but does not differ in UC.

CONCLUSIONS

Despite well-established detrimental effects, smoking rates in CD are alarmingly high with persistent and stagnating elevations compared with the GSP, especially in female patients. Importantly, there appears to be an unacceptable underuse of supportive measures to achieve smoking cessation.

Environmental factors and their impact on the intestinal microbiota: a role for human disease?

The intestinal microbiota and its potential role in human health and disease have come into the focus of interest in recent years. An important prerequisite for the achieved advances with regard to a better characterization of its complex composition and influencing factors is the increasing availability and affordability of culture-independent methods, such as high-throughput sequencing technologies. We discuss some general aspects of the intestinal microbiota. Recent insights into its potential pathogenetic role in the metabolic syndrome and inflammatory bowel disease will also be discussed that imply an impact of smoking status and smoking cessation on intestinal microbial composition.

Novel insights on the effect of nicotine in a murine colitis model

Studies showed that nicotine has a positive influence on symptoms of ulcerative colitis. In the present study, we explored the effect of nicotine treatment using different routes of administration in the dextran sodium sulfate (DSS) colitis mouse model. We also investigated the effects of cotinine, a major metabolite of nicotine, in the model. C57BL6 adult male mice were given DSS solution freely in the drinking water for seven consecutive days, and tap water was given thereafter. Disease severity, length of the colon, colon tissue histology, and inflammatory markers, including colonic myeloperoxidase activity and colonic tumor necrosis factor-α levels, were evaluated. The effect of nicotine and cotinine treatments via various different routes of administration were examined the DSS model. In addition, we measured the plasma levels of nicotine and cotinine in our treatment protocols. Administration of low, but not high, doses of oral nicotine in DSS-treated mice resulted in a significant decrease in disease severity, histologic damage scores, as well as colonic level of tumor necrosis factor-α. However, the anti-inflammatory effect of nicotine was not seen after chronic s.c. or minipump infusion of the drug. Differences in plasma levels of nicotine and cotinine do not seem to account for this lack of effect. Finally, oral cotinine alone failed to show a significant effect in the DSS model of colitis. These results highlight that dose and route of administration play a critical role in the protective effect of nicotine in the DSS mouse colitis model.

Impact of environmental and dietary factors on the course of inflammatory bowel disease

Besides their possible effects on the development of inflammatory bowel disease (IBD), some environmental factors can modulate the clinical course of both ulcerative colitis (UC) and Crohn’s disease (CD). This review is mainly devoted to describing the current knowledge of the impact of some of these factors on the outcome of IBD, with special emphasis on smoking and diet. Although the impact of smoking on the susceptibility to develop CD and UC is firmly established, its influence on the clinical course of both diseases is still debatable. In CD, active smoking is a risk factor for postoperative recurrence. Beyond this clinical setting, smoking cessation seems to be advantageous in those CD patients who were smokers at disease diagnosis, while smoking resumption may be of benefit in ex-smokers with resistant UC. The role of dietary habits on the development of IBD is far from being well established. Also, food intolerances are very frequent, but usually inconsistent among IBD patients, and therefore no general dietary recommendations can be made in these patients. In general, IBD patients should eat a diet as varied as possible. Regarding the possible therapeutic role of some dietary components in IBD, lessons should be drawn from the investigation of the primary therapeutic effect of enteral nutrition in CD. Low-fat diets seem to be particularly useful. Also, some lipid sources, such as olive oil, medium-chain triglycerides, and perhaps omega-3 fatty acids, might have a therapeutic effect. Fermentable fiber may have a role in preventing relapses in inactive UC.

Low-dose smoking resumption in ex-smokers with refractory ulcerative colitis

BACKGROUND AND AIM

Ulcerative colitis (UC) is primarily a disease of non-smokers. Ex-smokers may have a more refractory disease course and anecdotal evidence in non-controlled clinical trials have suggested that smoking resumption, or the administration of nicotine, may ameliorate signs and symptoms of UC in ex-smokers. We report outcomes of ex-smokers with refractory UC who resumed low-dose cigarette smoking.

METHODS

17 ex-smokers with refractory UC were identified. Clinical remission was defined as a disease activity index score of 0.

RESULTS

Two out of 17 patients refused the recommendation to resume smoking. Of the 15 patients who resumed smoking, the mean daily number of cigarettes was 8.6. Fourteen out of those 15 patients who resumed smoking were able to maintain prolonged clinical remission off steroids. One out of the 15 patients failed to improve and required oral steroids. Another patient was compelled to quit smoking since he became addicted. His disease flared after maintaining a prolonged remission of 3 years and he eventually underwent surgery. Three out of these 15 patients switched from cigarettes smoking to nicotine compounds and continued to maintain remission.

CONCLUSION

Resumption of low dose smoking in a selected group of ex-smokers with refractory UC may ameliorate signs and symptoms. Quality of life, medication side effects, and smoking risk factors should all be considered and discussed with patients. Smokers should be meticulously followed for compliance with "low-dose" regimen and all associated smoking risks.

Clinical predictors of aggressive/disabling disease: ulcerative colitis and crohn disease

Many clinical factors predict the aggressive course of CD. Younger age at initial diagnosis, the presence of perianal lesions, ileal involvement, smoking, and the need for therapy with corticosteroids are the major predictors of disabling disease or change of behavior to a more aggressive disease. On the other hand, treatment with azathioprine and biologic agents and colonic localization of disease are the major factors that are predictive of less aggressive CD course. The problem we face with determining the factors that increase the risk of disabling disease is that there is no standardized and consistent definition of disabling or aggressive disease. Only two studies analyzed predictors using the same definition of aggressive disease. Only Beaugerie and colleagues developed the score predictive of disabling disease based on three independent factors associated with disabling course that were present at the time of initial diagnosis of CD (requirement of corticosteroids, age less than 40 years, and presence of perianal disease). This score ranged from 0 to 3 points based on the presence of given parameters. The positive predictive value was 0.91 and 0.93 in patients having two or three risk factors, 0.61 for no factors present, and 0.67 for one factor present. In order to determine factors predictive of disabling CD there is a need to establish consistent definition of disabling disease with subsequent future studies on large group of patients to validate such definition and determine factors that may predict the aggressive course.

Ulcerative colitis in smokers, non-smokers and ex-smokers

Smoking is a major environmental factor that interferes in the establishment and clinical course of ulcerative colitis (UC). Firstly, the risk of smoking status impact in the development of UC is reviewed, showing that current smoking has a protective association with UC. Similarly, being a former smoker is associated with an increased risk of UC. The concept that smoking could have a role in determining the inflammatory bowel disease phenotype is also discussed. Gender may also be considered, as current smoking delays disease onset in men but not in women. No clear conclusions can be driven from the studies trying to clarify whether childhood passive smoking or prenatal smoke exposure have an influence on the development of UC, mainly due to methodology flaws. The influence of smoking on disease course is the second aspect analysed. Some studies show a disease course more benign in smokers that in non-smokers, with lower hospitalizations rates, less flare-ups, lower use of oral steroids and even less risk of proximal extension. This is not verified by some other studies. Similarly, the rate of colectomy does not seem to be determined by the smoking status of the patient. The third issue reviewed is the use of nicotine as a therapeutic agent. The place of nicotine in the treatment of UC is unclear, although it could be useful in selected cases, particularly in recent ex-smokers with moderate but refractory attacks of UC. Finally, the effect of smoking cessation in UC patients is summarised. Given that smoking represents a major worldwide cause of death, for inpatients with UC the risks of smoking far outweigh any possible benefit. Thus, physicians should advise, encourage and assist UC patients who smoke to quit.

Smoking and inflammatory bowel diseases: what in smoking alters the course?

Epidemiological studies provide strong evidence to confirm the correlation between cigarette smoking and inflammatory bowel diseases. This relationship is proved to be positive in Crohn's disease and negative in ulcerative colitis. What in smoking alters the course of inflammatory bowel diseases is still a mystery. Different smoking parts have different and may be opponent actions. Smoking has dual effects. Some of its activities are, sometimes, constructive as they are working in an antagonistic manner to the mechanism of the disease, such as reducing rectal blood flow and accordingly less recruitments of inflammatory mediators to the area of inflammation, enhancement of mucosal production, and consequently, strengthening the membranes, and inhibition of pro-inflammatory mediators' liberation and activity in subjects with ulcerative colitis. Yet the outcome of smoking actions may be affected by the existence of other cofactors. Odd factors, such as shortage of zinc in subjects with Crohn's disease, may facilitate liberation of pro-inflammatory mediators and their activities and accordingly exacerbates symptoms.

Smoking in inflammatory bowel diseases: good, bad or ugly?

Smoking is an important environmental factor in inflammatory bowel disease (IBD), having different effects in ulcerative colitis (UC) and Crohn's disease (CD). A recent meta-analysis partially confirmed previous findings that smoking was found to be protective against ulcerative colitis and, after onset of the disease, might improve its course, decreasing the need for colectomy. However, smoking increases the risk of developing CD and worsens its course, increasing the need for steroids, immunosuppressants and re-operations. Smoking cessation aggravates ulcerative colitis and improves CD. Data are however, largely conflictive as well as the potential mechanisms involved in this dual relationship are still unknown. In this review article, the authors review the role of smoking in inflammatory bowel diseases.

Smoking in inflammatory bowel diseases: Good, bad or ugly?

Smoking is an important environmental factor in inflammatory bowel disease (IBD), having different effects in ulcerative colitis (UC) and Crohn’s disease (CD). A recent meta-analysis partially confirmed previous findings that smoking was found to be protective against ulcerative colitis and, after onset of the disease, might improve its course, decreasing the need for colectomy. However, smoking increases the risk of developing Crohn’s disease and worsens its course, increasing the need for steroids, immunosuppressants and re-operations. Smoking cessation aggravates ulcerative colitis and improves Crohn’s disease. Data are however, largely conflictive as well as the potential mechanisms involved in this dual relationship are still unknown. In this review article, the authors review the role of smoking in inflammatory bowel diseases.

Appendectomy, smoking habits and the risk of developing ulcerative colitis: a case control study in private practice setting

OBJECTIVES

The strongest environmental factors identified for ulcerative colitis (UC) are cigarette smoking and appendectomy. However, most studies have been performed using case-controls from hospital-based populations. The purpose of this study was to compare the history of previous appendectomy and smoking habits in a group of patients with UC and a control group, followed by gastroenterologists in private practice.

METHODS

We performed a case control study in which 100 physicians recruited UC-patients and age and sex matched controls. Data were collected during a single visit. Based on a standardized questionnaire, UC patients and controls were divided into never, former or current smokers, and into subjects with or without a previous history of appendectomy.

RESULTS

One hundred and ninety eight age- and sex-matched pairs of UC patients and controls were included. The prevalence of appendectomy in the UC-patients and control group was 12% and 46%, respectively. The pairwise-matched OR of ulcerative colitis for previous appendectomy was 0.10 (95% CI, 0.05-0.21) (P<0.0001). The OR for former and never smokers versus current smokers was 2.40 (95% CI 1.31-4.38) (P=0.004). In UC-patients, the OR of family history of UC compared with controls was 2.80 (95% CI, 1.01-7.77) (P=0.048).

CONCLUSIONS

This case-control study confirmed a strong negative correlation between both appendectomy and tobacco smoking, and ulcerative colitis in patients followed-up by gastroenterological practitioners.

The effect of nicotine in vitro on the integrity of tight junctions in Caco-2 cell monolayers

Ulcerative colitis is characterised by impairment of the epithelial barrier and tight junction alterations resulting in increased intestinal permeability. UC is less common in smokers with smoking reported to decrease paracellular permeability. The aim of this study was thus to determine the effect of nicotine, the major constituent in cigarettes and its metabolites on the integrity of tight junctions in Caco-2 cell monolayers. The integrity of Caco-2 tight junctions was analysed by measuring the transepithelial electrical resistance (TER) and by tracing the flux of the fluorescent marker fluorescein, after treatment with various concentrations of nicotine or nicotine metabolites over 48 h. TER was significantly higher compared to the control for all concentrations of nicotine 0.01-10 microM at 48 h (p<0.001), and for 0.01 microM (p<0.001) and 0.1 microM and 10 microM nicotine (p < 0.01) at 12 and 24 h. The fluorescein flux results supported those of the TER assay. TER readings for all nicotine metabolites tested were also higher at 24 and 48 h only (p < or = 0.01). Western blot analysis demonstrated that nicotine up-regulated the expression of the tight junction proteins occludin and claudin-1 (p < or = 0.01). Overall, it appears that nicotine and its metabolites, at concentrations corresponding to those reported in the blood of smokers, can significantly improve tight junction integrity, and thus, decrease epithelial gut permeability. We have shown that in vitro, nicotine appears more potent than its metabolites in decreasing epithelial gut permeability. We speculate that this enhanced gut barrier may be the result of increased expression of claudin-1 and occludin proteins, which are associated with the formation of tight junctions. These findings may help explain the mechanism of action of nicotine treatment and indeed smoking in reducing epithelial gut permeability.

Preliminary observations of oral nicotine therapy for inflammatory bowel disease: an open-label phase I-II study of tolerance

BACKGROUND

Transdermal nicotine provides benefit in active ulcerative colitis but is often associated with adverse events (AEs). An oral formulation has been developed to minimize AEs. This study was undertaken to make initial observations on the safety and tolerance of oral nicotine therapy in inflammatory bowel disease; the effect on disease activity was also noted.

METHODS

Twenty-six patients with ulcerative colitis, 11 with active disease, and 5 patients with Crohn's colitis (2 with active disease) were given oral nicotine in 3-mg capsules, gradually increasing the dose to the maximum tolerated. AEs were recorded, concomitant prednisolone and/or azathioprine were reduced where possible, and disease activity was reassessed at the end of nicotine treatment.

RESULTS

Patients were followed for up to 12 months. Twenty-nine of 31 could tolerate at least 6 mg of nicotine each day, and 5 patients tolerated at least 18 mg daily. Twenty-four patients had nicotine-related nonserious AEs; over one half occurred during the period of dose escalation, but 7 discontinued treatment because of them. Six of the 13 patients with active disease became asymptomatic, whereas 3 patients in remission developed active symptoms; 11 patients reduced their concomitant medication.

CONCLUSIONS

Oral nicotine is a safe potential treatment of inflammatory bowel disease, but there is considerable variation in tolerance.

A randomized trial of nicotine enemas for active ulcerative colitis

BACKGROUND & AIMS

Ulcerative colitis (UC) is largely a disease of nonsmokers in which transdermal nicotine improves the symptoms but often causes adverse events (AEs). Nicotine enemas cause fewer AEs and were used as supplemental treatment for active UC.

METHODS

We treated 104 patients with active UC with either 6-mg nicotine enemas or placebo enemas for 6 weeks in a randomized double-blind study. Patients continued their oral therapy, if any, for UC: 68 patients were taking mesalamine, 15 patients were taking prednisolone, and 12 patients were taking thiopurines during the study. Clinical, sigmoidoscopic, and histologic assessments were made at baseline and at the end of the study and symptoms were recorded daily on a diary card. The primary end point was induction of clinical remission and clinical improvement also was measured by the UC disease activity index. After the study, patients then used nicotine enemas daily for 4 weeks and sigmoidoscopy with a biopsy examination was repeated. AEs and salivary cotinine levels were monitored throughout the study.

RESULTS

Clinical remission was achieved in 14 of 52 (27%) patients on active treatment and 14 of 43 (33%) patients on placebo (P = .55). The UC disease activity index improved by 1.45 points in the active group and by 1.65 points for those on placebo (P = .88). Only 1 patient discontinued treatment because of an AE (abdominal pain). In the 47 patients taking mesalamine only, active treatment conferred benefit that was not statistically significant; disease remission occurred in 9 of 25 patients on active therapy and 4 of 21 patients on placebo (P = .20).

CONCLUSIONS

Six-milligram nicotine enemas were well tolerated but were not found to be efficacious for active UC.

The pharmacological actions of nicotine on the gastrointestinal tract

Increasing use of tobacco and its related health problems are a great concern in the world. Recent epidemiological findings have demonstrated the positive association between cigarette smoking and several gastrointestinal (GI) diseases, including peptic ulcer and cancers. Interestingly, smoking also modifies the disease course of ulcerative colitis (UC). Nicotine, a major component of cigarette smoke, seems to mediate some of the actions of cigarette smoking on the pathogenesis of GI disorders. Nicotine worsens the detrimental effects of aggressive factors and attenuates the protective actions of defensive factors in the processes of development and repair of gastric ulceration. Nicotine also takes part in the initiation and promotion of carcinogenesis in the GI tract. In this regard, nicotine and its metabolites are found to be mutagenic and have the ability to modulate cell proliferation, apoptosis, and angiogenesis during tumoriogenesis through specific receptors and signalling pathways. However, to elucidate this complex pathogenic mechanism, further study at the molecular level is warranted. In contrast, findings of clinical trials give promising results on the use of nicotine as an adjuvant therapy for UC. The beneficial effect of nicotine on UC seems to be mediated through multiple mechanisms. More clinical studies are needed to establish the therapeutic value of nicotine in this disease.

Metabolism and biochemical effects of nicotine for primary care providers

Nicotine is a colorless and volatile liquid alkaloid naturally occurring in the leaves and stems of Nicotiana tabacum and Nicotiana rustica. Nicotine, the primary component of tobacco, is responsible for both tobacco product addiction (with chronic exposure) and the odor associated with tobacco. In addition to cigarettes, nicotine is found in chewing gum, transdermal patches, nasal spray, and sublingual tablets. Following its inhalation and absorption, nicotine and its metabolic products exert diverse physiologic and pharmacologic effects. This article covers the absorption and metabolism of nicotine, nicotine toxicity, pharmacologic effects of nicotine, nicotine-drug interactions, and the use of nicotine for the treatment of disease.

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.

Nicotine enemas for treatment of ulcerative colitis: a study of the pharmacokinetics and adverse events associated with three doses of nicotine

BACKGROUND

Transdermal nicotine is of value in active ulcerative colitis but causes adverse events because of systemic absorption. Nicotine enemas may give rise to fewer adverse events.

AIM

To assess the pharmacokinetics of nicotine enemas in three doses.

METHODS

Thirteen volunteers, all non-smokers but three ex-smokers, were given enemas on separate occasions containing 3, 6 and 9 mg of nicotine, in ascending dose order. Adverse events were recorded and blood samples taken over 8 h for measurement of serum nicotine and cotinine.

RESULTS

Enemas were retained by most subjects. Eleven of 14 adverse events were 'early'--30-105 min after the enema, corresponding to maximum plasma nicotine concentrations; three events were later, 4-8 h after the enema and unrelated to the tmax. 'Early' adverse events occurred in eight subjects--six with 9 mg. The three highest plasma nicotine concentrations were with 9 mg and associated with headache, nausea and sweating. Only one had adverse events with 3 mg and withdrew from the study. Nicotine Cmax with 6 and 9 mg doses were respectively two and three times the value with 3 mg. Peak nicotine concentrations occurred 44-50 min after the enema.

CONCLUSION

The 6 mg dose of nicotine probably represents the dose to use in clinical practice - for the highest therapeutic dose with a low risk of adverse events.

Management of refractory inflammatory bowel disease

One of the most challenging aspects of the management of inflammatory bowel disease is the high frequency of incomplete or absent response to medical therapy. Although many patients may be truly refractory to medical therapy, a lack of response may indicate several possibilities, including incorrect diagnosis, progression of disease extent, intestinal complication, superinfection, underdosing of therapy, monotherapy instead of combination therapy, or medication intolerance. This article provides a practical general approach to refractory inflammatory bowel disease patients encountered in clinical practice.

Clinical epidemiology of inflammatory bowel disease: Incidence, prevalence, and environmental influences

Although the incidence and prevalence of ulcerative colitis and Crohn's disease are beginning to stabilize in high-incidence areas such as northern Europe and North America, they continue to rise in low-incidence areas such as southern Europe, Asia, and much of the developing world. As many as 1.4 million persons in the United States and 2.2 million persons in Europe suffer from these diseases. Previously noted racial and ethnic differences seem to be narrowing. Differences in incidence across age, time, and geographic region suggest that environmental factors significantly modify the expression of Crohn's disease and ulcerative colitis. The strongest environmental factors identified are cigarette smoking and appendectomy. Whether other factors such as diet, oral contraceptives, perinatal/childhood infections, or atypical mycobacterial infections play a role in expression of inflammatory bowel disease remains unclear. Additional epidemiologic studies to define better the burden of illness, explore the mechanism of association with environmental factors, and identify new risk factors are needed.

Cigarette smoking and appendectomy are risk factors for extraintestinal manifestations in ulcerative colitis

OBJECTIVE

Two common factors, cigarette smoking and appendectomy, have been found to play a role in ulcerative colitis (UC). Data on their role in the development of extraintestinal manifestations (EIM) are scarce.

METHODS

The relationship between cigarette smoking, appendectomy, and EIM was examined in a prospective study involving 535 (M/F = 319/216) consecutive UC patients followed up for 18 yr. We considered the major EIM: seronegative spondyloarthropathy, pyoderma gangrenosum/erythema nodosum, acute anterior uveitis, and primary sclerosing cholangitis. We excluded patients with a history of EIM or those colectomized before study entry, ex-smokers, and those who started to smoke during the course of UC.

RESULTS

In UC patients, seronegative spondyloarthropathy and dermatologic complications were found increased in smokers (p < 0.0001; p = 0.001) or in subjects with appendectomy (p = 0.0003; p = 0.02), while acute anterior uveitis and primary sclerosing cholangitis did not differ. The Kaplan-Meier analysis showed 18-yr rates for EIM of 71% in smokers and 45% in nonsmokers (log-rank test, p = 0.0001), and of 85% in patients with appendectomy and 48% in those without (p = 0.0001). Cox proportional-hazard model showed that cigarette smoking and appendectomy are independent factors promoting EIM. In smokers with appendectomy the adjusted hazard ratio (3.197, 95% CI 1.529-6.684) was higher than in patients with appendectomy alone (2.617, 95% CI 1.542-4.442) or smoking alone (1.947, 95% CI 1.317-2.879).

CONCLUSIONS

In UC patients, appendectomy and cigarette smoking are prognostic factors for the development of EIM. The unfavorable effect of cigarette smoking on EIM is additive to that of appendectomy.

A double-blind comparison of balsalazide, 6.75 g, and sulfasalazine, 3 g, as sole therapy in the management of ulcerative colitis

BACKGROUND

Sulfasalazine is accepted therapy for active ulcerative colitis, but side-effects and intolerance are common. Balsalazide is an azo-bonded pro-drug which also releases 5-aminosalicylic acid into the colon, but uses an inert carrier molecule.

AIM

To compare the safety and efficacy of sul- fasalazine, 3 g, with balsalazide, 6.75 g, in the initial daily treatment of mild to moderate ulcerative colitis.

METHODS

A randomized, multicentre, double-blind, parallel group study was performed, with a treatment duration of 8 weeks. Patients on previous maintenance treatment were excluded. The trial medication was the sole treatment for the colitis. Efficacy was assessed by patient diaries, symptom assessment, sigmoidoscopic appearance and histology.

RESULTS

Fifty patients were recruited: 26 allocated to the balsalazide group and 24 to the sulfasalazine group. More patients withdrew due to adverse events in the sulfasalazine group (nine patients vs. one patient in the balsalazide group, P=0.004). Improvement occurred in both groups, with a tendency to a faster response with balsalazide. Of the patients taking balsalazide, 61% achieved clinical and sigmoidoscopic remission.

CONCLUSIONS

Balsalazide, 6.75 g, is effective as the sole treatment for patients with mild to moderately active ulcerative colitis, with significantly fewer withdrawals due to side-effects than in a similar group of patients taking sulfasalazine, 3 g.

Impact of cessation of smoking on the course of ulcerative colitis

OBJECTIVES

The incidence and severity of ulcerative colitis (UC) are higher in nonsmokers than in smokers. The natural course of UC in smokers who stop smoking is not known. The aim of this study was to determine the impact of cessation of smoking on the course of UC among the cohort of patients regularly seen at our institution.

METHODS

The severity of UC, as judged by the occurrence of flare-ups and the need for systemic steroids, immunosuppressive drugs and colectomy, was determined in 32 patients with UC who stopped smoking after the diagnosis of UC. We compared the period after cessation of smoking (7-yr mean follow-up) with the period between the onset of the disease and the cessation of smoking (9-yr mean duration). The course of UC in this group was compared with that of 32 nonsmokers and 32 continuing smokers matched for sex, age, and age at onset.

RESULTS

In patients who quit, cessation of smoking was followed by an increase in the rate of years with active disease (p < 0.01), years with hospitalization (p < 0.05) and years with major medical therapy (oral steroids, intravenous steroids, and azathioprine, p < 0.01). After cessation of smoking, the rate of years with immunosuppressive therapy was significantly greater in ex-smokers and nonsmokers than in continuing smokers (p < 0.01). The risk of colectomy in ex-smokers after smoking cessation was similar to that of nonsmokers and continuing smokers.

CONCLUSIONS

In smokers with UC who stop smoking, the severity of the disease increases after smoking cessation, with an increase in the disease activity and the need for hospital admission and major medical therapy. In addition, the need for azathioprine therapy becomes similar to that of nonsmokers.

Role of smoking in inflammatory bowel disease: implications for therapy

The relationship between smoking and inflammatory bowel disease is now firmly established but remains a source of confusion among both patients and doctors. It is negatively associated with ulcerative colitis but positively associated with Crohn's disease. In addition, it has opposite influences on the clinical course of the two conditions with benefit in ulcerative colitis but a detrimental effect in Crohn's disease. These differences have been the subject of much interest and scrutiny with the hope that they may offer some insight into the pathogenesis of the two conditions and possibly lead to alternative therapeutic options. Nicotine is probably the principal active ingredient in smoking responsible for the association; trials have shown it to be of some benefit in ulcerative colitis, but further research is required to establish its therapeutic role, and the relevant mechanisms responsible for its action. In this article, we review the role of smoking in inflammatory bowel disease and its implication for therapy.

Lack of association between smoking and Crohn's disease but the usual association with ulcerative colitis in Jewish patients in Israel: a multicenter study

OBJECTIVE

The association between smoking and inflammatory bowel disease (IBD) is well established, but data in Jewish patients in Israel were discrepant. The aim of this study was to examine the smoking habits of Jewish IBD patients in Israel in a large scale, multicenter study.

METHODS

Patients with established IBD aged 18-70 yr were interviewed in relation to smoking and other habits. Two controls (one clinic and one neighborhood control matched by age, sex, community group, and education) were sought for each subject.

RESULTS

A total of 534 patients (273 ulcerative colitis [UC], and 261 Crohn's disease [CD]), along with 478 clinic controls and 430 neighborhood controls, were interviewed. There was no significant difference in the smoking habits between CD patients and their controls. Of patients with CD, 24.5% were current smokers, as compared to 19.9% of clinic controls and 25.2% of neighborhood controls (NS). The odds ratio for CD in current smokers was 1.30 (95% confidence interval 0.85-1.99) versus clinic controls, and 0.96 (0.63-1.46) versus neighborhood controls. There were also no significant differences in the proportion of ex-smokers between the groups. Only 12.9% of UC patients were current smokers versus 21.9. % Clinic controls, and 26.4% community controls (p<0.005). The proportions of ex-smokers were higher in UC patients 29.7% versus 25.9%, and 19.5% in their respective controls (p<0.001 vs. community controls). No significant differences were found in the proportions of never-smokers between IBD patients and controls. All the above trends were similar in four different parts of the country. The proportion of current smokers in UC decreased with the extent of disease (19.7% in proctitis, 13.6% in left-sided, and 4.5% in total colitis) (p<0.05). Patients with UC were more likely to be light smokers(1-10 cigarettes/day), whereas patients with CD were more likely to be moderate smokers (11-20 cigarettes/day) in comparison to their controls.

CONCLUSIONS

The lack of association between smoking and CD has now been established in Jewish patients in Israel. The association was found in UC. The stronger genetic tendency in CD may contribute to this discrepancy.

Cigarette smoke aggravates experimental colitis in rats

BACKGROUND & AIMS

Tobacco smoking has a complex effect on intestinal inflammation, being protective in ulcerative colitis, whereas it aggravates Crohn's disease. The beneficial effect of smoking has been attributed to nicotine, but the mechanisms underlying the adverse effect are still under investigation. The aim of this study was to examine the effect of cigarette smoking on experimental colitis in rats and to investigate the underlying mechanism.

METHODS

Rats were exposed daily to cigarette smoke by means of a specialized smoking chamber. Control rats were placed in the same chamber without introducing smoke. In parallel experiments, rats received the ganglionic blocker hexamethonium before smoke exposure. After 2 weeks, colitis was induced by dinitrobenzenesulfonic acid (DNBS), and inflammation was assessed 3 days later.

RESULTS

Exposure to cigarette smoke significantly increased macroscopic and histological damages as well as myeloperoxidase activity compared with sham-treated controls. Treatment with hexamethonium before smoking reversed the effect of the smoke on the colitis, improving all parameters.

CONCLUSIONS

Exposure to cigarette smoke aggravates DNBS-induced colitis in the rat. This effect is reversed by hexamethonium, suggesting that a neural pathway is involved.

An oral formulation of nicotine for release and absorption in the colon: its development and pharmacokinetics

AIMS

Ulcerative colitis is predominantly a disease of nonsmokers and transdermal nicotine has therapeutic value in active disease; however side-effects are troublesome. The aim of this study was to develop an oral formulation of nicotine which would be slowly released in the colon over 6 h, and to examine its pharmacokinetic profile in 12 healthy volunteers, with measurements of serum nicotine and cotinine, its principal metabolite.

METHODS

Nicotine was combined with a polyacrylic carbomer, Carbopol 974P which was incorporated into 13 different vehicles and their release profiles examined in vitro. The polyglycolized glyceride, Gelucire 50/13, was chosen for subsequent kinetic studies because it consistently produced a suitable release pattern which was linear. Capsules containing 3 mg nicotine, combined with carbomer in Gelucire 50/13, were coated with an acrylic resin Eudragit L; this ensured the capsule would remain intact until the ileum. On 2 separate days, 6 and 15 mg nicotine, contained in 2 and 5 capsules, respectively, were administered to 12 subjects, all nonsmokers, mean age 28 years. Serial blood measurements were taken for 36 h, serum nicotine and cotinine concentrations were measured by gas liquid chromatography.

RESULTS

There was considerable intersubject variability in the nicotine and cotinine values. Plasma nicotine levels began to rise about 4 h after ingestion of the capsules, corresponding with the oro-caecal transit time. Cmax nicotine values were 2.2 and 5 ng ml-1, obtained 7 h after the ingestion of 6 and 15 mg, respectively, of the formulation. The corresponding Cmax values for cotinine were 37 and 94.4 ng ml-1, occurring after 9-10 h. The mean for elimination half-lives in the 24 studies, including the 6 and 15 mg doses, for nicotine were 4.3+/-2.7 h and for cotinine 16.8+/-7.5 h. With 6 mg nicotine-carbomer, only 1 of 12 volunteers had possible side-effects, but with the 15 mg dose 11 out of the 12 reported adverse effects which were systemic or gastrointestinal in nature-their timing corresponded with peak serum concentrations of nicotine.

CONCLUSIONS

An oral formulation of nicotine has been developed; in the ileum and colon, this becomes available for slow linear release over 6 h and delivers high concentrations of nicotine for topical effect on the colon. 6 mg Nicotine was well tolerated, whilst 15 mg gave both systemic and gastrointestinal side-effects. High concentrations of topical nicotine in the colon are achieved with relatively low systemic bioavailablity-reflected by the Cmax and AUC values for nicotine. This, or comparable formulations, may be of therapeutic value in ulcerative colitis.

Transdermal nicotine decreases mucosal IL-8 expression but has no effect on mucin gene expression in ulcerative colitis

Our goal was to determine the effect of transdermal nicotine on cytokine and mucin gene transcription in ulcerative colitis (UC). Sixty-four nonsmoking patients with active UC were randomly assigned to transdermal nicotine (maximum dose 22 mg/day) or placebo for 4 weeks. Clinical assessment and colonic mucosal biopsies were obtained at entry and after 4 weeks. Inflammatory and immunoregulatory cytokines were assessed by qualitative reverse transcriptase-polymerase chain reaction (RT-PCR). Based on this initial screen. IL-8 mRNA levels were measured by RT-competitive PCR. MUC1, MUC2, MUC3, MUC4, MUC5AC, MUC5B, and MUC6 mRNA concentrations were measured by quantitative dot blot analysis. Cytokine mRNA expression, except for IL-8, was similar in all patients. IL-8 mRNA levels were significantly decreased in the colonic mucosa of nicotine-treated patients who improved (p = 0.04). IL-8 mRNA values were similar before and after treatment in nonresponding nicotine-treated patients and in all placebo-treated patients. Mucin gene expression was similar in all patient groups. Beneficial effects of transdermal nicotine in active UC may result from decrease of IL-8 expression at the transcriptional level. Transdermal nicotine has no effect on mucin gene transcription.

Nicotine therapy for ulcerative colitis: a review of rationale, mechanisms, pharmacology, and clinical results

Smoking is protective against developing ulcerative colitis. Nicotine may be the cause of this protective effect. Controlled trials have demonstrated efficacy of transdermal nicotine for active ulcerative colitis. Side effects observed with transdermal nicotine include contact dermatitis, nausea, and lightheadedness. Topical administration of nicotine to the colon reduces nicotine blood concentrations and side effects, and may be of clinical benefit.

Clinical status of ulcerative colitis in patients who smoke

OBJECTIVES

Ulcerative colitis (UC) is largely a disease of nonsmokers. There are few patients who are current smokers, but we have identified a group and reviewed their clinical status, disease activity, and nicotine exposure to examine whether they remain well controlled while smoking.

METHODS

Fifty-one patients from three centers with verified UC were reviewed.

RESULTS

Thirty of the group were men; mean age 50 yr, with a mean age of onset of 37 yr. Twenty-two patients had proctosigmoid disease, 12 involvement of left colon, and 17 total colitis. All were current smokers; 41 were cigarette smokers averaging 17 daily. At the onset of colitis 30 were nonsmokers, 25 of them were ex-smokers and 19 developed colitis within 2 yr of stopping smoking. Twenty-eight believed smoking improved disease activity and none felt smoking had a detrimental effect on their UC. Eleven were receiving no medication for UC, 40 were receiving 5-ASA (5-aminosalicylic acid) preparations, and only two took oral steroids. All were in clinical remission, with the exception of one patient; mean St. Marks score was 1.5, out of a possible total of 22. Sigmoidoscopic grades were inactive in all patients except three. Histological assessment showed significant activity in only five. Median serum nicotine was 8 ng/ml (range, 0.4-24.4), median serum cotinine 180 ng/ml (range, 20-453), with corresponding salivary cotinine of 255 ng/ml (range, 34-683). Median rise in nicotine 2 min after a cigarette in 35 patients was 12.1 ng/ml (range, 0.4-44).

CONCLUSIONS

Because most current smokers with UC have inactive disease, smoking may contribute to the clinical remission in these patients.

Inflammatory bowel disease and smoking--a review

The relationship between smoking and inflammatory bowel disease is a curious but well-established one. It is negatively associated with ulcerative colitis but positively associated with Crohn's disease. It also has opposite influences on the clinical course of the two conditions with possible beneficial effect in ulcerative colitis and detrimental effect in Crohn's disease. The diametrically "opposite" relationship of smoking status with the two conditions has been the subject of much interest in the hope that it may reveal pathogenic mechanisms responsible for the two conditions and possibly offer the key to alternative therapeutic options. Nicotine may be the principal agent in smoking responsible for the association; trials have shown it to be of some benefit in ulcerative colitis, but further research is required to establish its therapeutic role and possible mechanisms of action. In this article, we review the historical, clinical, and therapeutic aspects of the association between smoking and inflammatory bowel disease.

Nicotine tartrate liquid enemas for mildly to moderately active left-sided ulcerative colitis unresponsive to first-line therapy: a pilot study

BACKGROUND

Ulcerative colitis is predominantly a disease of non-smokers, and transdermal nicotine is therapeutic but often results in side-effects. Administration of nicotine as a liquid rectal enema results in less systemic nicotine absorption.

AIM

To determine the safety and clinical response of nicotine tartrate liquid enemas for active left-side ulcerative colitis in a pilot study.

METHODS

Ten non-smoking patients with mildly to moderately active left-sided ulcerative colitis unresponsive to first-line therapy were treated in an open protocol with nightly nicotine tartrate liquid enemas at a dose of 3 mg nicotine base for 1 week then 6 mg for 3 weeks. Clinical assessments were determined at baseline and 4 weeks by endoscopy, physician assessment and a patient diary of daily symptoms. Peak and trough serum nicotine and trough plasma cotinine were determined by gas chromatography/mass spectrometry and high performance liquid chromatography, respectively.

RESULTS

After 4 weeks of treatment, 5/7 patients (71%) showed clinical and sigmoidoscopic improvement (per protocol analysis). The other three patients discontinued therapy within 7 days because of inability to retain the liquid enemas. No patients showed histologic improvement. Six of the patients who completed the 4-week study had peak and trough serum nicotine concentration determined, only 1 of 6 patients had a detectable peak nicotine concentration (value 2.3 ng/mL), and all six patients had undetectable trough nicotine concentrations. The mean trough plasma cotinine concentration was 13 +/- 10 ng/mL. Transient and mild adverse events occurred in 4/10 patients (nausea, lightheadedness, tremor, sleep disturbance). Given the low or undetectable serum nicotine concentrations, these adverse events are not likely to be related to the nicotine enemas.

CONCLUSIONS

Nicotine tartrate liquid enemas administrated at a dose of 3 mg nicotine base/day for 1 week and then 6 mg/day for 3 weeks are safe and appear to result in clinical improvement in some patients with mildly to moderately active, left-sided ulcerative colitis unresponsive to first-line therapy. Placebo-controlled trials are warranted to confirm these preliminary findings.

Pharmacokinetics of nicotine tartrate after single-dose liquid enema, oral, and intravenous administration

Ulcerative colitis is predominantly a disease of nonsmokers, and transdermal nicotine is therapeutic but often results in adverse reactions. Colonic administration of nicotine tartrate as a liquid enema could decrease systemic nicotine absorption and adverse reactions. The purpose of the current study was to determine the bioavailability and pharmacokinetic parameters of nicotine after administration by hydrophilic liquid enema (acidic and basic), hydrophobic liquid enema (acidic and basic), and by oral and intravenous routes. Thirty healthy volunteers received 45 micrograms nicotine base/kg (as nicotine tartrate) in one of five formulations (each n = 6): hydrophilic acidic liquid enema, hydrophilic basic liquid enema, hydrophobic acidic liquid enema, hydrophobic basic liquid enema, and oral solution. All participants also received 15 micrograms nicotine base/kg (as nicotine tartrate) intravenously during a separate study period. Serum concentrations of nicotine were determined by gas chromatography with mass spectrometry. The mean (+/-SD) bioavailabilities of nicotine after administration in the liquid enema formulations (hydrophilic acidic 17 +/- 18%, hydrophilic basic 16 +/- 16%, hydrophobic acidic 25 +/- 17%, hydrophobic basic 15 +/- 12%) were similar to the bioavailability of nicotine after administration by oral solution (20 +/- 25%). The bioavailabilities of nicotine for all five nonintravenous formulations were significantly less than for intravenous nicotine (100%). Serum concentrations of nicotine did not predict adverse reactions. Nicotine tartrate administered as either a liquid enema or as an oral solution had low bioavailability and was well tolerated. The therapeutic potential of nicotine tartrate liquid enemas, which can potentially limit toxicity by local (colonic) delivery of high doses of nicotine should be investigated in patients with left-sided ulcerative colitis.

Pharmacokinetics of nicotine carbomer enemas: a new treatment modality for ulcerative colitis

BACKGROUND

Ulcerative colitis is largely a disease of nonsmokers, and transdermal nicotine is of therapeutic value in the active disease. Because side effects are common, we developed a topical enema formulation of nicotine.

OBJECTIVE

To study the pharmacokinetics of nicotine complexed with a polyacrylic carbomer and administered by enema to eight healthy volunteers and to eight patients with active ulcerative colitis, verified sigmoidoscopically.

PATIENTS AND METHODS

All 16 subjects were nonsmokers. The mean age for normal subjects was 33 years; the mean for patients with ulcerative colitis was 60 years. Median stool frequency for patients with ulcerative colitis was four daily. Patients were taking 5-amino salicylic acid compounds and five were taking oral prednisolone (median dose, 12 mg daily). Nicotine, 6 mg, complexed with carbomer 974P, 400 mg, was administered in a 100 ml enema after an overnight fast, with serial blood measurements taken over 8 hours. Serum nicotine and cotinine were measured by gas liquid chromatography. Area under the concentration-time curves were calculated by the trapezoidal method, and the terminal elimination half-life was derived by extrapolation of the log-linear terminal phase.

RESULTS

With the exception of nicotine time to reach peak concentration, which was longer in patients (median of 60 minutes compared with 45 minutes; p < 0.005), other comparisons between normal subjects and patients showed no statistically significant difference, although there was considerable inter-subject variation. Maximum concentration of nicotine, 8.1 +/- 3.5 ng/ml, in the 16 subjects occurred after a median of 60 minutes (range, 30 to 180 minutes); maximum cotinine concentrations of 60.4 +/- 11.5 ng/ml occurred after 4 hours. Side effects in five subjects were mild (four subjects) or moderate (one subject) and included lightheadedness, nausea, and headache; these five subjects were female lifelong nonsmokers of low body weight.

CONCLUSION

Because most of the active ingredient of nicotine is converted to continine on the first pass through the liver, substantial concentrations can be achieved at the site of disease with only modest rises in serum nicotine, which are responsible for side effects; cotinine has low pharmacologic activity. Topical administration of nicotine may be useful treatment for distal ulcerative colitis.

The role of cigarettes and nicotine in the onset and treatment of ulcerative colitis

Epidemiological evidence suggests that ulcerative colitis is a disease of nonsmokers, while Crohn's disease is a disease of smokers. The relative risk of developing ulcerative colitis is not only greater in nonsmokers, in addition there appears to be a rebound effect in smokers who quit, with the heaviest (ex-)smokers increasing their relative risk of the disease the most. This factor poses an ethical dilemma for health professionals giving advice on stopping smoking, which may thus have a serious detrimental effect on the health of some patients. Nicotine is believed to be the pharmacological ingredient of tobacco that is responsible for this beneficial effect and several clinical trials using nicotine have demonstrated it to be an effective therapeutic agent in the treatment of ulcerative colitis. Although the aetiology of ulcerative colitis is unclear, current research using nicotine-based products has produced some interesting clues, together with the possibility of some form of therapeutic treatment based on nicotine administration.

Pilot trial of nicotine patches as an alternative to corticosteroids in ulcerative colitis

In ten patients with mild to moderate clinical relapses of ulcerative colitis during treatment with mesalazine (1 g t.i.d.) and with a previous history of poorly tolerated steroid courses, transdermal nicotine (15 mg daily) was added for 4 weeks. Clinical findings were assessed by employing Rachmilewitz's activity index. In 7 of the patients, clinical remission was achieved, the results persisting for up to 3 months after nicotine withdrawal. Endoscopic and histological examination, when performed, confirmed the clinical findings. Nicotine patches may represent a good alternative to steroids in selected patients with mild to moderate relapses of ulcerative colitis. The precise mechanism of action remains unknown.

Review article: refractory distal colitis -- explanations and options

Distal colitis refractory to standard therapy is a complex and challenging problem. Physiological differences between the right and left colon may be exploited for maximum therapeutic benefit. Over-reliance on oral therapy should be seen as one of the reasons for treatment failure and delivery systems should target therapy to the distribution of the disease in doses proven to be therapeutically beneficial. The clinician should also be cognizant of potential adverse effects of standard therapies, particularly colitis due to mesalazine, which may mimic worsening disease. Numerous endogenous and exogenous factors that may exacerbate the underlying inflammatory bowel disease are discussed. This review explores the potential mechanisms why distal colitis may be refractory to therapy and addresses newer therapies that, while still in the investigatory stages, offer hope for a widening armamentarium of therapeutic modalities.

Transdermal nicotine as maintenance therapy for ulcerative colitis

BACKGROUND

Ulcerative colitis is largely a disease of nonsmokers. Having found previously that treatment with transdermal nicotine patches and mesalamine (5-aminosalicylic acid) has a beneficial effect on active colitis, we examined the value of transdermal nicotine for the maintenance of remission.

METHODS

We treated 80 patients with ulcerative colitis in remission with either transdermal nicotine or placebo patches for six months in a randomized, double-blind study. Incremental doses of nicotine were given for the first three weeks to achieve a maintenance dose; most patients tolerated 15 mg for 16 hours daily. All patients were taking mesalamine preparations as maintenance treatment at entry into the study; this treatment was stopped once the maintenance dose of nicotine was achieved. Clinical, sigmoidoscopic, and histologic assessments were made at the beginning and the end of the study, or at relapse. Side effects and serum nicotine and cotinine concentrations were monitored throughout the study.

RESULTS

There was no significant difference in the number of relapses between the groups. Twenty-two patients in the nicotine group were prematurely withdrawn from the study, 14 because of relapse and 8 for other reasons, including side effects and protocol violations. In the placebo group, 20 patients were withdrawn prematurely, 17 because of relapse and 3 for other reasons. Among patients using 15-mg nicotine patches, serum nicotine and cotinine concentrations were lower than expected and may reflect poor compliance. Side effects were reported by 35 patients--21 in the nicotine group and 14 in the placebo group--the most common of which were nausea, lightheadedness, and itching.

CONCLUSIONS

Transdermal nicotine alone was no better than placebo in the maintenance of remission of ulcerative colitis, and premature withdrawal due to side effects was more common in the nicotine group.

Transdermal nicotine for active ulcerative colitis

BACKGROUND

Ulcerative colitis is largely a disease of nonsmokers. Because anecdotal reports suggest that smoking and nicotine may improve the symptoms of the disease, we examined the effect of nicotine as a supplemental treatment for ulcerative colitis.

METHODS

We treated 72 patients with active ulcerative colitis with either transdermal nicotine patches or placebo patches for six weeks in a randomized, double-blind study. Incremental doses of nicotine were given; most patients tolerated doses of 15 to 25 mg per 24 hours. All the patients had been taking mesalamine, and 12 were receiving low doses of glucocorticoids; these medications were continued without change during the study. Clinical, sigmoidoscopic, and histologic assessments were made at base line and at the end of the study; symptoms were recorded daily on a diary card, and the clinician made a global assessment. Side effects and plasma nicotine and cotinine concentrations were monitored throughout the study.

RESULTS

Seventeen of the 35 patients in the nicotine group had complete remissions, as compared with 9 of the 37 patients in the placebo group (P = 0.03). The patients in the nicotine group had greater improvement in the global clinical grade of colitis (P < 0.001) and the histologic grade (P = 0.03), lower stool frequency (a difference of 1.6 stools daily; P = 0.008), less abdominal pain (P = 0.05), and less fecal urgency (P = 0.009). More patients in the nicotine group had side effects (23, vs. 11 in the placebo group; P = 0.002), the most common of which were nausea, lightheadedness, headache, and sleep disturbance. Withdrawals due to ineffective therapy were more common in the placebo group (3 vs. 8, P = 0.12).

CONCLUSIONS

The addition of transdermal nicotine to conventional maintenance therapy improves symptoms in patients with ulcerative colitis.

Effect of nicotine on rectal mucus and mucosal eicosanoids

Because ulcerative colitis is largely a disease of non-smokers and nicotine may have a beneficial effect on the disease, the effect of nicotine on rectal mucosa in rabbits was examined. Nicotine was given subcutaneously by an Alzet mini-pump in doses of 0.5, 1.25, and 2 mg/kg/day for 14 days to three groups of eight animals and compared with eight controls. Mean (SD) serum nicotine concentrations (ng/ml) were 3.5 (1.1), 8.8 (2.3), and 16.2 (5.2) respectively in the treated groups. The thickness of adherent mucus on rectal mucosa in controls (median 36 microns) was significantly reduced by low dose (22 microns, p = 0.0011), and increased by high dose nicotine (48 microns, p = 0.035). Incorporation of radioactive glucosamine into papain resistant glycoconjugates was unchanged, indicating that mucin synthesis was unaltered. Prostaglandins (PG) were reduced, in some cases significantly (6-keto PGF1 alpha, PGF2 alpha, and hydroxy-eicosatetraenoic acid), by nicotine, which showed an inverse dose dependence--with greatest inhibition in relation to the lowest dose. Nicotine, and possibly smoking, may affect colitis by an action on mucosal eicosanoids and on adherent surface mucus secretion in the rectum and large bowel.

Smoking and ulcerative colitis: a community study

Smoking habits of patients with ulcerative colitis, diagnosed in the City of Cardiff between the 1st of January 1978 and the 31st of December 1987 were examined. There was a significant deficit of current smokers, an excess of life-long non-smokers and ex-smokers compared with the general population. Men who had previously smoked presented with colitis later than life long non-smokers (mean age difference 16.1 years). The proportion of ex-smokers in this group of patients with colitis was more than twice that expected in the general population. The interval between cessation of smoking and subsequent onset of colitis in ex-smokers was relatively short and in more than half of them occurred within 8 years. There was no significant difference in the frequency of colectomy or the extent of disease among smokers, ex-smokers or life-long non-smokers with ulcerative colitis.