Discontinuous oral absorption of cimetropium bromide, a new antispasmodic drug

Assessment of Cimetropium Bromide Use for the Detection of Gastric Neoplasms During Esophagogastroduodenoscopy

IMPORTANCE

Esophagogastroduodenoscopy (EGD) is a common procedure used to examine upper gastrointestinal diseases. Although cimetropium bromide and other antispasmodic agents are commonly administered as premedication to inhibit peristalsis during EGD examination, there are few data regarding the benefits of cimetropium bromide for the detection of gastric neoplasms.

OBJECTIVE

To investigate the association between the use of cimetropium bromide as premedication and gastric neoplasm detection rates during EGD examination.

DESIGN, SETTING, AND PARTICIPANTS

This propensity score-matched retrospective cohort study included 67 683 participants who received EGD screening at the Health Promotion Center of Seoul St. Mary's Hospital, The Catholic University of Korea, from January 2, 2010, to June 30, 2017. Data were analyzed from April 1 to December 30, 2021.

EXPOSURES

Participants were divided into 2 groups: those who received cimetropium bromide before EGD examination (intervention group) and those who did not (control group).

MAIN OUTCOMES AND MEASURES

Gastric neoplasm detection rates.

RESULTS

Among 67 683 participants, the mean (SD) age was 48.6 (10.8) years, and 36 517 participants (54.0%) were male; all participants were Asian (a racially homogenous population). Of those, 28 280 participants (41.8%; mean [SD] age, 50.3 [10.6] years; 57.8% male) received cimetropium bromide, and 39 403 participants (58.2%; mean [SD] age, 47.4 [10.8] years; 51.2% male) did not. Propensity score matching based on confounding variables yielded 41 670 matched participants (20 835 pairs). Detected lesions included 52 dysplasias (0.12%), 40 early cancers (0.10%), 7 advanced cancers (0.02%), and 3 lymphomas (0.01%). Gastric neoplasm detection rates were significantly higher in the intervention group (63 participants [0.30%]) vs the control group (39 participants [0.19%]; P = .02). A significant difference in the combined detection rate of dysplasia and early gastric cancer was found between those in the intervention group (57 participants [0.27%]) vs the control group (35 participants [0.17%]; P = .02). For small gastric lesions (<1 cm), those who received cimetropium bromide had higher detection rates (24 participants [0.12%]) than those who did not (11 participants [0.05%]; P = .03). Lesions in the gastric body were detected significantly more often in the intervention group (34 participants [0.16%]) vs the control group (15 participants [0.07%]; P = .007). In multivariate analyses involving all 67 683 participants, the use of cimetropium bromide was more likely to detect gastric neoplasms compared with nonuse (odds ratio, 1.42; 95% CI, 1.04-1.95; P = .03).

CONCLUSIONS AND RELEVANCE

In this study, the use of cimetropium bromide as premedication was significantly associated with increased gastric neoplasm detection rates during EGD screening, and lesions in the gastric body were detected more frequently among those who received cimetropium bromide compared with those who did not. These findings suggest that cimetropium bromide may be considered as premedication before EGD examination among individuals with no contraindications.

Pharmacokinetics of florfenicol in blunt-snout bream (Megalobrama amblycephala) at two water temperatures with single-dose oral administration

The pharmacokinetics and residue elimination of florfenicol (FFC) and its metabolite florfenicol amine (FFA) were studied in healthy blunt-snout bream (Megalobrama amblycephala, 50 ± 10 g). The study was conducted with a single-dose (25 mg/kg) oral administration at a water temperature of 18 or 28°C, while in the residue elimination study, fish were administered at 25 mg/kg daily for three consecutive days by oral gavage to determine the withdrawal period (WDT) at 28°C. The FFC and FFA levels in plasma and tissues (liver, kidneys and muscle) were analysed using high-performance liquid chromatography (HPLC). A no-compartment model was used to analyse the concentration versus time data of M. amblycephala. In the two groups at 18 and 28°C, the maximum plasma concentration (C_max ) of FFC was 5.89 and 6.21 μg/ml, while the time to reach C_max (T_max ) was 5.97 and 2.84 hr, respectively. These suggested that higher temperature absorbed more drug and more quickly at M. amblycephala. And the elimination half-life (T_{1/2 kβ} ) of FFC was calculated as 26.75 and 16.14 hr, while the total body clearance (CL) was 0.09 and 0.15 L kg^-1  hr^-1 , and the areas under the concentration-time curves (AUCs) were 265.87 and 163.31 μg hr/ml, respectively. The difference demonstrated that the elimination rate of FFC in M. amblycephala at 28°C was more quickly than that at 18°C. The results of FFA showed the same trend in tissues of M. amblycephala. After multiple oral doses (25 mg/kg daily for 3 days), the k (eliminate rate constant) of FFA in M. amblycephala muscle was 0.017, the C₀ (initial concentration) was 3.07 mg/kg, and the WDT was 10 days (water temperature 28°C).

Choi C, Kim SJ, Nam HS, Ryu DG, Hong JB, Kim DJ. Cimetropium bromide does not improve polyp and adenoma detection during colonoscope withdrawal: A randomized, double-blind, placebo-controlled study

BACKGROUND

Endoscopic inspection of colonic mucosa is disturbed by colonic folds and peristalsis, which may result in missed polyps. Cimetropium bromide, an antispasmodic agent, inhibits peristalsis and colonic spasms, which may improve polyp detection. The purpose of this randomized, double-blind, placebo-controlled study was to investigate whether cimetropium bromide could improve polyp and adenoma detection in the colorectum and right colon.

METHODS

Patients undergoing screening or diagnostic colonoscopy were randomized to receive intravenous cimetropium bromide (5 mg) or placebo after cecal intubation. The primary outcomes were the number of polyps per patient (PPP) and adenomas per patient (APP); secondary outcomes were the polyp detection rate (PDR), adenoma detection rate (ADR), and advanced neoplasm detection rate (ANDR).

RESULTS

A total of 181 patients were analyzed; 91 patients received cimetropium bromide and 90 patients received placebo. Cimetropium bromide and placebo groups did not significantly differ in the PPP and APP for the colorectum (1.38 ± 1.58 vs 1.69 ± 2.28, P = .298; 0.96 ± 1.27 vs 1.11 ± 1.89, P = .517, respectively) and right colon (0.70 ± 0.95 vs 0.78 ± 1.21, P = .645; 0.47 ± 0.81 vs 0.51 ± 0.81, P = .757, respectively). Two groups also did not significantly differ in the PDR, ADR, and ANDR for the colorectum and right colon. Furthermore, there were no difference between groups in the PPP, APP, PDR, ADR, and ADNR in a sub-analysis of expert and non-expert endoscopists.

CONCLUSIONS

Cimetropium bromide did not improve polyp and adenoma detection in the colorectum and right colon during colonoscope withdrawal, regardless of the expertness of the endoscopist. However, its use may be helpful in patients with active peristalsis or for beginning endoscopists during standard colonoscopy without a transparent cap.

Pain-relieving agents for infantile colic

BACKGROUND

Infantile colic is a common disorder in the first months of life, affecting somewhere between 4% and 28% of infants worldwide, depending on geography and definitions used. Although it is self limiting and resolves by four months of age, colic is perceived by parents as a problem that requires action. Pain-relieving agents, such as drugs, sugars and herbal remedies, have been suggested as interventions to reduce crying episodes and severity of symptoms.

OBJECTIVES

To assess the effectiveness and safety of pain-relieving agents for reducing colic in infants younger than four months of age.

SEARCH METHODS

We searched the following databases in March 2015 and again in May 2016: CENTRAL, Ovid MEDLINE, Embase and PsycINFO, along with 11 other databases. We also searched two trial registers, four thesis repositories and the reference lists of relevant studies to identify unpublished and ongoing studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs evaluating the effects of pain-relieving agents given to infants with colic.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures of The Cochrane Collaboration.

MAIN RESULTS

We included 18 RCTs involving 1014 infants. All studies were small and at high risk of bias, often presenting major shortcomings across multiple design factors (e.g. selection, performance, attrition, lack of washout period).Three studies compared simethicone with placebo, and one with Mentha piperita; four studies compared herbal agents with placebo; two compared sucrose or glucose with placebo; five compared dicyclomine with placebo; and two compared cimetropium - one against placebo and the other at two different dosages. One multiple-arm study compared sucrose and herbal tea versus no treatment. Simethicone. Comparison with placebo revealed no difference in daily hours of crying reported for simethicone at the end of treatment in one small, low-quality study involving 27 infants. A meta-analysis of data from two cross-over studies comparing simethicone with placebo showed no difference in the number of of infants who responded positively to treatment (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.73 to 1.23; 110 infants, low-quality evidence).One small study (30 participants) compared simethicone with Mentha piperita and found no difference in crying duration, number of crying episodes or number of responders. Herbal agents. We found low-quality evidence suggesting that herbal agents reduce the duration of crying compared with placebo (mean difference (MD) 1.33, 95% CI 0.71 to 1.96; three studies, 279 infants), with different magnitude of benefit noted across studies (I² = 96%). We found moderate-quality evidence indicating that herbal agents increase response over placebo (RR 2.05, 95% CI 1.56 to 2.70; three studies, 277 infants). Sucrose. One very low-quality study involving 35 infants reported that sucrose reduced hours spent crying compared with placebo (MD 1.72, 95% CI 1.38 to 2.06). Dicyclomine. We could consider only one of the five studies of dicyclomine (48 infants) for the primary comparison. In this study, more of the infants given dicyclomine responded than than those given placebo (RR 2.50, 95% CI 1.17 to 5.34). Cimetropium bromide. Data from one very low-quality study comparing cimetropium bromide with placebo showed reduced crying duration among infants treated with cimetropium bromide (MD -30.20 minutes per crisis, 95% CI -39.51 to -20.89; 86 infants). The same study reported that cimetropium increased the number of responders (RR 2.29, 95% CI 1.44 to 3.64).No serious adverse events were reported for all of the agents considered, with the exception of dicyclomine, for which two of five studies reported relevant adverse effects (longer sleep 4%, wide-eyed state 4%, drowsiness 13%).

AUTHORS' CONCLUSIONS

At the present time, evidence of the effectiveness of pain-relieving agents for the treatment of infantile colic is sparse and prone to bias. The few available studies included small sample sizes, and most had serious limitations. Benefits, when reported, were inconsistent.We found no evidence to support the use of simethicone as a pain-relieving agent for infantile colic.Available evidence shows that herbal agents, sugar, dicyclomine and cimetropium bromide cannot be recommended for infants with colic.Investigators must conduct RCTs using standardised measures that allow comparisons among pain-relieving agents and pooling of results across studies. Parents, who most often provide the intervention and assess the outcome, should always be blinded.

Effect of concurrently coadministered drugs on the pharmacokinetic/pharmacodynamic profile of centchroman, a nonsteroidal oral contraceptive, in rats

INTRODUCTION

Centchroman (international nonproprietary name: ormeloxifene) is a nonsteroidal selective estrogen receptor modulator, oral contraceptive, anticancer and antiosteoporotic agent that is intended for long-term use by women. In view of the vast clinical applications and interactions of steroidal oral contraceptives with commonly used therapeutic agents, the interaction potential of certain concomitantly administered therapeutic agents was investigated in terms of postcoital contraceptive efficacy (pharmacological) and the pharmacokinetic profile of centchroman in female Sprague-Dawley rats. The coadministered drugs used in the study were ciprofloxacin, cefixime, amoxicillin, metronidazole, amlodipine, atenolol, theophylline, metformin, pioglitazone and glibenclamide.

MATERIALS AND METHODS

The pharmacological activity of centchroman was evaluated in sperm-positive female rats at 1.5 mg/kg, with or without coadministered drugs. Rats were sacrificed on Day 10 postcoitus, and autopsy was performed to check for the presence or absence of implantations. The estrogenic and antiestrogenic activities of centchroman were evaluated in immature ovariectomized rats. Pharmacokinetic interaction was studied in normal female rats with or without coadministered drugs. Serum samples were taken over 120 h and analyzed using a validated high-performance liquid chromatography method to generate the pharmacokinetic profile of centchroman. Pharmacokinetic parameters were estimated using noncompartmental analysis, and the results were compared.

RESULTS

In pharmacological interaction studies, centchroman alone showed a 100% success rate when given alone or in the presence of coadministered drugs. The only exception was amoxicillin coadministration, with 66% rats in the group showing resorbed implantations. Further investigation with amoxicillin in ovariectomized immature rats indicates no alteration in the estrogenic and antiestrogenic profiles of centchroman. In pharmacokinetic interaction studies, most of the therapeutic agents affected the rate and extent of absorption of centchroman. In other pharmacokinetic parameters, clearance (CL) remained unchanged; however, there was decrease in bioavailability (F) and volume of distribution (V(d)) in some situations.

CONCLUSIONS

The results indicate that there is no direct link between the altered pharmacokinetics of centchroman and the failure of pharmacological effect. The pharmacological interaction with amoxicillin could not be explained on the basis of alteration in the estrogenic and antiestrogenic activities of centchroman, indicating that different mechanisms are involved. The findings, however, suggest that amoxicillin coadministration may result in pharmacological interaction with centchroman and that caution should be taken in clinical practice.

A rapid and sensitive liquid chromatography/positive ion tandem mass spectrometry method for the determination of cimetropium in human plasma by liquid-liquid extraction

We have developed and validated a simple detection system with high-performance liquid chromatography (HPLC) with positive ion electrospray ionization tandem mass spectrometry (ESI-MS/MS) for determining cimetropium levels in human plasma using scopolamine butyl bromide as an internal standard (I.S.). The acquisition was performed in the multiple reaction monitoring (MRM) mode, by monitoring the transitions: m/z 357.9 > 103.1 for cimetropium and m/z 359.9 > 103.1 for butyl-scopolamine. The method involves a simple single-step liquid-liquid extraction with dichloromethane. The analyte was chromatographed on an YMC C18 reversed-phase chromatographic column by isocratic elution with 10 mM ammonium formate buffer-methanol (19:81, v/v; adjusted to pH 4.0 with formic acid). The results were linear over the studied range (0.2-100 ng ml(-1)), with r2 = 1.0000, and the total analysis time for each run was 2 min. Intra- and interassay precisions were 0.70-8.54% and 1.08-4.85%, respectively, and intra- and interassay accuracies were 97.56-108.23% and 97.48-103.91%, respectively. The lower limit of quantification (LLOQ) was 0.2 ng ml(-1). At this concentration, mean intra- and interassay precisions were 8.54% and 4.85%, respectively, and mean intra- and interassay accuracies were 97.56% and 98.91%, respectively. The mean recovery ranged from 62.71 +/- 4.06 to 64.23 +/- 2.32%. Cimetropium was found to be stable in plasma samples under typical storage and processing conditions. The devised assay was successfully applied to a pharmacokinetic study of cimetropium bromide administered as a single oral dose (150 mg) to healthy volunteers.

Evaluation of interaction potential of certain concurrently administered drugs with pharmacological and pharmacokinetic profile of centchroman in rats

Centchroman (Ormeloxifene) is a nonsteroidal, selective estrogen receptor modulator, oral contraceptive and anticancer agent, and is intended for long-term use by women. In view of its vast clinical application and the interaction of steroidal oral contraceptives with certain commonly used therapeutic agents, evaluation of interaction of certain concomitantly administered therapeutic agents (ibuprofen, rifampicin, diazepam, salbutamol, nifedipine, paracetamol, haloperidol, and tetracycline), in terms of both the postcoital contraceptive efficacy and pharmacokinetic profile, with centchroman was undertaken in female Sprague-Dawley rats. Among the representatives from each commonly used therapeutic category, interaction (pharmacokinetic) was observed with ibuprofen (60 mg/kg, twice daily), haloperidol (0.7 mg/kg, twice daily), and tetracycline (140 mg/kg, twice daily) coadministration on Days 1 through 5 postcoitum. Of these three therapeutic agents, only tetracycline interfered with the contraceptive efficacy of centchroman. It reduced the bioavailability of centchroman and its active metabolite by increasing their excretion through bile and feces. Increased metabolite excretion on tetracycline coadministration indicates the enterohepatic recirculation of the metabolite, not the parent drug. However, the effect of tetracycline was negated by the inclusion of lactic acid bacillus spores in the regimen.

Cimetropium bromide in the treatment of crisis in infantile colic

BACKGROUND

Treatment of infantile colic remains an open issue. In Italy, cimetropium bromide is used extensively to treat infantile colic. The aim of this randomized, double-blind, placebo-controlled clinical trial was to investigate the effectiveness and side effects of cimetropium bromide in the treatment of infants with colic crisis.

METHODS

Ninety-seven infants with colic were enrolled. The diagnosis of infantile colic in healthy infants with regular growth, aged 15 to 60 days was made according to the criteria of Wessel. The infants were divided into two groups, one treated with cimetropium bromide (1.2 mg/kg) and the other treated with placebo at onset of each crisis for 3 days. Duration of crying and side effects were recorded daily in a structured diary for the 3 days of therapy. Statistical analysis was performed using the chi-square and t tests.

RESULTS

Eighty-six infants completed the trial. The average duration of crying for each crisis was 17.3 +/- 12.6 minutes in the cimetropium bromide group and 47.5 +/- 28.5 minutes in the placebo group (P < 0.005). Response to cimetropium bromide was 74%. Response to placebo was 33% (P < 0.05). Side effects did not differ significantly between the two groups, except sleepiness, which increased in the infants treated with cimetropium bromide.

CONCLUSION

Cimetropium bromide was more effective than placebo in reducing the duration of crying in children with infantile colic. The use of the anticholinergic drugs, aside from the dicyclomine because of its dangerous side effects, should be revaluated for treating infantile colic.

Gastrointestinal transit and distribution of ranitidine in the rat

PURPOSE

Ranitidine gastrointestinal distribution was examined in the rat small intestine after oral administration to determine whether intestinal transit or secretion (exsorption) may influence the appearance of secondary peaks in ranitidine serum concentration-time profiles.

METHODS

Male Sprague-Dawley rats received ranitidine (50 mg/kg) by oral gavage, and the mass of ranitidine recovered in all small intestinal segments (approximately 12 cm each) was determined 30, 60, 90, or 120 min after administration. In a separate group of anesthetized rats, the small intestine was divided into two segments of equal length that were perfused with normal saline in a single-pass manner. Rats received an escalating, zero-order IV infusion of ranitidine for 30 min, and venous blood and intestinal effluent were collected over 90 min to quantitate ranitidine exsorption.

RESULTS

Thirty min after oral administration, > 50% of the recovered ranitidine mass resided in the lower half of the small intestine in all rats. Ranitidine mass in 5 of 16 rats displayed a bimodal distribution with significant amounts of ranitidine recovered from the stomach 60 to 90 min after dosing. Ranitidine exsorption was more efficient from the lower jejunum and ileum than from the duodenum and upper jejunum. However, intestinal secretion of ranitidine was minor (5% of the IV dose).

CONCLUSIONS

Ranitidine absorption from the lower ileum contributes significantly to systemic ranitidine concentrations before and during the time of the first concentration maximum. Separation of the drug mass into multiple boluses may contribute to secondary peaks in ranitidine concentration-time profiles. Exsorption did not contribute significantly to ranitidine distribution in the gastrointestinal tract.

Regional gastrointestinal absorption of ranitidine in the rat

PURPOSE

Ranitidine absorption from isolated segments of rat small intestine (duodenum, midgut, and terminal ileum) was investigated to examine the influence of pH and 50% bile, and to determine if ranitidine is absorbed preferentially from a specific region.

METHODS

Ranitidine (50 mg/kg) was administered into each segment in pH 5 or pH 7 buffer, or in 50% bile. Venous blood was collected at various times for 40 min from the right jugular vein.

RESULTS

When ranitidine was administered in pH 7 buffer or in 50% bile, Cmax and AUC0-40 were significantly greater after administration into the terminal ileum compared to the duodenum and midgut. AUC0-40 was significantly greater when ranitidine was administered in pH 5 buffer or in 50% bile into the duodenum compared to the midgut. Cmax was significantly different between administration into the duodenum and midgut only when ranitidine was administered in 50% bile. Ranitidine administration in pH 5 buffer significantly decreased AUC0-40 and Cmax after administration into the midgut, and AUC0-40 after administration into the terminal ileum compared to administration with pH 7 buffer or in 50% bile. Bile had no significant effect on AUC0-40 after ranitidine administration into the duodenum and midgut compared to administration in pH 7 buffer. However, bile significantly increased AUC0-40 and Cmax after ranitidine administration into the terminal ileum compared to administration with pH 7 and pH 5 buffer.

CONCLUSIONS

Results suggest that ranitidine is absorbed from the entire small intestine. However, the terminal ileum is the optimal site of gastrointestinal absorption. Furthermore, bile enhances ranitidine absorption from the terminal ileum.

Effect of cimetropium bromide on esophageal motility and transit in patients affected by primary achalasia

The effect of cimetropium bromide, a new anticholinergic agent, in patients with primary achalasia was studied. Twenty such patients (12 females and 8 males, mean age 38 years, range 15-56) were studied. Diagnosis was performed by radiology, endoscopy, and manometry. Lower esophageal sphincter pressure and body wave amplitude were measured by means of a five-channel catheter constantly perfused by a low-compliance pneumohydraulic pump. Patient received cimetropium bromide 10 mg intravenously over 3 min or placebo in a double-blind manner. In five patients esophageal transit evaluated by scintiscanning was studied on separate occasions after cimetropium bromide or placebo. Baseline mean lower esophageal sphincter pressure was 46 +/- 5 mm Hg and mean amplitude of body waves was 30 +/- 8 mm Hg. Cimetropium bromide induced a significant decrease in sphincter pressure and body wave amplitude that measured 13 +/- 3 mm Hg and 8 +/- 4 mm Hg, respectively, 15 min after the end of infusion. The decrease was maintained for 45 +/- 5 min. A marked reduction in repetitive body waves was also noted. Esophageal transit was also accelerated with cimetropium bromide. Maximal stomach radioactivity was observed after 8 +/- 1.8 sec while with placebo this was reached after 65 +/- 1.5 sec (P < 0.01). It is concluded with cimetropium bromide reduces LES pressure and shortens transit in primary esophageal achalasia. It may be useful in the treatment of this esophageal motility disorder.

Pharmacokinetics and bioinversion of ibuprofen enantiomers in humans

An open, randomized, six-way crossover study was conducted in 12 healthy males to assess pharmacokinetics and bioinversion of ibuprofen enantiomers. The mean plasma terminal half-life (t1/2) of R(-)ibuprofen was 1.74 hr when intravenously infused as a racemic mixture and was 1.84 hr when intravenously infused alone. The mean t1/2 of S(+)ibuprofen was 1.77 hr when dosed as S(+)ibuprofen. Examination of values of both the absorption and disposition parameters of R(-)ibuprofen revealed that the kinetics of R(-)ibuprofen were not altered by concurrent administration of S(+)ibuprofen. In this study, there was little or no presystemic inversion of R(-)ibuprofen to its S(+)isomer. Also, 69% of the intravenous dose of R(-)ibuprofen was systemically inverted and 57.6% of the oral dose of R(-)ibuprofen lysinate was bioavailable as S(+)ibuprofen. These results indicate that the bioinversion of R(-)ibuprofen administered orally is mainly systemic. Because bioinversion of R(-)ibuprofen is not complete, S(+)ibuprofen produced higher bioavailability of S(+)ibuprofen (92.0%) than either racemic ibuprofen (70.7%) or R(-)ibuprofen (57.6%). However, bioavailability of R(-)ibuprofen (83.6%) when dosed alone was not significantly different from when dosed as racemic mixture (80.7%).

Use of a pharmacokinetic model incorporating discontinuous gastrointestinal absorption to examine the occurrence of double peaks in oral concentration-time profiles

Double peaks in the plasma concentration-time profile following oral administration have been reported for several compounds. A pharmacokinetic model incorporating discontinuous absorption was developed to simulate concentration-time profiles with double peaks. The gastrointestinal (GI) tract was divided into N compartments, with absorption occurring only from the second and Nth compartments. A two-compartment model was used to describe systemic drug disposition. The effect of gastric emptying and GI transit rate constants (Kl and K1, respectively), number of hypothetical gut compartments, and absorption rate constant at each site (Ka1, Ka2) on the time of occurrence of each peak (Tp1, Tp2), the theoretical fraction of the dose absorbed at each site (phi 1, phi 2), and the contribution of the second site to systemic drug exposure (expressed as phi 2rel) were examined. Simulated concentration-time profiles demonstrated that Tp2 was determined by Kt and N, while Tp1 was determined by K1 and Kt. Changes in Ka1 and Ka2 had no effect on Tp1 or Tp2. phi 1, phi 2, and phi 2rel were determined by Ka1, Ka2, and Kt, and simulations indicated that a secondary peak in the concentration-time profile will be evident only when phi 2rel is substantial. In addition, concentration-time data for ranitidine and cimetidine, which displayed double peaks, were fit with the model. The present model described both data sets well, and realistic pharmacokinetic and physiologic parameters (absorption rate constants, systemic bioavailabilities, GI residence times) were obtained.

Longterm treatment of irritable bowel syndrome with cimetropium bromide: a double blind placebo controlled clinical trial

The aim of this study was to evaluate the efficacy of cimetropium bromide, a new antimuscarinic compound, in relieving symptoms of patients with irritable bowel syndrome over a three month period. Seventy consecutive outpatients were given cimetropium (50 mg tid) or placebo according to a double blind, randomised, parallel groups design. Symptoms were evaluated initially and at monthly intervals up to the end of the study period. One patient receiving placebo withdrew because of treatment failure. Pain score decreased by 40, 66, 85% in the cimetropium group, at the end of the first, second and third months respectively, compared with 26, 32 and 52% reductions among controls (p = 0.0005). At the end of treatment there was a 86% reduction in the number of abdominal pain episodes per day in the cimetropium group compared with 50% in the placebo group (p = 0.001). Constipation and diarrhoea scores decreased by 59 and 49% in the cimetropium treated patients, compared with 37 and 39% in controls, the differences between being not significant. At the end of the study 89% of the patients treated with cimetropium considered themselves as globally improved as opposed to 69% in the placebo group (p = 0.039). The corresponding 95% confidence intervals for the differences between the proportion of improved patients in the two groups were from 11% to 29%. Six patients taking cimetropium complained of slight dry mouth. The results of this study showed that cimetropium bromide is effective in relieving pain in patients with irritable bowel syndrome.

Effects of cimetropium bromide on gastrointestinal transit time in patients with irritable bowel syndrome

Cimetropium bromide is a new antimuscarinic compound with strong antispasmodic activity. The aim of this study was to evaluate the effects of oral cimetropium bromide on total gut transit time in patients with irritable bowel syndrome. Forty patients, divided according to their initial total gastrointestinal transit times and presenting symptoms, were treated with cimetropium bromide 50 mg t.d.s. or placebo for 1 month according to a double-blind, parallel group design. Before and after treatment all subjects ingested 24 radio-opaque markers. The total intestinal transit time was determined by evaluating the rate of disappearance of markers from plain X-ray films of the abdomen taken every 24 h for 4 days. Pain and bowel habits were also monitored. Seven patients did not complete the study. Cimetropium bromide significantly (P less than 0.01) shortened the whole gut transit time in patients with prolonged transit time (80.8 +/- 4.0 h before vs 60.8 +/- 6.7 h after treatment) and improved the global clinical condition significantly compared with placebo (P = 0.029). In patients with a short total intestinal transit time, cimetropium bromide had no effect on whole gut transit time and did not significantly improve symptoms. The results of this study indicate that oral cimetropium bromide is effective both objectively and subjectively in a subgroup of irritable bowel syndrome patients with constipation.

Manometric evaluation of cimetropium bromide activity in patients with the nutcracker oesophagus

There are at present few therapeutic alternatives to calcium channel blockers for the medical treatment of patients with nutcracker oesophagus. For this reason, we evaluated by means of a low-compliance manometric system the effect of a new anticholinergic compound, cimetropium bromide (10 mg intravenously), on oesophageal variables of eight patients with nutcracker oesophagus, in a single-blind study. Eight age-matched healthy volunteers served as controls. In both patients and controls, cimetropium bromide significantly decreased lower oesophageal sphincter pressure and the distal and proximal mean contraction amplitude of the oesophageal body. Apart from an increase in pulse rate, no noteworthy side effects were observed. It is concluded that cimetropium bromide may be an effective therapeutic option in patients with nutcracker oesophagus.

Reduction by cimetropium bromide of the colonic motor response to eating in patients with the irritable bowel syndrome

Cimetropium bromide is an antimuscarinic compound with antispasmodic properties. Its effect on meal-stimulated sigmoid motor activity in 30 patients with the irritable bowel syndrome, mainly with pain and constipation, has been evaluated. The mechanical activity of the sigmoid colon was recorded with a probe with three open-tipped tubes ending 45, 30, and 15 cm from the anal margin. After a recording period of 60 min, 5 mg cimetropium bromide or saline was given i.v., according to a randomized, double-blind design 5 min before a 1000 calorie meal, and motility was then recorded for 2 h. The meal caused a significant increase in motor activity for 90 min in the saline-treated group. Cimetropium bromide abolished the peak of motor activity 10-20 min after the meal and significantly inhibited postprandial colonic motility for at least 2 h (p less than 0.01). This effect provides a rationale for the use of cimetropium bromide in treatment of the irritable bowel syndrome.