Dog and human bladders have different neurogenic and nicotinic responses in inner versus outer detrusor muscle layers.

The aim of this study was to investigate layer and species variations in detrusor muscle strip responses to myogenic, neurogenic, and nicotinic, and muscarinic receptor stimulations. Strips from bladders of 9 dogs and 6 human organ transplant donors were dissected from inner and outer longitudinal muscle layers, at least 1 cm above urethral orifices. Strips were mounted in muscle baths and maximal responses to neurogenic stimulation using electrical field stimulation (EFS) and myogenic stimulation using potassium chloride (KCl, 120 mM) determined. After washing and re-equilibration was completed, responses to nicotinic receptor agonist epibatidine (10 µM) were determined followed by responses to EFS and muscarinic receptor agonist bethanechol (30 µM) in continued presence of epibatidine. Thereafter, strips and full-thickness bladder sections from four additional dogs and three human donors were examined for axonal density and intramural ganglia. In dog bladders, contractions to KCl, epibatidine, and bethanechol were 1.5- to 2-fold higher in the inner longitudinal muscle layer, whereas contractions to EFS were 1.5-fold higher in the outer (both pre- and post-epibatidine). Human bladders showed 1.2-fold greater contractions to epibatidine in the inner layer and to EFS in the outer, yet no layer differences to KCl or bethanechol were noted. In both species, axonal density was 2- to 2.5-fold greater in the outer layer. Dogs had more intramural ganglia in the adventitia/serosa layer, compared with more internal layers and to humans. These findings indicate several layer-dependent differences in receptor expression or distribution, and neurogenic responses in dog and human detrusor muscles, and myogenic/muscarinic differences between dog versus humans.

Postoperative interventions for preventing bladder dysfunction after radical hysterectomy in women with early-stage cervical cancer.

BACKGROUND: Bladder dysfunction is a common complication following radical hysterectomy, caused by the damage to pelvic autonomic nerves that innervate the muscles of the bladder, urethral sphincter, and pelvic floor fasciae. Bladder dysfunction increases the rates of urinary tract infection, hospital visits or admission, and patient dissatisfaction. In addition, bladder dysfunction can also negatively impact patient quality of life (QoL). Several postoperative interventions have been proposed to prevent bladder dysfunction following radical hysterectomy. To our knowledge, there has been no systematic review evaluating the effectiveness and safety of these interventions for preventing bladder dysfunction following radical hysterectomy in women with cervical cancer. OBJECTIVES: To evaluate the effectiveness and safety of postoperative interventions for preventing bladder dysfunction following radical hysterectomy in women with early-stage cervical cancer (stage IA2 to IIA2). SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 4) in the Cochrane Library, MEDLINE via Ovid (1946 to April week 2, 2020), and Embase via Ovid (1980 to 2020, week 16). We also checked registers of clinical trials, grey literature, conference reports, and citation lists of included studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) evaluating the effectiveness and safety of any type of postoperative interventions for preventing bladder dysfunction following a radical hysterectomy in women with stage IA2 to IIA2 cervical cancer. DATA COLLECTION AND ANALYSIS: Two review authors independently selected potentially relevant RCTs, extracted data, assessed risk of bias, compared results, and made judgments on the quality and certainty of the evidence. We resolved any disagreements through discussion or consultation with a third review author. Outcomes of interest consisted of spontaneous voiding recovery one week after the operation, quality of life (QoL), adverse events, post-void residual urine volume one month after the operation, urinary tract infection over the one month following the operation, and subjective urinary symptoms. MAIN RESULTS: We identified 1464 records as a result of the search (excluding duplicates). Of the 20 records that potentially met the review criteria, we included five reports of four studies. Most of the studies had unclear risks of selection and reporting biases. Of the four studies, one compared bethanechol versus placebo and three studies compared suprapubic catheterisation with intermittent self-catheterisation. We identified two ongoing studies. Bethanechol versus placebo The study reported no information on the rate of spontaneous voiding recovery at one week following the operation, QoL, adverse events, urinary tract infection in the first month after surgery, and subjective urinary symptoms for this comparison. The volume of post-void residual urine, assessed at one month after surgery, among women receiving bethanechol was lower than those in the placebo group (mean difference (MD) -37.4 mL, 95% confidence interval (CI) -60.35 to -14.45; one study, 39 participants; very-low certainty evidence). Suprapubic catheterisation versus intermittent self-catheterisation The studies reported no information on the rate of spontaneous voiding recovery at one week and post-void residual urine volume at one month following the operation for this comparison. There was no difference in risks of acute complication (risk ratio (RR) 0.77, 95% CI 0.24 to 2.49; one study, 71 participants; very low certainty evidence) and urinary tract infections during the first month after surgery (RR 0.77, 95% CI 0.53 to 1.13; two studies, 95 participants; very- low certainty evidence) between participants who underwent suprapubic catheterisation and those who underwent intermittent self-catheterisation. Available data were insufficient to calculate the relative measures of the effect of interventions on QoL and subjective urinary symptoms. AUTHORS' CONCLUSIONS: None of the included studies reported rate of spontaneous voiding recovery one week after surgery, time to a post-void residual volume of urine of 50 mL or less, or post-void residual urine volume at 6 and 12 months after surgery, all of which are important outcomes for assessing postoperative bladder dysfunction. Limited evidence suggested that bethanechol may minimise the risk of bladder dysfunction after radical hysterectomy by lowering post-void residual urine volume. The certainty of this evidence, however, was very low. The effectiveness of different types of postoperative urinary catheterisation (suprapubic and intermittent self-catheterisation) remain unproven.

Airway cholinergic history modifies mucus secretion properties to subsequent cholinergic challenge in diminished chloride and bicarbonate conditions.

NEW FINDINGS: What is the central question of this study? What is the impact of airway cholinergic history on the properties of airway mucus secretion in a cystic fibrosis-like environment? What is the main finding and its importance? Prior cholinergic challenge slightly modifies the characteristics of mucus secretion in response to a second cholinergic challenge in a diminished bicarbonate and chloride transport environment. Such modifications might lead to retention of mucus on the airway surface, thereby potentiating exacerbations of airway disease. ABSTRACT: Viral infections precipitate exacerbations in many airway diseases, including asthma and cystic fibrosis. Although viral infections increase cholinergic transmission, few studies have examined how cholinergic history modifies subsequent cholinergic responses in the airway. In our previous work, we found that airway resistance in response to a second cholinergic challenge was increased in young pigs with a history of airway cholinergic stimulation. Given that mucus secretion is regulated by the cholinergic nervous system and that abnormal airway mucus contributes to exacerbations of airway disease, we hypothesized that prior cholinergic challenge would also modify subsequent mucus responses to a secondary cholinergic challenge. Using our established cholinergic challenge-rechallenge model in pigs, we atomized the cholinergic agonist bethanechol or saline control to pig airways. Forty-eight hours later, we removed tracheas and measured mucus secretion properties in response to a second cholinergic stimulation. The second cholinergic stimulation was conducted in conditions of diminished chloride and bicarbonate transport to mimic a cystic fibrosis-like environment. In pigs previously challenged with bethanechol, a second cholinergic stimulation produced a mild increase in sheet-like mucus films; these films were scarcely observed in animals originally challenged with saline control. The subtle increase in mucus films was not associated with changes in mucociliary transport. These data suggest that prior cholinergic history might modify mucus secretion characteristics with subsequent stimulation in certain environmental conditions or disease states. Such modifications and/or more repetitive stimulation might lead to retention of mucus on the airway surface, thereby potentiating exacerbations of airway disease.

Bethanechol: Is it still being prescribed for bladder dysfunction in women?

PURPOSE: Few medical treatment options exist for detrusor underactivity or urinary retention in women. Bethanechol, a cholinergic agonist, may improve detrusor contractility in these conditions; however, its clinical efficacy is limited. We sought to examine the patterns of Bethanechol use by physicians in an ambulatory care setting using a national database to determine if it is still prescribed for patients with bladder dysfunction. MATERIALS AND METHODS: The National Ambulatory Medical Care Survey (NAMCS) database was queried for a sample of patient visits to office-based physicians from 2003-2013. Visits were included for women aged 18 years or older with diagnosed lower urinary tract symptoms (LUTS), neurogenic bladder, or urinary retention based on ICD-9-CM codes. Visits in which Bethanechol was prescribed were analysed with descriptive statistics. Sampling weights were adjusted for nonresponders to yield an unbiased national estimate of ambulatory care visits. RESULTS: Out of a weighted sample of 17 321 630 included patient visits, 132 281 (0.8%) visits included a prescription for Bethanechol. Patients prescribed Bethanechol had a mean age of 62.3 ± 2.1 and were predominantly Caucasian (67%) followed by African American (18%). The primary diagnosis associated with Bethanechol was atony of bladder (35%), urinary retention (20%), neurogenic bladder (18%), urinary incontinence (16%), and incomplete bladder emptying (10%). Visits were primarily for chronic conditions (63%). It was typically prescribed as a continued medication (79%) most often by urologists (92%) followed by internal medicine clinicians (8%). CONCLUSIONS: Bethanechol continues to be prescribed in elderly women primarily for detrusor atony, urinary retention, or incomplete bladder emptying.

Identification of Drug Candidates to Suppress Cigarette Smoke-induced Inflammation via Connectivity Map Analyses.

Cigarette smoking is the main risk factor for chronic obstructive pulmonary disease, and to date, existing pharmacologic interventions have been ineffective at controlling inflammatory processes associated with the disease. To address this issue, we used the Connectivity Map (cMap) database to identify drug candidates with the potential to attenuate cigarette smoke-induced inflammation. We queried cMap using three independent in-house cohorts of healthy nonsmokers and smokers. Potential drug candidates were validated against four publicly available human datasets, as well as six independent datasets from cigarette smoke-exposed mice. Overall, these analyses yielded two potential drug candidates: kaempferol and bethanechol. Subsequently, the efficacy of each drug was validated in vivo in a model of cigarette smoke-induced inflammation. BALB/c mice were exposed to room air or cigarette smoke and treated with each of the two candidate drugs either prophylactically or therapeutically. We found that kaempferol, but not bethanechol, was able to reduce cigarette smoke-induced neutrophilia, both when administered prophylactically and when administered therapeutically. Mechanistically, kaempferol decreased expression of IL-1α and CXCL5 concentrations in the lung. Our data suggest that cMap analyses may serve as a useful tool to identify novel drug candidates against cigarette smoke-induced inflammation.

New technology assessment and current and upcoming therapies for underactive bladder.

BACKGROUND AND AIMS: Stakeholders from around the world came together to address the unmet needs of underactive bladder (UAB) at the 3rd International Congress for Underactive Bladder. METHODS: The main recommendation from the regulatory working group is a need for a meeting of UAB stakeholders and regulatory agencies including the FDA to discuss guidance for regulatory trial design for devices, drugs, and/or biologics for UAB. RESULTS: The following issues to be discussed and agreed upon for UAB trials: 1) Appropriate inclusion and exclusion criteria. 2) Should residual urine volume be the primary outcome parameter and how often should it be measured? 3) Are there secondary measures that should have a place in UAB trials, such as change in the number of catheterizations, quality of life measures, etc.? 4) Use and format of bladder voiding and catheterization diary for trials. 5) Define role and technique of urodynamics in UAB trials. Are urodynamics required to monitor, and possibly exclude, individuals with high pressure voiding induced by bladder prokinetic therapies? 6) Development and use of UAB questionnaires. DISCUSSION AND CONCLUSION: The UAB regulatory working group recognizes the path forward should include engaging the FDA and other regulatory organizations that may harmonize and formalize guidance for regulatory trial designs for therapeutics for UAB.

Salt, sweat, and unclear? Diaphoresis and hypernatremia in end-stage kidney disease: Questions.

This quiz will discuss two patients with end-stage kidney disease (ESKD) on dialysis presenting with diaphoresis and hypernatremia.

Solitary Cholinergic Stimulation Induces Airway Hyperreactivity and Transcription of Distinct Pro-inflammatory Pathways.

Airway hyperreactivity is a hallmark feature of asthma and can be precipitated by airway insults, such as ozone exposure or viral infection. A proposed mechanism linking airway insults to airway hyperreactivity is augmented cholinergic transmission. In the current study, we tested the hypothesis that acute potentiation of cholinergic transmission is sufficient to induce airway hyperreactivity. We atomized the cholinergic agonist bethanechol to neonatal piglets and forty-eight hours later measured airway resistance. Bethanechol-treated piglets displayed increased airway resistance in response to intravenous methacholine compared to saline-treated controls. In the absence of an airway insult, we expected to find no evidence of airway inflammation; however, transcripts for several asthma-associated cytokines, including IL17A, IL1A, and IL8, were elevated in the tracheas of bethanechol-treated piglets. In the lungs, prior bethanechol treatment increased transcripts for IFNγ and its downstream target CXCL10. These findings suggest that augmented cholinergic transmission is sufficient to induce airway hyperreactivity, and raise the possibility that cholinergic-mediated regulation of pro-inflammatory pathways might contribute.

Salivary hypofunction: An update on therapeutic strategies.

OBJECTIVE: To perform a literature review addressing the therapeutic strategies for salivary hypofunction. BACKGROUND: Qualitative and quantitative salivary dysfunctions predispose to changes in the oral mucosa and teeth, cause impairment to oral functions and negative impact on quality of life. MATERIALS AND METHODS: A MEDLINE/PubMed search was conducted using the terms "Xerostomia" AND, "Saliva Artificial" OR, "Citric Acid," "Malic Acid," "Chewing Gum," "Acupuncture" OR, "Pilocarpine" OR, "Bethanechol" OR, "Cevimeline" OR, "Hyperbaric Oxygen Therapy" OR, "Stem Cell Therapy" OR "Genetic Therapy" and their Mesh Terms. RESULTS: We selected 25 clinical trials investigating the effects of salivary substitutes, chewing gum, malic and citric acids, pilocarpine, cevimeline, bethanechol, acupuncture, hyperbaric oxygen therapy and regenerative therapies on salivary hypofunction. In most studies, the number of participants was low and the follow-up times short. The therapeutic modalities were classified according to the level of evidence on salivary dysfunction. CONCLUSIONS: Pilocarpine and cevimeline had the strongest evidence of beneficial effect on salivary hypofunction. Citric and malic acids increase salivary flow but also increase the risk of erosion and dental caries. There are no controlled clinical trials supporting the efficacy of acupuncture, stem cell therapy and gene therapy on salivary dysfunction, although clinical observations suggest a promising effect. There is no evidence supporting salivary substitutes, chewing gum, bethanechol or hyperbaric oxygen on the treatment of salivary hypofunction.

Malakoplakia of the large intestine: an incidental extremely rare finding.

Malakoplakia is a rare inflammatory disease, most commonly found in the urinary tract. It appears be related to a functional deficiency of macrophages, resulting in an inability to destroy digested bacteria and it is associated with various conditions that cause immunodeficiency. A rare case of malakoplakia of the colon in a healthy 68-year old male is presented. The patient underwent emergency surgery with colon resection and an end stoma with closure of the distal bowel (Hartmann's procedure), due to incarcerated ventral hernia and sigmoid-colon rupture. He underwent reversal of the Hartmann's procedure four months after the initial operation. The histological examination from the anastomotic rings revealed Michaelis-Gutmann bodies that are pathognomonic of malakoplakia. He received per os ciprofloxacin, bethanecol and ascorbic acid for 12 months. Follow-up endoscopy did not exhibit any signs of the disease. A case of a healthy patient presenting with malakoplakia without any underlying disease that causes immunodeficiency is extremely rare. Treatment of malakoplakia involves the eradication of microorganisms. Cholinergic agonists, such as bethanechol and ascorbic acid, as well as antimicrobial treatment with trimpethoprim/sulphamethoxazol and rifampicin are most commonly being used. Long-term antimicrobial treatment has been reported (6 months to 3 years).

Influence of bethanechol on salivary parameters in irradiated patients.

BACKGROUND: Some studies have shown evidence that the prophylactic use of bethanechol chloride (BC) may be useful in preventing the incidence and/or severity of xerostomia (XT). However, the indication of BC in irradiated patients with XT needs to be better characterized. The study aimed to evaluate the influence of BC on XT, salivary flow rate, and salivary composition in patients previously submitted to head and neck radiotherapy. MATERIAL AND METHODS: Forty five irradiated patients complaining of XT used 50 mg/day of BC for 3 months, and the salivary parameters were evaluated in 4 Phases (Before BC therapy, after one month of BC, 2 months of BC, and 3 months of BC). Biochemical analysis included buffering capacity; pH; total protein concentration (TP); amylase concentration (AM); catalase (CAT) and peroxidase (PX) activities. In addition, unstimulated and stimulated salivary flow rates were determined and XT was classified. RESULTS: According to the XT grading system used, patients showed improvement in XT between Phase 1, and Phases 2, 3 and 4. In addition, some changes were observed in TP concentration (decreased); AM concentration (increased); and PX and CAT activities (decreased and increased, respectively) after Phase 2, for stimulated saliva collection (p<0.05). CONCLUSIONS: Our results suggested that when BC was used to treat salivary gland dysfunction induced by head and neck radiotherapy, improvement in XT symptoms, and some changes in saliva composition were shown.

Haustral boundary contractions in the proximal 3-taeniated rabbit colon.

The rabbit proximal colon is similar in structure to the human colon. Our objective was to study interactions of different rhythmic motor patterns focusing on haustral boundary contractions, which create the haustra, using spatiotemporal mapping of video recordings. Haustral boundary contractions were seen as highly rhythmic circumferential ring contractions that propagated slowly across the proximal colon, preferentially but not exclusively in the anal direction, at ∼0.5 cycles per minute; they were abolished by nerve conduction blockers. When multiple haustral boundary contractions propagated in the opposite direction, they annihilated each other upon encounter. Ripples, myogenic propagating ring contractions at ∼9 cycles per min, induced folding and unfolding of haustral muscle folds, creating an anarchic appearance of contractile activity, with different patterns in the three intertaenial regions. Two features of ripple activity were prominent: frequent changes in propagation direction and the occurrence of dislocations showing a frequency gradient with the highest intrinsic frequency in the distal colon. The haustral boundary contractions showed an on/off/on/off pattern at the ripple frequency, and the contraction amplitude at any point of the colon showed waxing and waning. The haustral boundary contractions are therefore shaped by interaction of two pacemaker activities hypothesized to occur through phase-amplitude coupling of pacemaker activities from interstitial cells of Cajal of the myenteric plexus and of the submuscular plexus. Video evidence shows the unique role haustral folds play in shaping contractile activity within the haustra. Muscarinic agents not only enhance the force of contraction, they can eliminate one and at the same time induce another neurally dependent motor pattern.

Neuropeptide S inhibits gastrointestinal motility and increases mucosal permeability through nitric oxide.

Neuropeptide S (NPS) receptor (NPSR1) polymorphisms are associated with enteral dysmotility and inflammatory bowel disease (IBD). This study investigated the role of NPS in conjunction with nitrergic mechanisms in the regulation of intestinal motility and mucosal permeability. In rats, small intestinal myoelectric activity and luminal pressure changes in small intestine and colon, along with duodenal permeability, were studied. In human intestine, NPS and NPSR1 were localized by immunostaining. Pre- and postprandial plasma NPS was measured by ELISA in healthy and active IBD humans. Effects and mechanisms of NPS were studied in human intestinal muscle strips. In rats, NPS 100-4,000 pmol·kg(-1)·min(-1) had effects on the small intestine and colon. Low doses of NPS increased myoelectric spiking (P < 0.05). Higher doses reduced spiking and prolonged the cycle length of the migrating myoelectric complex, reduced intraluminal pressures (P < 0.05-0.01), and increased permeability (P < 0.01) through NO-dependent mechanisms. In human intestine, NPS localized at myenteric nerve cell bodies and fibers. NPSR1 was confined to nerve cell bodies. Circulating NPS in humans was tenfold below the ∼0.3 nmol/l dissociation constant (Kd) of NPSR1, with no difference between healthy and IBD subjects. In human intestinal muscle strips precontracted by bethanechol, NPS 1-1,000 nmol/l induced NO-dependent muscle relaxation (P < 0.05) that was sensitive also to tetrodotoxin (P < 0.01). In conclusion, NPS inhibits motility and increases permeability in neurocrine fashion acting through NO in the myenteric plexus in rats and humans. Aberrant signaling and upregulation of NPSR1 could potentially exacerbate dysmotility and hyperpermeability by local mechanisms in gastrointestinal functional and inflammatory reactions.

Partial agonistic effects of pilocarpine on Ca(2+) responses and salivary secretion in the submandibular glands of live animals.

NEW FINDINGS: What is the central question of this study? Pilocarpine stimulates salivary secretion via muscarinic ACh receptors (mAChRs), although the Ca(2+) -mobilizing effect of pilocarpine in salivary gland cells is extremely small. Therefore, we examined the effect of pilocarpine on Ca(2+) responses in submandibular gland cells and on secretion in vitro and in vivo. What is the main finding and its importance? Pilocarpine induces small Ca(2+) responses and reduces the effects of other mAChR agonists on Ca(2+) responses via its partial agonistic effects. These effects of pilocarpine on Ca(2+) responses in the submandibular gland were further established in vivo with a novel Ca(2+) imaging system and a genetically encoded Ca(2+) indicator. Pilocarpine stimulates salivary secretion via muscarinic ACh receptors (mAChRs), although the effect of pilocarpine on Ca(2+) responses in dispersed salivary gland cells is extremely small. Here, we demonstrate the effect of pilocarpine on Ca(2+) responses and salivary secretion in the rat submandibular gland (SMG). In fura-2-loaded SMG cells, the maximal effect of pilocarpine on [Ca(2+) ]i elevation was 16% of that of carbachol, and pilocarpine attenuated carbachol- and bethanechol (Bet)-induced [Ca(2+) ]i increases, indicating that pilocarpine acts as a partial agonist for mAChR-mediated Ca(2+) responses. The partial agonistic effect of pilocarpine on Ca(2+) dynamics in the SMG was also confirmed in live animals using the genetically encoded Ca(2+) indicator, YC-Nano50. Administration of pilocarpine (3 mg kg(-1) , i.p.) elicited a small increase in [Ca(2+) ]i in the SMG. Quantitative analyses demonstrated that resting [Ca(2+) ]i was ∼37 nm, which was increased by pilocarpine (3 mg kg(-1) ) and Bet (10 mg kg(-1) ) to 44 and 69 nm, respectively. The inhibitory effects of pilocarpine on Bet-induced Ca(2+) responses were also elucidated in vivo. We further examined real-time changes in pilocarpine-induced SMG salivary secretion and showed that pilocarpine induced an extremely weak secretory response and reduced Bet-induced secretion. Unlike Ca(2+) responses, pilocarpine failed to reduce the effect of Bet on SMG blood flow. Our results demonstrate that pilocarpine acts as a partial agonist of mAChRs to induce weak salivary secretion that is correlated with small increases in [Ca(2+) ]i . Furthermore, pilocarpine exhibits an antagonistic effect on mAChR-induced Ca(2+) responses and salivary secretion.

Characterization of the motor inhibitory role of colonic mucosa under chemical stimulation in mice.

The main roles of the colonic mucosa are the absorption of water and electrolytes and the barrier function that preserves the integrity of the colonic wall. The mediators and mechanisms to accomplish these functions are under continuous investigation, but little attention has been paid to a possible control of colonic motility by the mucosa that would fine tune the relationship between absorption and motility. The purpose of this study was to establish the role of the mucosa in the control of induced colonic contractility. Young ICR-CD1 mice (3-5 mo old) were studied. Isometric tension transducers were used to record contractility in full-thickness (FT) and mucosa-free (MF) strips from proximal colon. Proximal FT strips showed lower KCl- and bethanechol-induced responses than MF strips. The difference was not due to mechanical artefacts since the contractile response of FT strips to electrical field stimulation was around 50% lower than in MF. The inhibitory effects of the mucosa on FT strips were mimicked by immersion of separate strips of mucosa in the organ bath but not by addition of mucosal extract, suggesting gaseous molecules as mediators of this effect. Incubation of MF strips with synthase inhibitors of nitric oxide, carbon monoxide, and hydrogen sulfide abolished the inhibition caused by addition of the mucosal strip, indicating that mucosal gasotransmitters are the mediators of these effects. This suggests that the control of colonic motility exerted by the mucosa could fine tune the balance between transit and absorption.

Effects of bethanechol chloride and distigmine bromide on postvoiding residual volume in patients with underactive bladder.

AIM: The efficacy of cholinergic drugs for reduction of post-voiding residual volume (PVR) in patients with underactive bladder is still controversial. This study was performed to examine whether cholinergic drugs have such an effect on PVR. METHODS: Patients with underactive bladder treated for more than two months with cholinergic drugs, which were later discontinued, were extracted retrospectively based on their charts. The changes in PVR, cholinesterase activity (ChE), renal function, and voiding function before and after discontinuation of cholinergic drugs were reviewed and analyzed. RESULTS: Twenty-nine patients were included in this study. In multiple linear regression analysis, the discontinuation of distigmine bromide (DB) was indicated as a significant covariate for PVR increase and ChE increase, while bethanechol chloride (BC) was not a significant covariate. The increase in ChE was significantly correlated with both PVR and voided volume after discontinuation of cholinergic drugs. CONCLUSION: DB could reduce PVR via a decrease in ChE. However, BC at doses up to 60 mg did not reduce PVR. DB may be recommended for the reduction of PVR in patients with underactive bladder.

Physicochemical and Microbiological Stability of Compounded Bethanechol Chloride Oral Suspensions in PCCA Base, SuspendIt®.

Bethanechol chloride is a cholinergic agent used to treat acute postoperative and postpartum nonobstructive (functional) urinary retention and for neurogenic atony of the urinary bladder with retention. It is available in the United States as tablets for oral administration in four dosage strengths: 5 mg, 10 mg, 25 mg, and 50 mg. A review of the therapeutic uses of bethanechol chloride reveals the need for flexibility in dosing. This flexibility is readily achieved using an oral liquid dosage form. However, no commercial liquid dosage form of bethanechol chloride currently exists. An extemporaneously compounded suspension from pure drug powder or commercial tablets would provide a flexible, customizable option to meet unique patient needs with convenient and accurate dosing options. The purpose of this study was to determine the physicochemical and microbiological stability of extemporaneously compounded bethanechol chloride suspensions using two brands of commercially available tablets (Amneal and Upsher-Smith) in the PCCA Base, SuspendIt. This base is a sugar-free, paraben-free, dye-free, and gluten-free thixotropic vehicle containing a natural sweetener obtained from the monk fruit. The study design included two bethanechol chloride concentrations to provide stability documentation over a bracketed concentration range for eventual use by compounding pharmacists. A robust stability-indicating ultra-high-performance liquid chromatographic assay for the determination of the chemical stability of bethanechol chloride in PCCA SuspendIt was validated. Suspensions of bethanechol chloride were prepared from the tablets in PCCA SuspendIt at 1-mg/mL and 5-mg/mL concentrations, selected to represent a range within which the drug is commonly dosed. Samples were stored in amber plastic prescription bottles at room temperature (25°C). Samples were assayed initially, and on the following time points (days): 14, 30, 60, 90, and 180. Physical data such as pH and appearance were also noted. Microbiological stability was tested. A stable extemporaneous product is defined as one that retains at least 90% of the initial drug concentration throughout the sampling period and is protected against microbial growth. Using this criterion, no significant degradation of the bethanechol chloride was observed over the 180-day test period for either concentration at room temperature. Drug concentrations were at, or above 93% of initial values for both brands of commercially available tablets. No microbial growth was observed. pH values remained fairly constant. This study demonstrates that bethanechol chloride tablets are physically, chemically, and microbiologically stable in PCCA SuspendIt for 180 days at room temperature at both concentrations studied, thus providing a viable, compounded alternative for bethanechol chloride in a liquid dosage form, with an extended BUD to meet patient needs.

The effect of bethanechol on tracheobronchomalacia in preterm infants with bronchopulmonary dysplasia: a retrospective cohort study.

OBJECTIVE: Bethanechol has demonstrated improvement in trachealis tone in animal models, but no trials have studied efficacy in infants. This study aimed to examine if bethanechol improves a standardized pulmonary severity score (PSS) in infants with severe bronchopulmonary dysplasia with a diagnosis of tracheobronchomalacia (TBM). STUDY DESIGN: This retrospective cohort study evaluated cases treated with bethanechol matched with controls who did not receive bethanechol. TBM was diagnosed by dynamic computography. Daily PSS was recorded for each infant from 40 to 55 weeks post-menstrual age. RESULTS: Cases' mean PSS change was 21% lower than the controls' mean PSS change pre- and post-bethanechol (95% CI -40%, -2%) by paired t-test (p = 0.03). Matched differences (controls' PSS - cases' PSS) demonstrated greater mean PSS difference post-bethanechol compared to pre-bethanechol 0.17, (95% CI 0.05, 0.29) by paired t-test (p = 0.009). CONCLUSION: Infants with TBM treated with bethanechol compared to those not treated had a lower PSS reflecting improved respiratory status.

Vagal afferent fibres determine the oxytocin-induced modulation of gastric tone.

Oxytocin (OXT) inputs to the dorsal vagal complex (DVC; nucleus of the tractus solitarius (NTS) dorsal motor nucleus of the vagus (DMV) and area postrema) decrease gastric tone and motility. Our first aim was to investigate the mechanism(s) of OXT-induced gastric relaxation. We demonstrated recently that vagal afferent inputs modulate NTS-DMV synapses involved in gastric and pancreatic reflexes via group II metabotropic glutamate receptors (mGluRs). Our second aim was to investigate whether group II mGluRs similarly influence the response of vagal motoneurons to OXT. Microinjection of OXT in the DVC decreased gastric tone in a dose-dependent manner. The OXT-induced gastric relaxation was enhanced following bethanechol and reduced by l-NAME administration, suggesting a nitrergic mechanism of gastroinhibition. DVC application of the group II mGluR antagonist EGLU induced a gastroinhibition that was not dose dependent and shifted the gastric effects of OXT to a cholinergic-mediated mechanism. Evoked and miniature GABAergic synaptic currents between NTS and identified gastric-projecting DMV neurones were not affected by OXT in any neurones tested, unless the brainstem slice was (a) pretreated with EGLU or (b) derived from rats that had earlier received a surgical vagal deafferentation. Conversely, OXT inhibited glutamatergic currents even in naive slices, but their responses were unaffected by EGLU pretreatment. These results suggest that the OXT-induced gastroinhibition is mediated by activation of the NANC pathway. Inhibition of brainstem group II mGluRs, however, uncovers the ability of OXT to modulate GABAergic transmission between the NTS and DMV, resulting in the engagement of an otherwise silent cholinergic vagal neurocircuit.