Sucralfate

Bioactive sucralfate-based microneedles promote wound healing through reprogramming macrophages and protecting endogenous growth factors

Impaired wound healing due to insufficient cell proliferation and angiogenesis is a significant physical and psychological burden to patients worldwide. Therapeutic delivery of exogenous growth factors (GFs) at high doses for wound repair is non-ideal as GFs have poor stability in proteolytic wound environments. Here, we present a two-stage strategy using bioactive sucralfate-based microneedle (SUC-MN) for delivering interleukin-4 (IL-4) to accelerate wound healing. In the first stage, SUC-MN synergistically enhanced the effect of IL-4 through more potent reprogramming of pro-regenerative M2-like macrophages via the JAK-STAT pathway to increase endogenous GF production. In the second stage, sucralfate binds to GFs and sterically disfavors protease degradation to increase bioavailability of GFs. The IL-4/SUC-MN technology accelerated wound healing by 56.6 % and 46.5 % in diabetic mice wounds and porcine wounds compared to their respective untreated controls. Overall, our findings highlight the innovative use of molecular simulations to identify bioactive ingredients and their incorporation into microneedles for promoting wound healing through multiple synergistic mechanisms.

Anti-ulcer effects of natural honey against indomethacin induced gastric ulcer in rats

Background and objectives: Non-steroidal anti-inflammatory drugs (NSAIDs) are the leading cause of peptic ulcer disease (PUD). Drug such as proton pump inhibitors or cytoprotective agents used to treat PUD have several adverse effects. Therefore, interest in alternative therapies like honey has increased due to fewer side effects, ease of accessibility and affordability. This study determined the anti-ulcer effect of natural honey against indomethacin induced ulcer in rats. Materials and Methods: This experimental study was conducted on albino rats. Rats were assigned to four groups (Group1 to 4) and each group consisted of six rats. Gr1 received indomethacin (60 mg/kg) only and Gr2, 3 and 4 were pre-treated with assigned doses of sucralfate, honey, and honey + sucralfate respectively for 7 days. The effects of experimental agents were assessed by ulcer score, ulcer index (UI), percentage protective ratio (PPR). Effect of honey, sucralfate and honey plus sucralfate mixture was compared against high dose indomethacin induced gastric ulcer in rats. Results: UI significantly (p < 0.001) reduced in sucralfate, (0.67 ± 0.82), honey (0.83 ± 0.98) and honey + sucralfate (0.17 ± 0.41) treated group compared to only indomethacin treated group (4 ± 0.63).The PPR of sucralfate, honey and honey + sucralfate was 83.25%, 79.25% and 95.75%, respectively. Conclusions: The study showed that honey had anti-ulcer properties against the indomethacin-induced gastric ulcers and the effect is potentiated when used with sucralfate. Honey may be used to protect the gastric mucosa against NSAIDs. IMC J Med Sci 2022; 16(2): 009. DOI: https://doi.org/10.55010/imcjms.16.019 *Correspondence: Md. Faizul Ahasan, Department of Pharmacology, Ibrahim Medical College, 1/A Ibrahim Sarani, Segunbagicha, Dhaka 1000, Bangladesh. Email: arronnoo_shuvro@live.com

Comparison of topical sucralfate with dexpanthenol in rat wound model

Wound healing is a dynamic process initiated in response to injury. There are many factors that have detrimental effects on the wound healing process. Numerous studies have been conducted for improving wound healing processes. Dexpanthenol is widely used to accelerate wound healing. Sucralfate is used for the treatment of peptic ulcers. We aimed to compare the efficacy of topical Dexpanthenol and Sucralfate in an experimental wound model in rats via histopathological examinations and immune histochemical determinations, as well, to evaluate their effects on EGF levels. Three different groups were formed: the Control Group, the Dexpanthenol Group and the Sucralfate Group. Full-thickness skin wounds were created on the back of each rat and isotonic saline was applied to the wounds of the rats in the control group, Bepanthol^® cream was applied in Dexpanthenol Group and 10% Sucralfate cream was applied in Sucralfate Group, once a day. On the 7th, 14th and 21st days the wounds were measured and seven rats from each group were sacrificed and the wounds were excised for histopathological examination. Sucralfate increased wound healing rates by increasing neovascularization, fibroblast activation, reepithelialization and collagen density, as well as dexpanthenol. Our study revealed that the dexpanthenol and sucralfate groups were better than the control group in terms of their effects on wound healing, however there was no statistically significant difference among these two groups. Sucralfate improves EGF expression in skin wounds and has positive results on skin wound healing comparable to dexpanthenol.

Design Strategy for a Hydroxide-Triggered pH-Responsive Hydrogel as a Mucoadhesive Barrier to Prevent Metabolism Disorders

Excess nutrient uptake is one of the main factors of complications related to metabolism disorders. Therefore, efforts have emerged to modulate nutrient transport in the intestine. However, current approaches are mainly invasive interventions with various side effects. Here, a pH-responsive hydrogel is formulated by acidifying the hydroxide compounds within sucralfate to allow electrostatic interactions between pectin and aluminum ions. The pH responsiveness relies on the alternation of cations and hydroxide species, providing reversible shifting from a hydrogel to a complex coacervate system. It acts as a transient physical barrier coating to inhibit intestinal absorption and changes the viscosity and barrier function in different parts of the gastrointestinal tract, showing enhanced mucoadhesive properties. The therapeutic hydrogel remarkably lowers the immediate blood glucose response by modulating nutrient contact with bowel mucosa, suggesting potential in treating diabetes. In addition, it significantly reduces weight gain, fat accumulation, and hepatic lipid deposition in rodent models. This study provides a novel strategy for fabricating pH-responsive hydrogels, which may serve as a competent candidate for metabolism disorder management.

Gastro-esophageal reflux disease: limits of medical treatment and surgical indications

Proton-pump inhibitors (PPI) have long been considered as the ideal treatment for gastroesophageal reflux disease (GERD), and their limitations and side effects have revealed a need for new therapeutic approaches. At present, the therapeutic gains achieved are relatively small or limited to groups of patients with specific characteristics. This article updates the contributions, indications, and limitations of pharmacological, endoscopic, and surgical treatment.

Effective Use of Topical Sucralfate in the Conservative Management of Expanded Gastrostomy Tract Reduction

Sucralfate is a common medication used to treat duodenal ulcers, gastric ulcers, and gastritis. The off-label use of topical sucralfate has been described in the literature to induce wound healing in epithelial injury. Yet, current literature lacks clinical depictions in the application of sucralfate to treat a common gastrostomy tube complication, that of a dilated gastrostomy site. We present a case report of a medically complex pediatric patient where topical sucralfate was applied to reduce the size of a large gastrostomy stomal defect. Sucralfate was used to reduce healing time and allow introduction of a new gastrostomy device through the same stomal opening without the need for additional procedures or surgeries.

Sucralfate as an Adjunct to Analgesia to Improve Oral Intake in Children With Infectious Oral Ulcers: A Randomized, Double-Blind, Placebo-Controlled Trial

STUDY HYPOTHESIS

We hypothesized that sucralfate along with oral analgesics (acetaminophen or ibuprofen) administered in the emergency department leads to a clinically significant improvement in oral intake in children with acute infectious oral ulcers.

METHODS

This was a randomized, double-blind, placebo-controlled trial of sucralfate versus placebo conducted between 2017 and 2018 in an urban pediatric emergency department. Children aged 6 months to 5 years with acute, infectious oral ulcers and poor oral intake received either acetaminophen at 15 mg/kg or ibuprofen at 10 mg/kg and were then randomized to receive sucralfate at 20 mg/kg per dose up to 1 g or a placebo solution. The primary outcome was oral fluid intake within 60 minutes of medication administration. The secondary outcomes were repeat ED visits, length of stay in ED, intravenous hydration rate, admission rate, adverse event rate, and emergency physician's determination of the adequacy of oral intake.

RESULTS

One hundred subjects with mild dehydration (clinical dehydration score of 1) and a median age of 1.38 years were enrolled and analyzed (49 in the sucralfate group and 51 in the placebo group). Oral intake 1 hour after drug administration was similar in both the groups: the median intake in the sucralfate group was 9.7 mL/kg and 10.7 mL/kg in the placebo group (difference -1 mL/kg; 95% confidence interval [CI] -2.0 to 4.8). According to the emergency physician's report, the secondary outcomes were significant only for adequate oral intake: 71% in the sucralfate group versus 88% in the placebo group (difference -16.8%; 95% CI -32.2 to -1.4).

CONCLUSION

Sucralfate as an adjunct to oral analgesics was not superior to placebo in improving oral intake in children with acute oral infectious ulcers.

Review of brachytherapy complications - Upper gastrointestinal tract

While brachytherapy applications are not widely used for cancer diagnoses in the upper GI tract (including the esophagus, liver, stomach, and pancreas), they have a clear role in palliation and symptom management and occasionally definitive locoregional treatment. With the increasing use of image-guided techniques, the incidence of side effects and complications has shown to be lower than many other alternative treatment modalities, making brachytherapy approaches a preferred treatment option. This review examines procedural complications and acute and chronic adverse effects from radiation associated with esophageal, hepatobiliary, and pancreatic brachytherapy and their management.

Systematic review of antimicrobials, mucosal coating agents, anesthetics, and analgesics for the management of oral mucositis in cancer patients and clinical practice guidelines

PURPOSE

To update the clinical practice guidelines for the use of antimicrobials, mucosal coating agents, anesthetics, and analgesics for the prevention and/or treatment of oral mucositis (OM).

METHODS

A systematic review was conducted by the Mucositis Study Group of the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO). The body of evidence for each intervention, in each cancer treatment setting, was assigned an evidence level. The findings were added to the database used to develop the 2014 MASCC/ISOO clinical practice guidelines. Based on the evidence level, the following guidelines were determined: Recommendation, Suggestion, and No Guideline Possible.

RESULTS

A total of 9 new papers were identified within the scope of this section, adding to the 62 papers reviewed in this section previously. A new Suggestion was made for topical 0.2% morphine for the treatment of OM-associated pain in head and neck (H&N) cancer patients treated with RT-CT (modification of previous guideline). A previous Recommendation against the use of sucralfate-combined systemic and topical formulation in the prevention of OM in solid cancer treatment with CT was changed from Recommendation Against to No Guideline Possible. Suggestion for doxepin and fentanyl for the treatment of mucositis-associated pain in H&N cancer patients was changed to No Guideline Possible.

CONCLUSIONS

Of the agents studied for the management of OM in this paper, the evidence supports a Suggestion in favor of topical morphine 0.2% in H&N cancer patients treated with RT-CT for the treatment of OM-associated pain.

Effect of sucralfate against hydrochloric acid-induced dental erosion

OBJECTIVE

Devising effective measures for the prevention of hydrochloric acid (HCl)-induced erosion is of great significance. This is even more important in dentine, in which products have limited diffusion. Therefore, agents that can bind to proteins forming an acid-resistant gel-like coat, such as sucralfate, may stand out as a promising alternative. This study investigated the protective effect of sucralfate suspensions against HCl-induced dental erosion.

MATERIALS AND METHODS

In the first experiment, hydroxyapatite (HAp) crystals were pre-treated with a commercial sucralfate suspension (CoSS, pH 5.9), a stannous-containing sodium fluoride solution (NaF/SnCl₂ pH 4.5), two prepared sucralfate suspensions (PrSS, pH 5.9 and 4.5), or deionized water (DI, control). HAp dissolution was measured using a pH-stat system. In a subsequent experiment, embedded/polished enamel and root dentine slabs were allocated into five groups to be treated with one of the tested substances prior to and during erosion-remineralization cycles (HCl-2 min + artificial saliva 60 min, two times per day, 5 days). Surface loss was assessed profilometrically. Data were analyzed by ANOVA and Tukey's tests.

RESULTS

HAp dissolution was as follows: NaF/SnCl₂ < CoSS < PrSS/pH 4.5, while PrSS/pH 5.9 = DI and both did not differ from CoSS and PrSS/pH 4.5. In enamel, surface loss did not differ between CoSS and PrSS/pH 4.5, with both having lower surface loss than PrSS/pH 5.9 and DI and NaF/SnCl₂ differing only from DI. In root dentine, surface loss was as follows: CoSS < PrSS/pH 5.9 < (NaF/SnCl₂ = DI), while PrSS/pH 4.5 = CoSS = PrSS/pH 5.9.

CONCLUSION

Sucralfate suspension provided anti-erosive protection to HCl-induced erosion.

CLINICAL RELEVANCE

Sucralfate may protect teeth against erosion caused by gastric acid.

Therapeutic luminal coating of the intestine

The gastrointestinal tract is the site of most drug delivery and therapeutic interventions for the management and treatment of numerous diseases. However, selective access to its mucosa, especially in the small bowel, is challenging. Here we develop an orally administered gut-coating formulation that provides a transient coating of the bowel. Through a materials screening campaign, we identified a sucrose octasulfate aluminium complex and further engineered the pH-dependent material into a complex coacervate formulation linked via pH-independent electrostatic interaction, which allowed an effective transient physical coating on the gastrointestinal mucosa, independent of gastric acid exposure. We tested the therapeutic values of this technology in two settings. Oral administration of this gut-coating formulation modulated the nutrient contact with bowel mucosa, which lowered the glucose responses in rodent models indicating a potential therapeutic utility in diabetes. Furthermore, the formulation protected biological agents from gastric acid exposure and degradation, which enabled oral delivery to the small bowel mucosa.

Gastroprotectants in small animal veterinary practice - a review of the evidence. Part 1: cyto-protective drugs

Diverse drugs with presumed cytoprotective effect have been used therapeutically in small animal veterinary practice for various gastro-intestinal conditions such as oesophagitis, gastric ulceration, gastritis or chronic gastro-enteropathies. Their efficacy has been doubted in human medicine, raising similar questions in the veterinary field. The aim of this review was to assess the current evidence on the efficacy and safety of these drugs in dogs and cats. Through a systematic review of the literature, we identified 37 articles on the use of misoprostol, sucralfate and other gastroprotectants in dogs and cats. There was evidence to support use of misoprostol in the prevention of aspirin-induced gastroduodenal mucosal injury in dogs, and for use of sucralfate in the prevention of acid-induced oesophagitis in cats. However, the overall quality of evidence supporting the use of these drugs in small animal patients was poor. In contrast, there was evidence of important adverse effects, especially drug interaction and gastro-intestinal signs. We therefore recommend prescribing these drugs with caution until further well-conducted studies reveal a useful gastroprotectant effect.

Sucralfate Prophylaxis of Fluorouracil-Induced Stomatitis

Aims and Background

Various attempts have been made to prevent 5-fluorouracil-induced stomatitis, with unsatisfactory results. Sucralfate is an aluminum hydroxide, complex of sulfated sucrose commonly used in the treatment of gastroduodenal ulcers. We used the compound in a phase II study to reduce and minimize the stomatotoxicity of 5-fluorouracil chemotherapy administered in a multiple-day schedule.

Methods

Fifty-two patients entered the study, and 129 cycles of chemotherapy were evaluated. Seven patients refused sucralfate rinses for taste intolerance.

Results

A low level of stomatotoxicity was recorded: grade 2 stomatitis was observed after 14 cycles (10.8%) and grade 3 after 3 cycles (2.3%).

Conclusions

Sucralfate administration could have a role in the prevention of 5-fluorouracil-induced stomatitis.

Drug Interactions with Antiulcer Agents: Considerations in the Treatment of Acid-Peptic Disease

All of the antiulcer agents have been implicated in drug interactions. These agents generally influence the absorption, metabolism, or elimination of other medications. However, these interactions can lead to alterations in pharmacodynamic response. The mechanisms by which antiulcer agents produce drug interactions differ among the agents. It is beyond the scope of this article to review all of the drug interactions that have been reported with antiulcer agents. However, it is the intent to provide the reader with a detailed understanding of the mechanisms by which antiulcer agents may interact with other medications and to provide insight into factors that may influence the potential magnitude or clinical consequences of these interactions. An understanding of antiulcer drug interactions will aid pharmacists in assisting clinicians with drug selection and/or monitoring of drug interactions. Specifically, pharmacists can assist with the identification of potential antiulcer drug interactions and develop strategies designed to minimize adverse consequences of these interactions.

Acid suppression therapy and allergic reactions

The development of pharmaceutical agents such as sucralfate, histamine 2 (H2) receptor blockers and proton pump inhibitors (PPIs) reducing gastric acidity has been a mile stone for treatment of dyspeptic disorders. However, due to current prescription habits resulting in overuse of these potent drugs as well as over-the-counter (OTC) availability associated with self-medication, substantial health concern is related to the mechanisms of drug action as well as known side effects influencing gastrointestinal physiology. More than a decade ago the first study appeared reporting an association between anti-ulcer drug intake and food allergy development. Ever since this first report several experimental as well as human studies verified this correlation, demonstrating that acid suppressive drugs not only influence the sensitization capacity of orally ingested proteins, but also represent a risk factor for food allergy patients. Additionally, gastric acid suppression was reported to increase the risk for development of drug hypersensitivity reactions. These consequences of anti-ulcer drug intake might on the one hand be associated with direct influence of these drugs on immune responses. On the other hand reduction of gastric acidity leads to impaired gastrointestinal protein degradation. Nevertheless, also disruption of the gastrointestinal barrier function, changes in microbiome or lack of tolerogenic peptic digests might contribute to the connection between anti-ulcer drug intake and allergic reaction. Therefore, these drugs should only be prescribed based on a precise gastroenterological diagnosis taking into consideration allergological mechanisms to ensure patients' safety.

Acid peptic diseases: pharmacological approach to treatment

Acid peptic disorders are the result of distinctive, but overlapping pathogenic mechanisms leading to either excessive acid secretion or diminished mucosal defense. They are common entities present in daily clinical practice that, owing to their chronicity, represent a significant cost to healthcare. Key elements in the success of controlling these entities have been the development of potent and safe drugs based on physiological targets. The histamine-2 receptor antagonists revolutionized the treatment of acid peptic disorders owing to their safety and efficacy profile. The proton-pump inhibitors (PPIs) represent a further therapeutic advance due to more potent inhibition of acid secretion. Ample data from clinical trials and observational experience have confirmed the utility of these agents in the treatment of acid peptic diseases, with differential efficacy and safety characteristics between and within drug classes. Paradigms in their speed and duration of action have underscored the need for new chemical entities that, from a single dose, would provide reliable duration of acid control, particularly at night. Moreover, PPIs reduce, but do not eliminate, the risk of ulcers in patients taking NSAIDs, reflecting untargeted physiopathologic pathways and a breach in the ability to sustain an intragastric pH of more than 4. This review provides an assessment of the current understanding of the physiology of acid production, a discussion of medications targeting gastric acid production and a review of efficacy in specific acid peptic diseases, as well as current challenges and future directions in the treatment of acid-mediated diseases.

High-potency sucralfate prevents and rapidly reverses chemo-radiation mucositis in a patient with stage 4b head and neck cancer

AIM: To study usefulness of high-potency sucralfate (HPS) in a patient with chemoradiation mucositis and discuss its mechanism of action.

METHODS: HPS, a non-covalently cross-link of sucralfate, cations and bidentate anionic chelators, has a maintains a surface concentration of sucralfate 3 h following administration that is 7-23 fold that possible with standard-potency sucralfate. The accelerated mucosal healing and pain alleviation of HPS in patients with erosive esophageal reflux, prompted its use in this patient with chemoradiation mucositis of the oropharynx and alimentary tract. A literature-based review of the immuno-modulatory effects of sucralfate is discussed.

RESULTS: Within 48 h of intervention: (1) there was complete disappearance of oral mucositis lesions; tenderness with (2) patient-reported disappearance of pain, nausea and diarrhea; patient required (3) no opiate analgesia and (4) no tube-feeding supplements to regular diet. Dysgeusia and xerostomia persisted. A modified Naranjo Questionnaire score of 10 supported the likelihood that HPS intervention caused the observed clinical effects. No adverse reactions noted.

CONCLUSION: In this patient HPS was useful to treat chemo-radiation mucositis of the oropharynx and alimentary tract. HPS may directly or indirectly facilitate an immunomodulatory mechanism involving accelerated growth factor activation, which may be a new target for therapeutic intervention in such patients.

Current pharmacological management of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD), a common disorder with troublesome symptoms caused by reflux of gastric contents into the esophagus, has adverse impact on quality of life. A variety of medications have been used in GERD treatment, and acid suppression therapy is the mainstay of treatment for GERD. Although proton pump inhibitor is the most potent acid suppressant and provides good efficacy in esophagitis healing and symptom relief, about one-third of patients with GERD still have persistent symptoms with poor response to standard dose PPI. Antacids, alginate, histamine type-2 receptor antagonists, and prokinetic agents are usually used as add-on therapy to PPI in clinical practice. Development of novel therapeutic agents has focused on the underlying mechanisms of GERD, such as transient lower esophageal sphincter relaxation, motility disorder, mucosal protection, and esophageal hypersensitivity. Newer formulations of PPI with faster and longer duration of action and potassium-competitive acid blocker, a newer acid suppressant, have also been investigated in clinical trials. In this review, we summarize the current and developing therapeutic agents for GERD treatment.

IBS, NERD and functional dyspepsia are immuno-neuronal disorders of mucosal cytokine imbalances clinically reversible with high potency sucralfate

Irritable bowel syndrome (IBS), non-erosive reflux disorder (NERD), and functional dyspepsia (FD) are best classified as immuno-neuronal disorders of the mucosa or functional mucosal syndromes (FMS). Each appears to be clinically reversible using high potency sucralfate (HPS). In FMS of the GI tract, postprandial nausea, altered motility, discordant peristalsis, vomiting, diarrhea, and hyperalgesia are the clinical expressions of a mucosal imbalance between pro-inflammatory cytokines of up-regulated intra-epithelial lymphocytes (IELs) and feedback anti-inflammatory cytokines tasked with moderating the antigenic response of IELs. Normal functioning GI tract requires an operative balance between pro-inflammatory and anti-inflammatrory cytokines, a balance governed by locally expressed growth factors. The surface concentration of sucralfate can be enhanced 7-23-fold by suspending it in a select concentration of cations and multi-dentate cationic chelators. Increased surface concentration of sucralfate facilitates novel dose effects which include efficient activation of growth factors, quiescence of gated-nociceptor firing and resultant restoration of normal GI function.

[The Mexican consensus on gastroesophageal reflux disease. Part I]

BACKGROUND

The changes, advances, and new discoveries regarding different aspects of gastroesophageal reflux disease (GERD) have made it necessary to update the Mexican Consensus published in 2002.

AIMS

To elaborate a new Mexican Consensus on GERD.

METHODS

The general project coordinators selected six GERD experts to carry out an extensive review of the literature for the purpose of elaborating statements on the principal aspects of GERD. These were then placed under the consideration of specialists in the study of this disease. Definitive approval by all participants was reached using the modified Delphi method with three rounds of anonymous and iterative voting. The following scale was employed: A- in complete agreement; B- in agreement, but with minor concerns; C- in agreement, but with major concerns; D- in disagreement, but with major concerns; E- in disagreement, but with minor concerns; or F- in complete disagreement. Consensus was declared when 67.00% or more of the participants concurred on a category of agreement (A, B, or C).

RESULTS

A consensus was reached on 160 of the statements upon completion of the voting rounds, with 90.00% concurrence for the majority of them.

CONCLUSIONS

The 2011 Mexican Consensus on Gastroesophageal Disease is a practical and up-to-date consultation tool, providing the opinion of Mexican experts on all the new information available about this disease. It allows there to be homogeneity in diagnostic and therapeutic criteria, all of which serves to benefit our patients.

Prevention and Treatment of Gastrointestinal Complications in Patients on Mechanical Ventilation

There exists a complex, dynamic interaction between mechanical ventilation and the splanchnic vasculature that contributes to a myriad of gastrointestinal tract complications that arise during critical illness. Positive pressure-induced splanchnic hypoperfusion appears to play a pivotal role in the pathogenesis of these complications, the most prevalent of which are stress-related mucosal damage, gastrointestinal hypomotility and diarrhea. Furthermore, characteristics of the splanchnic vasculature make the gastrointestinal tract vulnerable to adverse effects related to positive pressure ventilation. While most of these complications seen in mechanically ventilated patients are reflections of altered gastrointestinal physiology, some may be attributed to medical interventions instituted to treat critical illness. Since maintenance of normal hemodynamics cannot always be achieved, pharmacologic prophylactic therapy has become a mainstay in the prevention of gastrointestinal complications in the intensive care unit. Improved understanding of the systemic effects of mechanical ventilation and greater application of lung-protective ventilatory strategies may potentially minimize positive pressure-induced reductions in splanchnic perfusion, systemic cytokine release and, consequently, reduce the incidence of gastrointestinal complications associated with mechanical ventilation. Herein, we discuss the pathophysiology of gastrointestinal complications associated with mechanical ventilation, summarize the most prevalent complications and focus on preventive strategies and available treatment options for these complications. The most common causes of gastrointestinal hemorrhage in mechanically ventilated patients are bleeding from stress-related mucosal damage and erosive esophagitis. In general, histamine H(2) receptor antagonists and proton pump inhibitors prevent stress-related mucosal disease by raising the gastric fluid pH. Proton pump inhibitors tend to provide more consistent pH control than histamine H(2) receptor antagonists. There is no consensus on the drug of choice for stress ulcer prophylaxis with several meta-analyses providing conflicting results on the superiority of any medication. Prevention of erosive esophagitis include careful use of nasogastric tubes and institution of strategies that improve gastric emptying. Many mechanically ventilated patients have gastrointestinal hypomotility and diarrhea. Treatment options for gastrointestinal motility are limited, thus, preventive measures such as correction of electrolyte abnormalities and avoidance of medications that impair gastrointestinal motility are crucial. Treatment of diarrhea depends on the underlying cause. When associated with Clostridium difficile infection antibacterial therapy should be discontinued, if possible, and treatment with oral metronidazole should be initiated.More studies are warranted to better understand the systemic effects of mechanical ventilation on the gastrointestinal tract and to investigate the impact of lung protective ventilatory strategies on gastrointestinal complications.

A review of stress-related mucosal disease

OBJECTIVE

To review and summarize the human and veterinary literature regarding stress-related mucosal disease (SRMD) pathogenesis, patient risk factors, and therapeutic options for prophylaxis and treatment.

ETIOLOGY

SRMD is a common sequela of critical illness in human patients. Development of SRMD results from splanchnic hypoperfusion, reperfusion injury, and exposure of the gastric mucosa to acid, pepsin, and bile acids following breakdown of the gastric mucosal defense system. Human patients with the highest risk of stress ulceration include those with respiratory failure necessitating mechanical ventilation greater than 48 h or coagulopathy. Currently, little is known about the incidence and pathophysiology of SRMD in critically ill veterinary patients.

DIAGNOSIS

A presumptive diagnosis can be made in high-risk patient populations following detection of occult or gross blood in nasogastric tube aspirates, hematemesis, or melena. Definitive diagnosis is achieved via esophagogastroduodenoscopy. Lesions are localized to the acid-producing portions of the stomach, the fundus, and body.

THERAPY

Therapy is aimed at optimization of tissue perfusion and oxygenation. Pharmacologic interventions are instituted to increase intraluminal pH and augment natural gastric defenses. Histamine(2)-receptor antagonists, proton pump inhibitors, and sucralfate are the mainstays of therapy. In people, clinically significant bleeding may necessitate additional interventions (eg, packed red blood cell transfusions, endoscopic, or surgical hemostasis).

PROGNOSIS

Mortality is increased in people with clinically significant bleeding compared to those patients who do not bleed. Institution of prophylaxis is recommended in high-risk patients. However, no consensus exists regarding initiation of prophylaxis, preference of frontline drug class, or indication for discontinuation of therapy. The prognosis of veterinary patients with SRMD remains unknown at this time.

Gastrointestinal prophylaxis in neurocritical care

The aim of this study is to review and summarize the relevant literature regarding pharmacologic and non-pharmacologic methods of prophylaxis against gastrointestinal (GI) stress ulceration, and upper gastrointestinal bleeding in critically ill patients. Stress ulcers are a known complication of a variety of critical illnesses. The literature regarding epidemiology and management of stress ulcers and complications thereof, is vast and mostly encompasses patients in medical and surgical intensive care units. This article aims to extrapolate meaningful data for use with a population of critically ill neurologic and neurosurgical patients in the neurological intensive care unit setting. Studies were identified from the Cochrane Central Register of controlled trials and NLM PubMed for English articles dealing with an adult population. We also scanned bibliographies of relevant studies. The results show that H(2)A, sucralfate, and PPI all reduce the incidence of UGIB in neurocritically ill patients, but H(2)A blockers may cause encephalopathy and interact with anticonvulsant drugs, and have been associated with higher rates of nosocomial pneumonias, but causation remains unproven and controversial. For these reasons, we advocate against routine use of H(2)A for GI prophylaxis in neurocritical patients. There is a paucity of high-level evidence studies that apply to the neurocritical care population. From this study, it is concluded that stress ulcer prophylaxis among critically ill neurologic and neurosurgical patients is important in preventing ulcer-related GI hemorrhage that contributes to both morbidity and mortality. Further, prospective trials are needed to elucidate which methods of prophylaxis are most appropriate and efficacious for specific illnesses in this population.

Efficacy of low-level laser therapy and aluminum hydroxide in patients with chemotherapy and radiotherapy-induced oral mucositis

This study evaluated the efficacy of low-level laser therapy (LLLT) and aluminum hydroxide (AH) in the prevention of oral mucositis (OM). A prospective, comparative and non-randomized study was conducted with 25 patients with head and neck cancer subjected to radiotherapy (RT) or radiochemotherapy (RCT). Twelve patients received LLLT (830 nm, 15 mW, 12 J/cm²) daily from the 1st day until the end of RT before each sessions during 5 consecutive days, and the other 13 patients received AH 310 mg/5 mL, 4 times/day, also throughout the duration of RT, including weekends. OM was measured using an oral toxicity scale (OTS) and pain was measured using the visual analogue scale (VAS). EORTC questionnaires were administered to the evaluate impact of OM on quality of life. The LLLT group showed lower mean OTS and VAS scores during the course of RT. A significant difference was observed in pain evaluation in the 13th RT session (p=0.036). In both groups, no interruption of RT was needed. The prophylactic use of both treatments proposed in this study seems to reduce the incidence of severe OM lesions. However, the LLLT was more effective in delaying the appearance of severe OM.

Deep Vein Thrombosis and Stress Ulcer Prophylaxis in the Intensive Care Unit

Deep vein thrombosis (DVT) and stress gastric ulcers can be serious complications in patients admitted to the intensive care unit. This review discusses the risk factors associated with the development of DVT and stress-related mucosal disease (SRMD), evaluates the available literature on current options for DVT and stress ulcer prophylaxis, and examines the associated adverse effects and optimal duration of therapy.

Stress Ulcer Prophylaxis in the New Millennium!

Clinical trials conducted in the latter part of the past millennium suggested that bleeding from gastric stress ulceration was an important cause of morbidity and mortality in intensive care unit (ICU) patients and that treatment with acid-suppressive therapy reduced the risk of clinically significant bleeding. Stress ulcer prophylaxis therefore became regarded as the standard of care in all ICU patients. However, more recent clinical trials have demonstrated that the risk of clinically significant bleeding is extremely low (about 1%) and not altered by the use of acid-suppressive therapy. Furthermore, a critical review of the “historical” clinical trials, as well as the data from experimental and more recent clinical trials, suggests that enteral feeding (gastric) is at least as effective as acid-suppressive therapy in the prevention of gastric stress ulceration and is the prophylactic measure of choice in most ICU patients.

Guidelines for prevention of NSAID-related ulcer complications

Guidelines for clinical practice are intended to indicate preferred approaches to medical problems as established by scientifically valid research. Double-blind, placebo-controlled studies are preferable, but compassionate use reports and expert review articles are used in a thorough review of the literature conducted through Medline with the National Library of Medicine. Only when data that will not withstand objective scrutiny are available is a recommendation identified as a consensus of experts. Guidelines are applicable to all physicians who address the subject, without regard to specialty training or interests, and are intended to indicate the preferable, but not necessarily the only, acceptable approach to a specific problem. Guidelines are intended to be flexible and must be distinguished from standards of care, which are inflexible and rarely violated. Given the wide range of specifics in any health-care problem, the physician must always choose the course best suited to the individual patient and the variables in existence at the moment of decision. These guidelines were developed under the auspices of the American College of Gastroenterology by a committee of experts in the field, reviewed by its Practice Parameters Committee, and approved by the Board of Trustees. The recommendations of these guidelines are therefore considered valid at the time of production based on the data available. New developments in medical research and practice pertinent to each guideline will be reviewed at an established time and indicated at publication to assure continued validity. Owing to the volume of new data on the subject of non-steroidal anti-inflammatory drug (NSAID)-related injury to the upper gastrointestinal tract, i.e., the advent of cyclooxygenase (COX)-2 inhibitors, new data on interactions between these agents, as well as traditional NSAIDs, with aspirin and H. pylori, it was elected by the Committee to confine these guidelines to upper gastrointestinal (GI) injury and to leave post-duodenal injury as the subject of a separate guideline.

The role of protein digestibility and antacids on food allergy outcomes

Digestion assays with simulated gastric fluid have been introduced for characterization of food proteins to imitate the effect of stomach proteolysis on dietary compounds in vitro. By using these tests, dietary proteins can be categorized as digestion-resistant class 1 (true allergens triggering direct oral sensitization) or as labile class 2 allergens (nonsensitizing elicitors). Thus the results of these digestion assays mirror situations of intact gastric proteolysis. Alterations in the gastric milieu are frequently experienced during a lifetime either physiologically in the very young and the elderly or as a result of gastrointestinal pathologies. Additionally, acid-suppression medications are frequently used for treatment of dyspeptic disorders. By increasing the gastric pH, they interfere substantially with the digestive function of the stomach, leading to persistence of labile food protein during gastric transit. Indeed, both murine and human studies reveal that antiulcer medication increases the risk of food allergy induction. Gastric digestion substantially decreases the potential of food proteins to bind IgE, which increases the threshold dose of allergens required to elicit symptoms in patients with food allergy. Thus antiulcer agents impeding gastric protein digestion have a major effect on the sensitization and effector phase of food allergy.

Sucralfate prevents the delay of wound repair in intestinal epithelial cells by hydrogen peroxide through NF-kappaB pathway

BACKGROUND

Recent studies have shown that sucralfate (SF) has therapeutic effects on colonic inflammation in ulcerative colitis. The aim of this study was to clarify the function of SF for wound repair in intestinal epithelial cells (IEC).

METHODS

(1) Activation of signal proteins [ERK1/2 mitogen-activated protein kinase (MAPK), IkappaB-alpha] in IEC-6 cells after stimulation with 10(-4) M potassium sucrose octasulfate (SOS), which is the functional element of SF, was assessed by Western blot. (2) Induction of transforming growth factor (TGF)-beta1, TGF-alpha, EGF, and cyclooxygenase-2 (COX-2) mRNA after stimulation of IEC-6 cells with SOS was assessed by reverse transcriptase-polymerase chain reaction. (3) IEC-6 cells were wounded and cultured for 24 h with various concentrations of SOS in the absence or presence of 20 microM H(2)O(2). Epithelial migration or proliferation was assessed by counting migrating cells or bromodeoxyuridine (BrdU)-positive cells across the wound border.

RESULTS

(1) SOS activated IkappaB-alpha, but it did not activate ERK1/2 MAPK. (2) SOS enhanced the expression of COX-2 mRNA, but it did not change the mRNA expression of other growth factors. (3) SOS did not enhance wound repair in IEC-6 cells, but it decreased the number of dead cells (maximum, 74%) (P < 0.01) in a dose-dependent manner and prevented the diminishment of epithelial migration (maximum, 61%) (P < 0.01) and proliferation (maximum, 37%) (P < 0.05) induced by H(2)O(2). These functions of SOS were suppressed by the NF-kappaB and COX-2 inhibitors.

CONCLUSIONS

SOS prevented the delay of wound repair in IEC-6 cells induced by H(2)O(2), probably through induction of COX-2 and an anti-apoptotic mechanism. These effects of SOS might be given through the activation of the NF-kappaB pathway.

Colitis due to Clostridium difficile toxins: underdiagnosed, highly virulent, and nosocomial

Clostridium difficile colitis is a major complication of antibiotic therapy. Antibiotics cause a reduction in bacteria that normally reside in the colon. If an antibiotic-treated patient ingests C. difficile bacteria, this organism may proliferate in the colon because it is resistant to most antibiotics and because it does not have to compete with the normal bacteria for nutrients. If the C. difficile organism has the gene for toxin production, the toxin can produce a colitis. In addition to antibiotics, other proposed risk factors for development of C. difficile colitis include advanced age, contact with infected patients and with their health care providers, impaired immune function, suppression of gastric acid secretion by a proton pump inhibitor, and postpyloric tube feeding. Many of the risk factors become simultaneously focused on patients admitted to the hospital. The incidence of C. difficile disease has been rising, and strains have become more virulent. In some forms of the disease, the patient doesn't have diarrhea, and in such patients C. difficile can be deadly but difficult to diagnose. The standard treatment, with metronidazole or vancomycin, fails to work in up to 25% of patients with the fulminant form of colitis. Since C. difficile causes only 20% of cases of antibiotic-associated diarrhea, a specific test is needed to diagnose this organism. Toxigenic cultureis highly specific but not available at most institutions. The tests that are available--enzyme-linked immunosorbent assay and fecal cytotoxicity assay--have high false-negative rates, even in patients with severe clinical disease, creating a diagnostic dilemma. The only proven way to reduce the risk of C. difficile disease is implementation of an antibiotic management program in conjunction with enhanced infection control procedures.

In vitro study of the adsorption characteristics of drugs

The adsorption characteristics of eight adsorbents, cholestyramine, colestimide, aluminum silicate, sucralfate, aluminum hydroxide, calcium polystyrene sulfonate, carbon sphere and medicinal carbon, on the drugs such as methotrexate, antidepressants, mizoribine and ciprofloxacin hydrochloride were investigated in vitro. Medicinal carbon showed an excellent adsorption of all the tested drugs while the carbon spheres showed a high but slow adsorption characteristic. Cholestyramine and colestimide showed a higher adsorption in methotrexate than the other adsorbents. Aluminum silicate and calcium polystyrene sulfonate showed higher adsorption in four antidepressants, clomipramine hydrochloride, imipramine hydrochloride, mianserin hydrochloride and trazodone hydrochloride. In mizoribine, there were no adsorbents that showed higher adsorption except for the medicinal carbon. In ciprofloxacin hydrochloride, aluminum preparations and calcium polystyrene sulfonate showed higher adsorption characteristics. It is suggested that several adsorbents are potentially useful treatments for drug overdoses, but that these adsorbents have the possibility of decreasing the effects of the co-administered medicines.

The effectiveness of sucralfate against stricture formation in experimental corrosive esophageal burns

PURPOSE

In this study, the effectiveness of sucralfate against stricture formation in experimental corrosive esophageal burn is reported.

METHODS

Sixty-four Swiss albino adult male rats were divided into three groups, group A (control; n, 7), group B (esophageal burn induced but not treated; n, 25), and group C (esophageal burn induced and treated with sucralfate, n, 32). Groups B and C were further subdivided into subgroups for evaluation on days 2, 7, and 28. A standard esophageal burn was performed by the method of Gehanno, using 50% NaOH. Oral sucralfate treatment was given to group C at a dosage of 50 mg/100 g twice daily. The rats were then killed after 2, 7, or 28 days. Levels of tissue hydroxyproline were measured in excised abdominal esophageal segments, and a histopathological evaluation was performed with hematoxylin-eosin and Masson's trichrome staining.

RESULTS

The tissue hydroxyproline levels were significantly lower in group C than in group B (P = 0.017). There was a significant difference in the stenosis index between groups B and C (P = 0.016). When compared with group B, the collagen deposition in the submucosa and tunica muscularis was significantly lower in group C (P = 0.02).

CONCLUSION

Sucralfate has an inhibitory effect on stricture formation in experimental corrosive burns and can be used in the treatment of corrosive esophageal burns to enhance mucosal healing and suppress stricture formation.

Anti‐ulcer drugs promote IgE formation toward dietary antigens in adult patients

Recently, we have demonstrated that anti-ulcer drugs, such as H2-receptor blockers and proton pump inhibitors, promote the development of immediate type food allergy toward digestion-labile proteins in mice. The aim of this study was to examine the allergological relevance of these findings in humans. In an observational cohort study, we screened 152 adult patients from a gastroenterological outpatient clinic with negative case histories for atopy or allergy, who were medicated with H2-receptor blockers or proton pump inhibitors for 3 months. IgE reactivities to food allergens before and after 3 months of anti-acid treatment were compared serologically. Ten percent of the patients showed a boost of preexisting IgE antibodies and 15% de novo IgE formation toward numerous digestion-labile dietary compounds, like milk, potato, celery, carrots, apple, orange, wheat, and rye flour. Thus, the relative risk to develop food-specific IgE after anti-acid therapy was 10.5 (95% confidence interval: 1.44-76.48). The long-term effect was evaluated 5 months after therapy. Food-specific IgE could still be measured in 6% of the patients, as well as significantly elevated serum concentrations of ST2, a Th2-specific marker. An unspecific boost during the pollen season could be excluded, as 50 untreated control patients revealed no changes in their IgE pattern. In line with our previous animal experiments, our data strongly suggest that anti-ulcer treatment primes the development of IgE toward dietary compounds in long-term acid-suppressed patients.

Clinically significant gastrointestinal bleeding in critically ill patients with and without stress-ulcer prophylaxis

OBJECTIVE

To compare the rates of clinically significant gastrointestinal bleeding and the number of blood units and endoscopies required for gastrointestinal hemorrhage between patients receiving or not receiving stress-ulcer prophylaxis.

DESIGN

Historical observational study comparing two consecutive periods: with (phase 1) and without stress-ulcer prophylaxis (phase 2).

DESIGN AND SETTING

A 17-bed intensive care unit in a university teaching hospital. PATIENTS. In phase 1 there were 736 patients and in phase 2737. Those in the two phases were comparable in age and reason for admission; clinically significant gastrointestinal bleeding rates did not differ between the two phases, but patients in phase 2 were more severely ill.

MEASUREMENTS AND RESULTS

Comparable numbers of blood units were transfused per bleeding patient in the two phases, especially for patients with significant gastrointestinal bleeding. During each phase 19 fibroscopies were performed for significant bleeding, and two patients required surgery. The clinically significant gastrointestinal bleeding rate and outcome did not differ in patients with at least one risk factor. Total expenditures directly related to gastrointestinal bleeding were similar during the two phases; the total cost incurred by stress-ulcer prophylaxis was estimated at 6700.

CONCLUSIONS

Our results suggest that stress-ulcer prophylaxis does not influence the clinically significant gastrointestinal bleeding rate in intensive care unit patients or the cost of its management.

Gastric and duodenal ulcers during pregnancy

The frequency, symptoms, and complication rate of PUD seem to decrease during pregnancy. Yet clinicians often have to treat dyspepsia or pyrosis of undetermined origin during pregnancy because the frequency of pyrosis significantly increases during pregnancy, and clinicians reluctantly perform EGD during pregnancy for pyrosis to differentiate reliably between GERD and PUD. Dyspepsia or pyrosis during pregnancy is initially treated with dietary and lifestyle modifications. If the symptoms do not remit with these modifications, sucralfate or antacids, preferably magnesium-containing or aluminum-containing antacids, should be administered. Histamine2 receptor antagonists are recommended when symptoms are refractory to antacid or sucralfate therapy. Ranitidine seems to be a relatively safe H2 receptor antagonist. If symptoms continue despite H2 receptor antagonist therapy, the patient should be evaluated for possible EGD or PPI therapy. Pregnant women with hemodynamically significant upper gastrointestinal bleeding or other worrisome clinical findings should undergo EGD. Indications for surgery include ulcer perforation, ongoing active bleeding from an ulcer requiring transfusion of six or more units of packed erythrocytes, gastric outlet obstruction refractory to intense medical therapy, and a malignant gastric ulcer without evident metastases.

The effect of oral sucralfate on the acute proctitis associated with prostate radiotherapy: a double-blind, randomized trial

PURPOSE

Acute rectal complications occur in the majority of patients receiving external-beam radiotherapy for carcinoma of the prostate. Sucralfate has been proposed to reduce radiation-induced mucosal injury by forming a protective barrier on ulcer bases, binding local growth factors, and stimulating angiogenesis. However, there is conflicting clinical evidence as to whether sucralfate, taken prophylactically during radiotherapy, can ameliorate the symptoms of acute radiation proctitis.

METHODS AND MATERIALS

A double-blind randomized trial was conducted at four Radiation Oncology Departments in Sydney, Australia, between February 1995 and June 1997. A total of 338 patients with clinically localized prostate cancer receiving small volume radiotherapy, of whom 335 were evaluable, were randomized to receive either 3 g of oral sucralfate suspension or placebo twice a day during radiotherapy. Patients kept a daily record of their bowel symptoms and were graded according to the RTOG/EORTC acute toxicity criteria.

RESULTS

One hundred sixty-four patients received sucralfate and 171 received placebo. Both groups were well balanced with regard to patient, tumor, treatment factors, and baseline symptoms, except that the placebo group had a significantly more liquid baseline stool consistency score (p = 0.004). Patients kept a daily diary of symptoms during radiotherapy. After adjusting for baseline values, there was no significant difference between the two groups with regard to stool frequency (p = 0.41), consistency (p = 0.20), flatus (p = 0.25), mucus (p = 0.54), and pain (p = 0.73). However, there was more bleeding in the sucralfate group, with 64% of patients noticing rectal bleeding, compared with 47% in the placebo group (p = 0.001). There was no significant difference between the two groups with respect to RTOG/EORTC acute toxicity (p = 0.88; sucralfate 13%, 44%, 43% and placebo 15%, 44%, 40% for grade 0, 1, and 2, respectively).

CONCLUSION

This study suggests that oral sucralfate taken prophylactically during radiotherapy does not ameliorate the symptoms of acute radiation proctitis and may increase acute bleeding. The cause of the increased bleeding in the sucralfate group is unclear. As the pathogenesis of acute and late reactions are different, late follow-up, which includes sigmoidoscopic evaluation, is currently being performed on this cohort of patients.

Prevention of mucositis in bone marrow transplantation: a double blind randomised controlled trial of sucralfate

Mucositis is still a leading side effect of high dose chemotherapy and irradiation delivered in autologous and allogeneic bone marrow transplantation. In this double blind randomised study, we tested the efficacy of sucralfate for the prevention of mucositis induced by such conditioning treatments. Treatment was started one day before conditioning regimen and patients were prospectively evaluated. The main endpoint was severe mucositis that was more frequent in the placebo group than in the sucralfate group (47% vs. 29%, P = 0.07). This trend was confirmed after adjustment on total body irradiation (TBI) (P = 0.06), the sole stratification parameter. Interestingly, patients receiving sucralfate showed a significant reduction of diarrhoea (25%) vs. 53%, P = 0.005). Overall, the preventive administration of sucralfate appears to be an effective procedure to diminish the occurrence of severe oral and intestinal mucositis in patients treated by high dose chemotherapy alone or combined with TBI before bone marrow transplantation.