Clinical trial: endoscopic evaluation of naproxen etemesil, a naproxen prodrug, vs. naproxen - a proof-of-concept, randomized, double-blind, active-comparator study

Insights into Prospects of Novel NSAID Prodrugs in the Management of Gastrointestinal Toxicity: A Perspective Review

Non-steroidal anti-inflammatory drugs (NSAIDs) have a long history in the healthcare system due to their therapeutic potential. These NSAIDs cause ulcerogenicity, stomach pains, gastrointestinal hemorrhage, mucosa bleeding, and pancreatitis when used moderately and consistently. With researchers, managing the aforementioned adverse effects therapeutically is getting increasingly difficult. One method for creating NSAID moieties with low penetration as well as ulcerogenic properties is the prodrug technique. During the oral consumption of NSAID-prodrugs, ulcerations, intestinal hemorrhage, and mucosa hemorrhage have significantly decreased. Considering this background, this review focussed on NSAID prodrugs as well as their justifications, the pathogenesis of NSAIDs inducing gastrointestinal toxicity, and the role of different antioxidants and spacer groups. Prodrug moieties have more advantages over parent medicines concerning both solubility and lipophilicity. In general, NSAID-class prodrugs can successfully treat both acute and long-term inflammation and aches without causing ulcerotoxicity and related gastrointestinal side effects, which reduces their burden from the pharmacoeconomic perspective.

Frequency and Types of Pathological Upper Gastrointestinal Endoscopy Findings in Clinically Healthy Individuals

BACKGROUND AND OBJECTIVE

Beyond its application for diagnostics in patients, esophagogastroduodenoscopy (EGD) is used to assess gastrointestinal drug effects in clinical trials, where the interpretation of any pathological findings depends on the respective background variability. The objective of this analysis was to characterize the occurrence of pathological findings in the upper gastrointestinal tract in symptom-free healthy individuals.

METHODS

A baseline EGD was performed in clinically healthy individuals in three clinical trials aimed to assess gastrointestinal tolerability of drugs. Pathological findings were described by type (redness, erosion, ulcer or other), number, size and location, and by clinical relevance as assessed by the endoscopist. Characteristics of volunteers were tested as potential covariates.

RESULTS

A total of 294 EGDs were assessed. Characteristics of individuals were as follows: 257 (87.4%) males, age (mean ± SD) 32.0 ± 8.1 years, body weight 76.0 ± 10.6 kg, body mass index (BMI) 24.0 ± 2.5 kg/m2, 200 consumed alcohol, 250 (of 290 where this information was available) consumed caffeine and 39 (of 152) were smokers, 30 (of 151) tested positive for H. pylori. Any pathological finding was present in 79.6%. Clinically relevant findings occurred in 44.2%, mainly erosions (39.1%). Nine stomach ulcers were observed. Only age and BMI had a statistically significant relationship to overall pathological findings [age 3.4 years higher (p = 0.027), and BMI 1.6 kg/m2 higher (p < 0.001); for clinically relevant vs no findings].

CONCLUSION

Upper gastrointestinal tract mucosal lesions, including those assessed as clinically relevant, are frequent in clinically healthy individuals, impeding the assessment of causality for both disease and drug effects on gastrointestinal health.

Mechanisms, prevention and clinical implications of nonsteroidal anti-inflammatory drug-enteropathy

This article reviews the latest developments in understanding the pathogenesis, detection and treatment of small intestinal damage and bleeding caused by nonsteroidal anti-inflammatory drugs (NSAIDs). With improvements in the detection of NSAID-induced damage in the small intestine, it is now clear that this injury and the associated bleeding occurs more frequently than that occurring in the stomach and duodenum, and can also be regarded as more dangerous. However, there are no proven-effective therapies for NSAID-enteropathy, and detection remains a challenge, particularly because of the poor correlation between tissue injury and symptoms. Moreover, recent studies suggest that commonly used drugs for protecting the upper gastrointestinal tract (i.e., proton pump inhibitors) can significantly worsen NSAID-induced damage in the small intestine. The pathogenesis of NSAID-enteropathy is complex, but studies in animal models are shedding light on the key factors that contribute to ulceration and bleeding, and are providing clues to the development of effective therapies and prevention strategies. Novel NSAIDs that do not cause small intestinal damage in animal models offer hope for a solution to this serious adverse effect of one of the most widely used classes of drugs.

Preclinical evaluation of an inhibitor of cytosolic phospholipase A2α for the treatment of asthma

Asthma is a chronic inflammatory lung disease with considerable unmet medical needs for new and effective therapies. Cytosolic phospholipase A(2)α (cPLA(2)α) is the rate-limiting enzyme that is ultimately responsible for the production of eicosanoids implicated in the pathogenesis of asthma. We investigated a novel cPLA(2)α inhibitor, PF-5212372, to establish the potential of this drug as a treatment for asthma. PF-5212372 was a potent inhibitor of cPLA(2)α (7 nM) and was able to inhibit prostaglandin (PG)D(2) and cysteinyl leukotriene release from anti-IgE-stimulated human lung mast cells (0.29 and 0.45 nM, respectively). In a mixed human lung cell population, PF-5212372 was able to inhibit ionomycin-stimulated release of leukotriene B(4), thromboxane A(2), and PGD(2) (2.6, 2.6, and 4.0 nM, respectively) but was significantly less effective against PGE(2) release (>301 nM; p < 0.05). In an in vitro cell retention assay, PF-5212372 retained its potency up to 24 h after being washed off. In a sheep model of allergic inflammation, inhalation of PF-5212372 significantly inhibited late-phase bronchoconstriction (78% inhibition; p < 0.001) and airway hyper-responsiveness (94% inhibition; p < 0.001), and isolated sheep lung mast cell assays confirmed species translation via effective inhibition of PGD(2) release (0.78 nM). Finally, PF-5212372 was assessed for its ability to inhibit the contraction of human bronchi induced by AMP. PF5212372 significantly inhibited AMP-induced contraction of human bronchi (81% inhibition; p < 0.001); this finding, together with the ability of this drug to be effective in a wide range of preclinical asthma models, suggests that inhibition of cPLA(2)α with PF-5212372 may represent a new therapeutic option for the treatment of asthma.

Gastrointestinal tolerability of diclofenac epolamine topical patch 1.3%: a pooled analysis of 14 clinical studies

OBJECTIVE

The purpose of this investigation was to evaluate the gastrointestinal (GI) tolerability profile of diclofenac epolamine topical patch 1.3% (DETP) during short-term treatment in patients with mild-to-moderate pain.

DESIGN

Fourteen clinical trials of DETP were examined; 10 placebo-controlled studies were further integrated for analyses. All adverse event (AE) data were coded to the Medical Dictionary for Regulatory Activities.

OUTCOME MEASURES

Frequency of GI AEs was summarized by treatment, preferred term, sex, and age group.

RESULTS

The percentage of patients reporting GI AEs were similar between patients treated with the DETP and placebo, with only 3 of the 10 placebo-controlled trials reporting events in >2% of patients; there was no significant difference between DETP and placebo for any preferred GI term. The most common GI AE reported for both treatment groups was nausea (1.5% DETP, 1.1% placebo). There was no significant difference between treatment groups and sex in the number of reported events and no noted difference between age groups.

CONCLUSION

This study provides evidence that DETP is a topical nonsteroidal anti-inflammatory drug that is a well-tolerated treatment option, demonstrating a low incidence of GI AEs across 14 clinical trials, making it a possible alternative to short-term oral NSAIDs, which are commonly associated with GI complications.