The role of H2-receptor antagonists in the prevention of NSAID-induced gastrointestinal damage

Clinical Dilemma Involving Treatments for Very Low-Birth-Weight Infants and the Potential Risk of Necrotizing Enterocolitis: A Narrative Literature Review

Necrotizing enterocolitis (NEC) is a critical gastrointestinal emergency with substantial morbidity and mortality risks, especially for very low-birth-weight (VLBW) infants, and unclear multifactorial pathophysiology. Whether common treatments for VLBW infants increase the NEC risk remains controversial. Indomethacin (utilized for patent ductus arteriosus) offers benefits but is concerning because of its vasoconstrictive impact on NEC susceptibility. Similarly, corticosteroids used to treat bronchopulmonary dysplasia may increase vulnerability to NEC by compromising immunity and altering the mesenteric blood flow. Histamine-2 receptor blockers (used to treat gastric bleeding) may inadvertently promote NEC by affecting bacterial colonization and translocation. Doxapram (used to treat apnea) poses a risk of gastrointestinal disturbance via gastric acid hypersecretion and circulatory changes. Glycerin enemas aid meconium evacuation but disrupt microbial equilibrium and trigger stress-related effects associated with the NEC risk. Prolonged antibiotic use may unintentionally increase the NEC risk. Blood transfusions for anemia can promote NEC via interactions between the immune response and ischemia-reperfusion injury. Probiotics for NEC prevention are associated with concerns regarding sepsis and bacteremia. Amid conflicting evidence, this review unveils NEC risk factors related to treatments for VLBW infants, offers a comprehensive overview of the current research, and guides personalized management strategies, thereby elucidating this clinical dilemma.

Pathogenic importance of pepsin in ischemia/reperfusion-induced gastric injury

We investigated the role of pepsin in the development of ischemia/reperfusion (I/R)-induced gastric lesions in rats. Under urethane anesthesia, the pylorus was ligated, the celiac artery was clamped, and 1 ml of HCl (50-150 mM) was instilled in the stomach. Then, reperfusion was established 15 min later by removing the clamp, and 2 h later the stomach was assessed for gross mucosal damage. Pepstatin (a specific pepsin inhibitor) or pepsin was given i.g. after the pylorus was ligated while cimetidine, omeprazole, or atropine was given s.c. 30 min before the ligation. I/R produced hemorrhagic gastric injury, with a concomitant increase in the amount of pepsin secreted, and the degree of both these responses was dependent on the concentration of HCl. The formation of lesions by IR in the presence of 100 mM HCl was significantly prevented by atropine or bilateral vagotomy, but neither omeprazole nor cimetidine had any effect. Intragastric administration of pepstatin dose-dependently reduced the severity of the I/R-induced gastric lesions, the effect being significant even at 0.1 mg/kg, while that of pepsin markedly aggravated these lesions. The increased pepsin output during I/R was associated with luminal acid loss and significantly inhibited by bilateral vagotomy or pretreatment with atropine but not cimetidine or omeprazole, while pepstatin significantly inhibited the pepsin activity. In conclusion, we suggest that pepsin plays a pivotal role in the pathogenesis of I/R-induced gastric lesions, and pepsin secretion is increased during I/R, the process being associated with acid back-diffusion and mediated through a vagal-cholinergic pathway.

Getting control of osteoarthritis pain. An update on treatment options

Osteoarthritis consists of a heterogeneous group of disorders that result in articular cartilage degeneration and is diagnosed on the basis of clinical findings. Pathogenesis involves an imbalance between the synthetic and degradative processes that occur in joints. Current interest in the role of cytokines and metalloproteinases may lead to improved treatment of osteoarthritis. For now, management consists of combinations of pharmacologic and nonpharmacologic therapies. A general pharmacologic approach is to begin with acetaminophen and add a low-dose NSAID, nonacetylated salicylate, selective COX-2 inhibitor, or topical capsaicin cream if needed. If pain persists, full-dose NSAID therapy, with the addition of a protective agent in patients at risk for gastrointestinal bleeding, or full-dose COX-2 inhibitor therapy may be tried. Joint injections, irrigation, or arthroscopy may be beneficial in some cases. In patients who continue to have pain and limited function despite these measures, surgical intervention should be considered.

Comparison of the gastrointestinal side effects of naproxen formulated as plain tablets, enteric-coated tablets, or enteric-coated granules in capsules

We studied the gastrointestinal side effects of three formulations of naproxen in 18 healthy male volunteers. In a Latin-square design crossover study, the subjects received 500 mg naproxen twice daily for 7 days as plain tablets, enteric-coated tablets, or enteric-coated granules in capsules. The 51Cr-EDTA absorption test was performed before and at the end of each drug period, to evaluate changes in the distal gut. The test dose was instilled distally in the duodenum to prevent lesions in the stomach from interfering with the evaluation. Upper endoscopy was performed at the same intervals, scoring changes in the middle and distal duodenum separately from findings in the stomach and duodenal bulb. The nature and severity of adverse effects were recorded for each treatment period. Non-parametric methods were used for statistical evaluation. All drugs induced a significant increase in 51Cr-EDTA absorption, but we did not detect any difference between the three formulations. All formulations were associated with a significant increase in all the endoscopic findings monitored. Enteric-coated tablets induced significantly less lesions than enteric-coated granules in the stomach and duodenal bulb, and an advantage over plain tablets was indicated. No difference was seen in the middle and distal duodenum. The proximal endoscopic scores were not correlated to those found in the middle and distal duodenum. Evaluation of the small and large bowel should probably be included in clinical studies of NSAIDs, but our findings suggest that the importance of transfer of mucosal lesions to the distal gut by enteric coating may have been overemphasized.