Histamine H2-receptor antagonism improves conduit artery endothelial function and reduces plasma aldosterone level without lowering arterial blood pressure in angiotensin II-hypertensive mice.

Aldosterone through the mineralocorticoid receptor MR has detrimental effects on cardiovascular disease. It reduces the bioavailability of nitric oxide and impairs endothelium-dependent vasodilatation. In resistance arteries, aldosterone impairs the sensitivity of vascular smooth muscle cells to nitric oxide by promoting the local secretion of histamine which activates H2 receptors. The present experiments tested in vivo and ex vivo the hypothesis that systemic H2-receptor antagonism reduces arterial blood pressure and improves vasodilatation in angiotensin II-induced chronic hypertension. Hypertension was induced by intravenous infusion of angiotensin II (60 ng kg-1 min-1) in conscious, unrestrained mice infused concomitantly with the H2-receptor antagonist ranitidine (27.8 µg kg-1 min-1) or vehicle for 24 days. Heart rate and arterial blood pressure were recorded by indwelling arterial catheter. Resistance (mesenteric) and conductance (aortae) arteries were harvested for perfusion myography and isometric tension recordings by wire myography, respectively. Plasma was analyzed for aldosterone concentration. ANGII infusion resulted in elevated arterial blood pressure and while in vivo treatment with ranitidine reduced plasma aldosterone concentration, it did not reduce blood pressure. Ranitidine improved ex vivo endothelial function (acetylcholine 10-9 to 10-6 mol L-1) in mesenteric resistance arteries. This was abolished by ex vivo treatment with aldosterone (10-9 mol L-1, 1 h). In aortic segments, in vivo ranitidine treatment impaired relaxation. Activation of histamine H2 receptors promotes aldosterone secretion, does not affect arterial blood pressure, and protects endothelial function in conduit arteries but promotes endothelial dysfunction in resistance arteries during angiotensin II-mediated hypertension. Aldosterone contributes little to angiotensin II-induced hypertension in mice.

Development and validation of high-performance liquid chromatography-Orbitrap mass spectrometric method for quantification of NDMA in ranitidine drug products and evaluation of antioxidants as inhibitors of classical nitrosation reaction.

RATIONALE: N-Nitroso dimethylamine (NDMA) is a mutagenic impurity detected in several ranitidine products. The amino functional group of ranitidine is a risk factor for classical nitrosation-induced NDMA formation in ranitidine drug products during storage conditions. The United States Food and Drug Administration (US FDA) recommended the use of antioxidants to control NDMA in drug products. Considering the need for sensitive analytics, a liquid chromatography/high-resolution mass spectrometry (LC-HRMS) method was developed and validated to detect NDMA in this pilot study to demonstrate the antioxidants as inhibitors of nitrosation reactions. METHODS: The method, utilizing an EC-C18 column and tuned to atmospheric pressure chemical ionization/selected ion monitoring (APCI/SIM) mode, separated NDMA (m/z: 75.0553; tR: 3.71 min) and ranitidine (m/z: 315.1485; tR: 8.61 min). APCI mode exhibited four times higher sensitivity to NDMA than electrospray ionization (ESI) mode. Classical nitrosation of the dimethyl amino group of ranitidine was studied with sodium nitrite in solid pellets. Antioxidants (alpha-tocopherol, ascorbic acid, and trolox) were evaluated as NDMA attenuators in ranitidine pellets under vulnerable storage conditions. The developed method quantified NDMA levels in samples, extracted with methanol through vortex shaking for 45 min. RESULTS: The method achieved a limit of detection (LOD) and limit of quantitation (LOQ) of 0.01 and 0.05 ng/mL, respectively, with linearity within 1-5000 ng/mL (R1: 0.9995). It demonstrated good intra-day and inter-day precision (% RSD [relative standard deviation]: <2) and accuracy (96.83%-101.72%). Nitrosation of ranitidine induced by nitrite was significant (p < 0.001; R2 = 0.9579) at various sodium nitrite levels. All antioxidants efficiently attenuated NDMA formation during ranitidine nitrosation. Ascorbic acid exhibited the highest NDMA attenuation (96.98%), followed by trolox (90.58%). This study recommends 1% ascorbic acid and trolox as potent NDMA attenuators in ranitidine drug products. CONCLUSIONS: This study compared the effectiveness of antioxidants as NDMA attenuators in ranitidine under storage conditions susceptible to NDMA generation. The study concluded that ascorbic acid and trolox are potent inhibitors of NDMA formation and nitrosation attenuators in ranitidine drug products.

Targeting NF-κB/COX-2 signaling by soyasaponin I alleviates diclofenac-induced gastric ulceration in male albino rats.

Gastric ulceration is a prevalent worldwide clinical presentation due to altered gastric defense mechanisms. Nonsteroidal anti-inflammatory drugs are one of the common causes of gastric ulcers mediated by the release of inflammatory mediators. The study aimed to investigate the potential protective effect of soyasaponin I (soya) against diclofenac (DIC)-induced gastric ulcer in rats and to highlight the underlying mechanisms. The experiment was conducted on 40 male Wistar albino rats, equally distributed into five groups: control, DIC-induced ulcer (9 mg/kg/d, orally, twice daily for 3 days), ulcer/soya-, ulcer/ranitidine-, and ulcer/soya/selective nuclear factor kappa B inhibitor (JSH-23)-treated groups. The doses of soya, ranitidine, and JSH were 20, 25, and 5 mg/kg/d, respectively, given orally. Gastric specimens were prepared for gene and histological study and for biochemical analysis of gastric prostaglandin E2 (PGE2), oxidative markers, and inflammatory cytokines. The gastric samples were formalin-fixed, paraffin-embedded, and subjected to hematoxylin and eosin (H&E), PAS staining, and immunohistochemical assay for identification of nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX-2), and proliferation marker (Ki67) expressions. The findings revealed decreased gastric PGE2 and altered inflammatory and oxidative markers in the ulcer model group. The H&E staining showed mucosal injury characterized by mucosal surface defects and inflammatory cell infiltrations. The polymerase chain reaction (PCR) and immunohistochemistry demonstrated an upregulation of NF-κB and COX-2 expression at gene/protein levels; meanwhile, Ki67 downregulation. The soya-treated group showed maintained biochemical, histological, and PCR findings comparable to the ranitidine-treated group. The JSH-23-treated group still showed partial gastric protection with biochemical and immunohistochemical changes. Soyasaponin I ameliorated DIC-induced gastric ulcers by targeting the COX-2 activity through modulation of NF-κB signaling.

Rapid Structure Determination of Ranitidine Hydrochloride API in Two Crystal Forms Using Microcrystal Electron Diffraction.

The solid-state properties of drug candidates play a crucial role in their selection. Quality control of active pharmaceutical ingredients (APIs) based on their structural information involves ensuring a consistent crystal form and controlling water and residual solvent contents. However, traditional crystallographic techniques have limitations and require high-quality single crystals for structural analysis. Microcrystal electron diffraction (microED) overcomes these challenges by analyzing difficult-to-crystallize or small-quantity samples, making it valuable for efficient drug development. In this study, microED analysis was able to rapidly determine the configuration of two crystal forms (Forms 1, 2) of the API ranitidine hydrochloride. The structures obtained with microED are consistent with previous structures determined by X-ray diffraction, indicating microED is a useful tool for rapidly analyzing molecular structures in drug development and materials science research.

In Silico Prediction of N-Nitrosamine Formation Pathways of Pharmaceutical Products.

The recent discovery of N-nitrosodimethylamine (NDMA), a mutagenic N-nitrosamine, in pharmaceuticals has adversely impacted the global supply of relevant pharmaceutical products. Contamination by N-nitrosamines diverts resources and time from research and development or pharmaceutical production, representing a bottleneck in drug development. Therefore, predicting the risk of N-nitrosamine contamination is an important step in preventing pharmaceutical contamination by DNA-reactive impurities for the production of high-quality pharmaceuticals. In this study, we first predicted the degradation pathways and impurities of model pharmaceuticals, namely gliclazide and indapamide, in silico using an expert-knowledge software. Second, we verified the prediction results with a demonstration test, which confirmed that N-nitrosamines formed from the degradation of gliclazide and indapamide in the presence of hydrogen peroxide, especially under alkaline conditions. Furthermore, the pathways by which degradation products formed were determined using ranitidine, a compound previously demonstrated to generate NDMA. The prediction indicated that a ranitidine-related compound served as a potential source of nitroso groups for NDMA formation. In silico software is expected to be useful for developing methods to assess the risk of N-nitrosamine formation from pharmaceuticals.

Major Shifts in Acid Suppression Drug Utilization After the 2019 Ranitidine Recalls in Canada and United States.

BACKGROUND: Drug shortages are a complex global challenge, and few studies have analyzed quantitative data on their impacts. In September 2019, detection of a nitrosamine impurity in ranitidine led to recalls and shortages. AIMS: We investigated the extent of the ranitidine shortage and its impacts on acid suppression drug utilization in Canada and the United States (US). METHODS: We conducted an interrupted time series analysis of acid suppression drug purchases in Canada and the US from 2016 through 2021 using IQVIA's MIDAS database. We used autoregressive integrated moving average models to determine the impact of the shortage on purchasing rates for ranitidine, other histamine-2 receptor antagonists (H2RAs), and proton pump inhibitors (PPIs). RESULTS: Prior to the recalls, 20,439,915 ranitidine units were purchased monthly in Canada and 189,038,496 in the US on average. After the recalls started in September 2019, purchasing rates decreased for ranitidine (Canada p = 0.0048, US p < 0.0001) and increased for non-ranitidine H2RAs (Canada p = 0.0192, US p = 0.0534). One month into the recalls, purchasing rates dropped by 99% (Canada) and 53% (US) for ranitidine and increased by 128.3% (Canada) and 37.3% (US) for non-ranitidine H2RAs. PPI purchasing rates did not change significantly in either country. CONCLUSIONS: The ranitidine shortage led to immediate and sustained shifts in H2RA utilization in both countries, potentially affecting hundreds of thousands of patients. Our results emphasize the need for future studies of the clinical and financial implications of the shortage, and the importance of ongoing work to mitigate and prevent drug shortages.

Pharmacological treatment of gastro-oesophageal reflux in children.

BACKGROUND: Gastro-oesophageal reflux (GOR) is characterised by the regurgitation of gastric contents into the oesophagus. GOR is a common presentation in infancy, both in primary and secondary care, affecting approximately 50% of infants under three months old. The natural history of GOR in infancy is generally of a self-limiting condition that improves with age, but older children and children with co-existing medical conditions can have more protracted symptoms. The distinction between gastro-oesophageal reflux disease (GORD) and GOR is debated. Current National Institute of Health and Care Excellence (NICE) guidelines define GORD as GOR causing symptoms severe enough to merit treatment. This is an update of a review first published in 2014. OBJECTIVES: To assess the effects of pharmacological treatments for GOR in infants and children. SEARCH METHODS: For this update, we searched CENTRAL, MEDLINE, Embase, and Web of Science up to 17 September 2022. We also searched for ongoing trials in clinical trials registries, contacted experts in the field, and searched the reference lists of trials and reviews for any additional trials. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that compared any currently-available pharmacological treatment for GOR in children with placebo or another medication. We excluded studies assessing dietary management of GORD and studies of thickened feeds. We included studies in infants and children up to 16 years old. DATA COLLECTION AND ANALYSIS: We used standard methodology expected by Cochrane. MAIN RESULTS: We included 36 RCTs involving 2251 children and infants. We were able to extract summary data from 14 RCTs; the remaining trials had insufficient data for extraction. We were unable to pool results in a meta-analysis due to methodological differences in the included studies (including heterogeneous outcomes, study populations, and study design). We present the results in two groups by age: infants up to 12 months old, and children aged 12 months to 16 years old. Infants Omeprazole versus placebo: there is no clear effect on symptoms from omeprazole. One study (30 infants; very low-certainty evidence) showed cry/fuss time in infants aged three to 12 months had altered from 246 ± 105 minutes/day at baseline (mean +/- standard deviation (SD)) to 191 ± 120 minutes/day in the omeprazole group and from 287 ± 132 minutes/day to 201 ± 100 minutes/day in the placebo group (mean difference (MD) 10 minutes/day lower (95% confidence interval (CI) -89.1 to 69.1)). The reflux index changed in the omeprazole group from 9.9 ± 5.8% in 24 hours to 1.0 ± 1.3% and in the placebo group from 7.2 ± 6.0% to 5.3 ± 4.9% in 24 hours (MD 7% lower, 95% CI -4.7 to -9.3). Omeprazole versus ranitidine: one study (76 infants; very low-certainty evidence) showed omeprazole may or may not provide symptomatic benefit equivalent to ranitidine. Symptom scores in the omeprazole group changed from 51.9 ± 5.4 to 2.4 ± 1.2, and in the ranitidine group from 47 ± 5.6 to 2.5 ± 0.6 after two weeks: MD -4.97 (95% CI -7.33 to -2.61). Esomeprazole versus placebo: esomeprazole appeared to show no additional reduction in the number of GORD symptoms compared to placebo (1 study, 52 neonates; very low-certainty evidence): both the esomeprazole group (184.7 ± 78.5 to 156.7 ± 75.1) and placebo group (183.1 ± 77.5 to 158.3 ± 75.9) improved: MD -3.2 (95% CI -4.6 to -1.8). Children Proton pump inhibitors (PPIs) at different doses may provide little to no symptomatic and endoscopic benefit. Rabeprazole given at different doses (0.5 mg/kg and 1 mg/kg) may provide similar symptom improvement (127 children in total; very low-certainty evidence). In the lower-dose group (0.5 mg/kg), symptom scores improved in both a low-weight group of children (< 15 kg) (mean -10.6 ± SD 11.13) and a high-weight group of children (> 15 kg) (mean -13.6 ± 13.1). In the higher-dose groups (1 mg/kg), scores improved in the low-weight (-9 ± 11.2) and higher-weight groups (-8.3 ± 9.2). For the higher-weight group, symptom score mean difference between the two different dosing regimens was 2.3 (95% CI -2 to 6.6), and for the lower-weight group, symptom score MD was 4.6 (95% CI -2.9 to 12). Pantoprazole: pantoprazole may or may not improve symptom scores at 0.3 mg/kg, 0.6 mg/kg, and 1.2 mg/kg pantoprazole in children aged one to five years by week eight, with no difference between 0.3 mg/kg and 1.2 mg/kg dosing (0.3 mg/kg mean -2.4 ± 1.7; 1.2 mg/kg -1.7 ± 1.2: MD 0.7 (95% CI -0.4 to 1.8)) (one study, 60 children; very low-certainty evidence). There were insufficient summary data to assess other medications. AUTHORS' CONCLUSIONS: There is very low-certainty evidence about symptom improvements and changes in pH indices for infants. There are no summary data for endoscopic changes. Medications may or may not provide a benefit (based on very low-certainty evidence) for infants whose symptoms remain bothersome, despite nonmedical interventions or parental reassurance. If a medication is required, there is no clear evidence based on summary data for omeprazole, esomeprazole (in neonates), H2antagonists, and alginates for symptom improvements (very low-certainty evidence). Further studies with longer follow-up are needed. In older children with GORD, in studies with summary data extracted, there is very low-certainty evidence that PPIs (rabeprazole and pantoprazole) may or may not improve GORD outcomes. No robust data exist for other medications. Further RCT evidence is required in all areas, including subgroups (preterm babies and children with neurodisabilities).

Advanced Solid-State NMR Analysis of Two Crystal Forms of Ranitidine Hydrochloride: Detection of 1H-14N Intra-/Intermolecular Correlations.

Understanding the characteristics of crystal polymorphism of active pharmaceutical ingredients and analyzing them with high sensitivity is important for quality of drug products, appropriate characterization strategies, and appropriate screening and selection processes. However, there are few methods to measure intra- and intermolecular correlations in crystals other than X-ray crystallography, for which it is sometimes difficult to obtain suitable single crystals. Recently, solid-state NMR has been recognized as a straightforward method for measuring molecular correlations. In this study, we selected ranitidine hydrochloride, which is known to exist in two forms, 1 and 2, as the model drug and investigated each form using solid-state NMR. In conducting the analysis, rotating the sample tube, which had a 1-mm inner diameter, increased the solid-state NMR resolution at 70 kHz. The 1H-14N dipolar-based heteronuclear multiple quantum coherence (D-HMQC) analysis revealed the intermolecular correlation of Form 1 between the N atom of the nitro group and a proton of the furan moiety, which were closer than those of the intramolecular correlation reported using single X-ray crystal analysis. Thus, 1H-14N D-HMQC analysis could be useful for characterizing intermolecular interaction in ranitidine hydrochloride crystals. In addition, we reassigned the 13C solid-state NMR signals of ranitidine hydrochloride according to the liquid-state and multiple solid-state NMR experiments.

Silver nanoparticles synthesized from Quercus brantii ameliorated ethanol-induced gastric ulcers in rats by decreasing oxidative stress and improving antioxidant systems.

Gastric ulcers are caused by an imbalance between aggressive and defensive factors. The green synthesis of silver nanoparticles is becoming a new and promising method in the treatment of gastrointestinal ulcers. This study was conducted to investigate the protective and antioxidant effects of silver nanoparticles synthesized from Quercus brantii extract (NSQBE) on gastric damage induced by alcohol in rats. In this study, silver nanoparticles were produced by the green synthesis method using oak extract. The structure and morphology of nanoparticles were confirmed by various techniques such as UV-Vis spectroscopy, fourier transforms infrared spectrometer (FTIR), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), and dynamic light scattering )DLS(. For the animal studies, 30 male Wistar rats weighing 200 ± 20 g were randomly selected and divided into five groups (the normal, ethanolic, NSQBE treatment (received doses of 20 and 5 mg/kg), and standard (received a dose of 50 mg/kg of ranitidine) groups. After the rats were euthanized, their stomach was removed. A part of the stomach tissue of rats was used for histopathological studies, and the other part was used to study biochemical parameters such as the level of reactive oxygen species (ROS), protein carbonyl oxidation (PCO), malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD) and reduced glutathione (GSH) as well as nitric oxide (NO). Our results showed that in the ethanol group, the levels of ROS, MDA, PCO, and serum NO were higher than in the normal group. In addition, reduced GSH, CAT, SOD, tissue NO, gastric mucus, and antioxidant potential were decreased. In rats pretreated with NSQBE and ranitidine, the levels of ROS, MDA, PCO, and serum NO decreased, and the levels of GSH, CAT, SOD, tissue NO, gastric mucus, and antioxidant potential were increased in comparison to the ethanol group. The results of this study showed that silver nanoparticles synthesized using Quercus brantii are a promising approach for the treatment of gastric ulcers.

Simultaneous interaction, degradation, and kinetic study of sparfloxacin with H2 receptor antagonist.

Sparfloxacin is a quinolone carboxylic acid derivative that shows activity as an antimicrobial agent, against a wide range of Gram-negative and Gram-positive organisms. It is clinically useful for the treatment of urinary tract infections, respiratory tract infections and gynecological infections. In this study in vitro drug-drug interaction of sparfloxacin has been carried out with famotidine and ranitidine. For these studies a two-component spectrophotometric process has been developed for sparfloxacin assay in the presence of famotidine or ranitidine. The reproducibility of the method is within ±5%. The technique has been applied to the development of sparfloxacin in methanol. The interaction studies of sparfloxacin with ranitidine and famotidine were carried out in methanol and methanol: Water mixtures (30:70, v/v; 50:50, v/v) and the kinetics of sparfloxacin degradation were evaluated in the presence and absence of famotidine and ranitidine. The decrease in the rate of degradation of sparfloxacin in the presence of famotidine or ranitidine, compared to that of sparfloxacin alone, indicated the possibility of interaction between the sparfloxacin and famotidine or ranitidine. The Thin layer chromatography (TLC) of the degraded solution showed the presence of a degradation product of sparfloxacin. The studies show that complexation with famotidine or ranitidine may affect the bioavailability of sparfloxacin.

Optimization of ranitidine hydrochloride based on stability performance in directly compressible immediate and sustained release formulations.

Ranitidine hydrochloride (RTD), a moisture-sensitive drug, has issues of stability during shelf life especially when formulated through wet granulation method. In current study, RTD was blended with non-hygroscopic excipient like ethyl cellulose and compressed using direct compression method. The physical and physicochemical characteristics were evaluated including hardness, thickness, diameter, friability, weight variation, disintegration, dissolution and accelerated stability study to optimize findings. Subsequently, the optimized formulation was characterized for Fourier Transform Infrared (FTIR) analysis and in vitro drug release kinetics. The physical characterization was unaffected by polymer variation while the friability and weight variation were within the USP limits. In vitro drug release depicted that the release rate was sustained by increasing the amount of ethyl cellulose, with a 10% increase of ethyl cellulose 99.09% drug was released. FTIR analysis exhibited no interaction among the ingredients of the optimized formulation (E2). The optimized formulation followed Hixson-Crowell release kinetics. Formulation A5 displayed immediate release characters as plain uncoated formulation. Accelerated studies showed no significant change in the drug content. The RTD was successfully sustained to be released up to 6 h and accelerated stability showed that the optimized formulation (E2) containing 4% starch 1500 and 10% of ethyl cellulose, respectively, was stable up to 6 months.

MELANOMA AND DYSPLASTIC NEVI DEVELOPMENT AFTER RANITIDINE/RILMENIDINE/МOXONIDINE, LERCANIDIPINE, ROSUVASTATIN AND VERAPAMIL/TRANDOLAPRIL - NEW DATA/CASE SERIES. THE POTENTIAL ROLE OF NITROSAMINE/NDSRIS CONTAMINATION IN POLYMEDICATION AS SUBSTANTIAL SKIN CANCER TRIGGERING FACTOR.

The idea of drug-induced/exogenic Nitrosogenesis is driven by the possibility of prolonged exposure of the human body to the influence of nitrosamines within the drug intake - substances or contaminants that have been proven to be carcinogenic or mutagenic one.Until recently, there was a complete lack of data in the scientific literature on the relationship between cancer, polymedication and polycontamination with nitrosamines. In the last decade, melanoma has been described repeatedly in the medical literature as a possible side-effect within the intake of possibly with nitrosamines contaminated medications such as: Valsartan, Hydrochlorothiazide, Amlodipine, Nebivolol, Bisoprolol and Perindopril. However, the contribution of the currently presented new data (5 new patients) is also due to the establishment of the possible pathogenetic role (with respect to melanoma) of several completely new drugs, previously unknown to the scientific community (potentially/actually contaminated with carcinogens/nitrosamines), such as: Ranitidine, Rosuvastatin, Lercanidipine, Rilmenidine, Trandolapril, Moxonidine and Verapamil.The leading and connecting link in shared new and old drug combinations of heterogeneous drug classes (polymedication) and melanoma development and progression remains again one and the same: the possible availability of nitroso component in the frame of exogenous nitrosogenesis according to the official FDA lists of 2023.The number of drugs shared as contaminated with nitrosamines after whose intake melanomas occur is increasing. Nitrosogenesis remains a new beginning, a new understanding and new interpretation of the carcinogenesis concerning melanoma, but probably also of cancer in general. Its further elucidation looks more than promising and is yet to come. More than worrying at the moment remains the fact that the scientific community has to clarify if: 1) peak concentrations of nitrosamines or NDSRIs within the framework of monomedication or 2) normal concentrations within the polymedication (catalogued in the list of FDA/ 2023 as potentially contaminated with hypothetical carcinogens), could hide relatively short-term risk of the development of real tumors: cutaneous melanomas and/or their precursor lesions. The validation of the concept of Nitrosogenesis and its relationship to Сarcinogenesis, is achieved in practice on the basis of the following facts: that it is the occurrence of the same monomorphic clinical pattern (melanoma/dysplastic nevi), developing after the intake of drugs with different mechanism of action, contaminated with nitrosamines/NDSRIs. The unifying link between the intake of certain drugs and the development of certain tumours remains the presence of nitrosamines. Ingredients that are present in drug preparations, identified as availability and as carcinogenic potency, but not yet reflected in packaging or prescriptions. The question remains: why?

MULTIPLE BCCS AND DYSPLASTIC NEVI AFTER ACE INHIBITORS (ENALAPRIL/PERINDOPRIL): THE ROLE OF NITROSAMINE CONTAMINATION/AVAILABILITY AS SUBSTANTIAL SKIN CANCER TRIGGERING FACTOR.

Nitrosamines as contaminants in a wide variety of drugs are also found to be one of the most likely causes of skin cancer. A detailed analysis of this contamination could in the near future solve to a large extent the puzzle of carcinogenesis concerning the keratinocytic forms of cancer and melanoma. But also, probably cancer in general. Over 80% of skin cancer is due to acquired mutations, and nitrosamines, which are contained as contamination in certain batches of the most commonly distributed drugs worldwide (such as sartans, ACE inhibitors, ranitidine, metformin, hydrochlorothiazide, rifampicin, and a number of others.) are considered among the most powerful external mutagens, carcinogens. Carcinogens that until 2021 were not supposed to be present in medicines and carcinogens for which it was subsequently decided to create a regulatory regime for permissible availability. Regardless of whether these contaminants are applied within the so-called daily acceptable intake dose or many times above it, the problem with the availability of nitrosamines continues to be present. It is also caused by the lack of reflection of the concentration of the corresponding nitrosamine in a certain drug. Thus, it is impossible to calculate the ˝permissible daily intake of the total number of mutagens and their concentration based on polymedication˝. In practice, drug manufacturers distribute nitrosamines in parallel with drugs, although they are not listed as a component of the product but are identified and allowed as contamination or substances with permissible availability by the EMA/FDA. From another point of view, the fact that is not commented on is also of interest, namely that not all batches are affected by this contamination. This suggests that the contamination may have been controlled, since in a manufacturing error the contamination should be widespread. The registration of the potential contamination of a heterogeneous type of medicinal products on the European market to the executive agencies for drug control in certain geographical areas has remained for years without any answer and opens a number of questions. The problem with ACE inhibitors is similar to that with sartans, hydrochlorothiazide, metformin, and ranitidine. The ˝special impression˝ of the clinicians is determined by the fact that the patterns of manifestation of the skin tumors during the administration of a heterogeneous class of medications are similar to completely identical. From this it could be concluded that the unifying factor between the pattern of occurrence could not be based on the action of the main substance of each drug class, since it remains to be radically different. The unifying link remains the sole and only contamination or the permissible already availability of a new ingredient known as nitrosamines. We present cases of multiple basal cell carcinomas and dysplastic nevi following enalapril and perindopril administration. The role of potential contamination of ACE inhibitors with nitrosamines for the development of skin cancer is discussed.

In Esophageal Squamous Cells From Eosinophilic Esophagitis Patients, Th2 Cytokines Increase Eotaxin-3 Secretion Through Effects on Intracellular Calcium and a Non-Gastric Proton Pump.

BACKGROUND & AIMS: In upper airway cells, T helper 2 cytokines that signal through interleukin-4 (IL-4) receptor-α have been shown to stimulate eotaxin-3 secretion via a nongastric proton pump (ngH+,K+ATPase). To seek novel targets for eosinophilic esophagitis (EoE) treatments, we evaluated ngH+,K+ATPase expression in EoE squamous cells, and explored molecular pathways involved in eotaxin-3 secretion by IL-4 receptor-α signaling. METHODS: ngH+,K+ATPase expression in EoE cells was evaluated by quantitative real-time polymerase chain reaction and Western blotting. IL-4-stimulated eotaxin-3 secretion was measured by enzyme-linked immunosorbent assay after treatment with omeprazole, SCH 28080 (potassium-competitive acid blocker), ethylene glycol-bis(ß-aminoethyl)-N,N,N',N'-tetraacetoxymethyl ester (calcium chelator), 2-aminoethoxydiphenyl borate (inhibitor of endoplasmic reticulum calcium release), verapamil, and diltiazem (L-type calcium channel inhibitors). Intracellular calcium transients were measured by Fluo-4 fluorescence. Key experiments were confirmed in EoE primary cells and in RNA sequencing datasets from mucosal biopsies of patients with EoE and controls. RESULTS: EoE cells expressed ngH+,K+ATPase messenger RNA and protein. Omeprazole and SCH 28080 decreased IL-4-stimulated eotaxin-3 secretion. IL-4 increased intracellular calcium transients, and IL-4-stimulated eotaxin-3 secretion was blocked by ethylene glycol-bis(ß-aminoethyl)-N,N,N',N'-tetraacetoxymethyl ester, 2-aminoethoxydiphenyl borate, verapamil, and diltiazem. The combination of omeprazole and verapamil suppressed IL-4-stimulated eotaxin-3 secretion more than either agent alone. EoE biopsies expressed higher ngH+,K+ATPase and exhibited more calcium signaling than controls. CONCLUSIONS: EoE cells express a nongastric proton pump that mediates T helper 2 cytokine-stimulated eotaxin-3 secretion. IL-4 induces calcium release from the endoplasmic reticulum and calcium entry via L-type calcium channels, increasing intracellular calcium that contributes to eotaxin-3 secretion by EoE cells. L-type calcium channel inhibitors block T helper 2 cytokine-stimulated eotaxin-3 secretion, suggesting a potential role for these agents in EoE treatment.

Using in vitro ADME data for lead compound selection: An emphasis on PAMPA pH 5 permeability and oral bioavailability.

Membrane permeability plays an important role in oral drug absorption. Caco-2 and Madin-Darby Canine Kidney (MDCK) cell culture systems have been widely used for assessing intestinal permeability. Since most drugs are absorbed passively, Parallel Artificial Membrane Permeability Assay (PAMPA) has gained popularity as a low-cost and high-throughput method in early drug discovery when compared to high-cost, labor intensive cell-based assays. At the National Center for Advancing Translational Sciences (NCATS), PAMPA pH 5 is employed as one of the Tier I absorption, distribution, metabolism, and elimination (ADME) assays. In this study, we have developed a quantitative structure activity relationship (QSAR) model using our ∼6500 compound PAMPA pH 5 permeability dataset. Along with ensemble decision tree-based methods such as Random Forest and eXtreme Gradient Boosting, we employed deep neural network and a graph convolutional neural network to model PAMPA pH 5 permeability. The classification models trained on a balanced training set provided accuracies ranging from 71% to 78% on the external set. Of the four classifiers, the graph convolutional neural network that directly operates on molecular graphs offered the best classification performance. Additionally, an ∼85% correlation was obtained between PAMPA pH 5 permeability and in vivo oral bioavailability in mice and rats. These results suggest that data from this assay (experimental or predicted) can be used to rank-order compounds for preclinical in vivo testing with a high degree of confidence, reducing cost and attrition as well as accelerating the drug discovery process. Additionally, experimental data for 486 compounds (PubChem AID: 1645871) and the best models have been made publicly available (https://opendata.ncats.nih.gov/adme/).

Selective histamine H2 receptor agonists alleviate blood-brain barrier disruption by promoting the expression of vascular protective factors following traumatic brain injury in mice.

Histamine is a major neurotransmitter and alleviates neuronal damage after ischemic injury via H2 receptors. Herein, we investigated the effects of H2 receptor agonists on the blood-brain barrier (BBB) disruption after traumatic brain injury (TBI). Male ddY mice were used to generate the TBI model, in which a fluid percussion injury (FPI) was induced by a hydraulic impact. The BBB disruption was evaluated using Evans blue extravasation. H2 receptor agonists, amthamine and dimaprit, were administered into the lateral cerebroventricle (i.c.v.) or tail vein (i.v.) from 3 hours to 3 days after FPI. The i.c.v. or i.v. administration of amthamine and dimaprit reduced FPI-induced Evans blue extravasation and promoted mRNA expression of vascular protective factors, including angiopoietin-1 and sonic hedgehog. The co-administration of ranitidine, a H2 receptor antagonist, inhibited these effects. Expression of the H2 receptor was observed in astrocytes and brain microvascular endothelial cells (BMECs) in the injured cortex. Treatment with amthamine and dimaprit promoted mRNA expression of vascular protective factors in astrocytes and BMECs. These results suggest that H2 receptor agonists alleviate TBI-induced BBB disruption by increasing the expression of vascular protective factors in astrocytes and BMECs.

Ranitidine Use and Gastric Cancer Among Persons with Helicobacter pylori.

BACKGROUND: The Food and Drug Administration requested withdrawal of ranitidine formulations, due to a potentially carcinogenic contaminant, N-nitrosodimethylamine. AIMS: We evaluate whether ranitidine use is associated with gastric cancer. METHODS: This is a retrospective multicenter, nationwide cohort study within the Veterans Health Administration, among patients with Helicobacter pylori (HP) prescribed long-term acid suppression with either: (1) ranitidine, (2) other histamine type 2 receptor blocker (H2RB), or (3) proton pump inhibitor (PPI)) between May 1, 1998, and December 31, 2018. Covariates included race, ethnicity, smoking, age, HP treatment, HP eradication. Primary outcome was non-proximal gastric adenocarcinomas, using multivariable Cox proportional hazards analysis. RESULTS: We identified 279,505 patients with HP prescribed long-term acid suppression (median 53.4 years; 92.9% male). Compared to ranitidine, non-ranitidine H2RB users were more likely to develop cancer (HR 1.83, 95%CI 1.36-2.48); PPI users had no significant difference in future cancer risk (HR 0.92, 95% CI 0.82-1.04), p < 0.001. Demographics associated with future cancer included increasing age (HR 1.18, 95% CI 1.15-1.20, p < 0.001), Hispanic/Latino ethnicity (HR 1.46, 95% CI 1.21-1.75, p < 0.001), Black race (HR 1.89, 95% CI 1.68-2.14) or Asian race (HR 2.03, 95% CI 1.17-3.52), p < 0.001, and gender (female gender HR 0.64, 95% CI 0.48-0.85, p = 0.02). Smoking was associated with future cancer (HR 1.38, 95% CI 1.23-1.54, p < 0.001). Secondary analysis demonstrated decreased cancer risk in those with confirmed HP eradication (HR 0.24, 95% CI 0.14-0.40). No association between ranitidine and increased gastric cancer was found. CONCLUSION: There is no demonstrable association between ranitidine use and future gastric cancer among individuals with HP on long-term acid suppression.

Pharmacological interventions for prevention of weight gain in people with schizophrenia.

BACKGROUND: Antipsychotic-induced weight gain is an extremely common problem in people with schizophrenia and is associated with increased morbidity and mortality. Adjunctive pharmacological interventions may be necessary to help manage antipsychotic-induced weight gain. This review splits and updates a previous Cochrane Review that focused on both pharmacological and behavioural approaches to this problem. OBJECTIVES: To determine the effectiveness of pharmacological interventions for preventing antipsychotic-induced weight gain in people with schizophrenia. SEARCH METHODS: The Cochrane Schizophrenia Information Specialist searched Cochrane Schizophrenia's Register of Trials on 10 February 2021. There are no language, date, document type, or publication status limitations for inclusion of records in the register. SELECTION CRITERIA: We included all randomised controlled trials (RCTs) that examined any adjunctive pharmacological intervention for preventing weight gain in people with schizophrenia or schizophrenia-like illnesses who use antipsychotic medications. DATA COLLECTION AND ANALYSIS: At least two review authors independently extracted data and assessed the quality of included studies. For continuous outcomes, we combined mean differences (MD) in endpoint and change data in the analysis. For dichotomous outcomes, we calculated risk ratios (RR). We assessed risk of bias for included studies and used GRADE to judge certainty of evidence and create summary of findings tables. The primary outcomes for this review were clinically important change in weight, clinically important change in body mass index (BMI), leaving the study early, compliance with treatment, and frequency of nausea. The included studies rarely reported these outcomes, so, post hoc, we added two new outcomes, average endpoint/change in weight and average endpoint/change in BMI. MAIN RESULTS: Seventeen RCTs, with a total of 1388 participants, met the inclusion criteria for the review. Five studies investigated metformin, three topiramate, three H2 antagonists, three monoamine modulators, and one each investigated monoamine modulators plus betahistine, melatonin and samidorphan. The comparator in all studies was placebo or no treatment (i.e. standard care alone). We synthesised all studies in a quantitative meta-analysis. Most studies inadequately reported their methods of allocation concealment and blinding of participants and personnel. The resulting risk of bias and often small sample sizes limited the overall certainty of the evidence. Only one reboxetine study reported the primary outcome, number of participants with clinically important change in weight. Fewer people in the treatment condition experienced weight gains of more than 5% and more than 7% of their bodyweight than those in the placebo group (> 5% weight gain RR 0.27, 95% confidence interval (CI) 0.11 to 0.65; 1 study, 43 participants; > 7% weight gain RR 0.24, 95% CI 0.07 to 0.83; 1 study, 43 participants; very low-certainty evidence). No studies reported the primary outcomes, 'clinically important change in BMI', or 'compliance with treatment'. However, several studies reported 'average endpoint/change in body weight' or 'average endpoint/change in BMI'. Metformin may be effective in preventing weight gain (MD -4.03 kg, 95% CI -5.78 to -2.28; 4 studies, 131 participants; low-certainty evidence); and BMI increase (MD -1.63 kg/m2, 95% CI -2.96 to -0.29; 5 studies, 227 participants; low-certainty evidence). Other agents that may be slightly effective in preventing weight gain include H2 antagonists such as nizatidine, famotidine and ranitidine (MD -1.32 kg, 95% CI -2.09 to -0.56; 3 studies, 248 participants; low-certainty evidence) and monoamine modulators such as reboxetine and fluoxetine (weight: MD -1.89 kg, 95% CI -3.31 to -0.47; 3 studies, 103 participants; low-certainty evidence; BMI: MD -0.66 kg/m2, 95% CI -1.05 to -0.26; 3 studies, 103 participants; low-certainty evidence). Topiramate did not appear effective in preventing weight gain (MD -4.82 kg, 95% CI -9.99 to 0.35; 3 studies, 168 participants; very low-certainty evidence). For all agents, there was no difference between groups in terms of individuals leaving the study or reports of nausea. However, the results of these outcomes are uncertain given the very low-certainty evidence. AUTHORS' CONCLUSIONS: There is low-certainty evidence to suggest that metformin may be effective in preventing weight gain. Interpretation of this result and those for other agents, is limited by the small number of studies, small sample size, and short study duration. In future, we need studies that are adequately powered and with longer treatment durations to further evaluate the efficacy and safety of interventions for managing weight gain.

Conservative therapy is associated with worse clinical features and biochemical derangements than renal replacement therapy: a retrospective study in Kumasi, Ghana.

BACKGROUND: The incidence of end stage kidney disease (ESKD) is increasing in Ghana as with the rest of the world. This study compared the sociodemographic, diagnostic characteristics (clinical, biochemical and imaging) and clinical outcomes of ESKD patients who chose either renal replacement therapy (RRT) or conservative therapy as well as the factors that influenced their choice. METHODS: We retrospectively reviewed the records of 382 ESKD patient from 2006 to 2018. The data was collected from the Nephrology Clinic at the Komfo Anokye Teaching Hospital (KATH). Sociodemographic, diagnostic (clinical, biochemical and imaging) and therapeutic data were obtained, organized and analyzed with Statistical Package for the Social Sciences (SPSS). RESULTS: Of the 382 patients, 321 had conservative therapy whiles 61 had renal replacement therapy. The mean age of participants was 47.71 ± 16.10 years. Bipedal swelling (16.8%), fatigue (10.4%) and facial swelling (9.2%) were the major clinical features. Chronic glomerulonephritis (31.4%), hypertension (30.3%) and diabetes mellitus nephropathy (28.2%) were the most frequent predisposing conditions. Nifedipine (82.0%), bisoprolol (32.8%), aspirin (19.7%), ranitidine (26.2%), metformin (13.1%) and lasix (78.7%) were commonly used by the RRT patients than their conservative therapy counterparts. Compared to their RRT counterparts, patients on conservative therapy were more on irbesartan/lisinopril (57.9%) and sodium hydro carbonate (NaHCO3) (52.0%). Diastolic blood pressure (DBP) (p = 0.047), uremic gastritis (p = 0.007), anaemia, uraemia, haematuria and hyperkalaemia (p < 0.001) were more common in conservative therapy patients than RRT patients with RRT patients showing better corticomedullary differentiation (38.1% vs. 27.7%, p < 0.001) and normal echotexture (15.0% vs. 11.6%, p = 0.005). Age, gender, occupation and duration of illness were significantly associated with the decision to opt for conservative therapy. CONCLUSION: Patients on conservative therapy have worse clinical outcomes than their RRT counterparts. Early referrals to nephrologist as well as subsidized RRT should be targeted.

Ranitidine decreases human sperm motility and vitality and increases the activity of seminal creatine kinase.

Ranitidine (brand name: Zantac), an acid reducer, belongs to histamine-2 receptor antagonists. Since 1981, even though several adverse effects of this drug were reported in the body, still, its effects on human sperm parameters have yet to be confirmed. In this work, we attempted to measure sperm motility, sperm vitality and activity of seminal creatine kinase in the ejaculated human semen (n = 31) in the presence of ranitidine at a range of concentrations (0.1, 0.3, 0.6, 0.9 and 1.2 µg/ml) compared with control (without ranitidine). Sperm motility was measured using the Makler counter, whilst sperm vitality was assessed using the Eosin test. Creatine kinase activity was measured using the kinetic spectrophotometric method. Sperm motility (total and progressive) as well as sperm vitality was significantly (p < .05) reduced in the presence of ranitidine in human semen, particularly at the higher tested concentrations (0.6-1.2 µg/ml) compared with the control. On the other hand, creatine kinase activity was significantly increased (p < .05) in the presence of ranitidine at 0.6, 0.9 and 1.2 µg/ml. In conclusion, ranitidine at 0.6-1.2 µg/ml reduced sperm motility and vitality, but increased the activity of creatine kinase in ejaculated human semen.