Computational redesign of cytochrome P450 CYP102A1 for highly stereoselective omeprazole hydroxylation by UniDesign.

Cytochrome P450 CYP102A1 is a prototypic biocatalyst that has great potential in chemical synthesis, drug discovery, and biotechnology. CYP102A1 variants engineered by directed evolution and/or rational design are capable of catalyzing the oxidation of a wide range of organic compounds. However, it is difficult to foresee the outcome of engineering CYP102A1 for a compound of interest. Here, we introduce UniDesign as a computational framework for enzyme design and engineering. We tested UniDesign by redesigning CYP102A1 for stereoselective metabolism of omeprazole (OMP), a proton pump inhibitor, starting from an active but nonstereoselective triple mutant (TM: A82F/F87V/L188Q). To shift stereoselectivity toward (R)-OMP, we computationally scanned three active site positions (75, 264, and 328) for mutations that would stabilize the binding of the transition state of (R)-OMP while destabilizing that of (S)-OMP and picked three variants, namely UD1 (TM/L75I), UD2 (TM/A264G), and UD3 (TM/A328V), for experimentation, based on computed energy scores and models. UD1, UD2, and UD3 exhibit high turnover rates of 55 ± 4.7, 84 ± 4.8, and 79 ± 5.7 min-1, respectively, for (R)-OMP hydroxylation, whereas the corresponding rates for (S)-OMP are only 2.2 ± 0.19, 6.0 ± 0.68, and 14 ± 2.8 min-1, yielding an enantiomeric excess value of 92, 87, and 70%, respectively. These results suggest the critical roles of L75I, A264G, and A328V in steering OMP in the optimal orientation for stereoselective oxidation and demonstrate the utility of UniDesign for engineering CYP102A1 to produce drug metabolites of interest. The results are discussed in the context of protein structures.

Th2 cytokine signaling through IL-4Rα increases eotaxin-3 secretion and tension in human esophageal smooth muscle.

In esophageal epithelial cells in eosinophilic esophagitis (EoE), Th2 cytokines (IL-4, IL-13) signal through IL-4Rα, activating JAK to increase eotaxin-3 secretion, which draws eosinophils into the mucosa. We explored whether Th2 cytokines also might stimulate eotaxin-3 secretion and increase tension in esophageal smooth muscle (ESM), which might impair esophageal distensibility, and whether those events could be blocked by proton pump inhibitors (PPIs) or agents that disrupt IL-4Rα signaling. We established human ESM cell cultures from organ donors, characterizing Th2 cytokine receptor and P-type ATPase expression by qPCR. We measured Th2 cytokine-stimulated eotaxin-3 secretion by enzyme-linked immunosorbent assay (ELISA) and ESM cell tension by gel contraction assay, before and after treatment with omeprazole, ruxolitinib (JAK inhibitor), or IL-4Rα blocking antibody. CPI-17 (inhibitor of a muscle-relaxing enzyme) effects were studied with CPI-17 knockdown by siRNA or CPI-17 phospho(T38A)-mutant overexpression. ESM cells expressed IL-4Rα and IL-13Rα1 but only minimal H+-K+-ATPase mRNA. Th2 cytokines increased ESM eotaxin-3 secretion and tension, effects blocked by ruxolitinib and IL-4Rα blocking antibody but not consistently blocked by omeprazole. IL-13 increased ESM tension by increasing CPI-17 expression and phosphorylation, effects blocked by CPI-17 knockdown. Blocking IL-4Rα decreased IL-13-stimulated eotaxin-3 secretion, CPI-17 expression, and tension in ESM. Th2 cytokines increase ESM eotaxin-3 secretion and tension via IL-4Rα signaling that activates CPI-17. Omeprazole does not reliably inhibit this process, but IL-4Rα blocking antibody does. This suggests that ESM eosinophilia and impaired esophageal distensibility might persist despite elimination of mucosal eosinophils by PPIs, and IL-4Rα blocking agents might be especially useful in this circumstance.NEW & NOTEWORTHY We have found that Th2 cytokines increase eotaxin-3 secretion and tension in esophageal smooth muscle (ESM) cells via IL-4Rα signaling. Unlike esophageal epithelial cells, ESM cells do not express H+-K+-ATPase, and omeprazole does not inhibit their cytokine-stimulated eotaxin-3 secretion or tension. An IL-4Rα blocking antibody reduces both eotaxin-3 secretion and tension induced by Th2 cytokines in ESM cells, suggesting that an agent such as dupilumab might be preferred for patients with EoE with esophageal muscle involvement.

Twice-Daily Proton Pump Inhibitor Induces Higher Remission Rate in Eosinophilic Esophagitis Than Once-Daily Regimen Regardless of Total Daily Dose.

INTRODUCTION: The optimal proton pump inhibitor (PPI) regimen for eosinophilic esophagitis (EoE) is unclear. We compared histologic response rates of different dosing combinations. METHODS: A total of 305 patients with newly diagnosed EoE received standard (omeprazole 20 mg daily), once-daily moderate (40 mg daily), twice-daily moderate (20 mg twice daily), or high (40 mg twice daily) dose PPI for ≥8 weeks. RESULTS: Approximately 42.3% achieved histologic response to PPI, with higher rates for twice-daily (moderate 52.8%/high 54.3%) than once-daily (standard 11.8%/moderate 10%) dosing ( P < 0.0001). On multivariable analysis, twice-daily moderate (adjusted odds ratio 6.75, confidence interval 2.53-18.0, P = 0.0008) and high (adjusted odds ratio 12.8, confidence interval 4.69-34.8, P < 0.0001) doses independently predicted histologic response. DISCUSSION: Twice-daily PPI is associated with higher EoE histologic response rates than once-daily regimen.

Omeprazole and risk of osteoarthritis: insights from a mendelian randomization study in the UK Biobank.

BACKGROUND: A former cohort study has raised concern regarding the unanticipated hazard of omeprazole in expediting osteoarthritis (OA) advancement. The precise nature of their causal evidence, however, remains undetermined. The present research endeavors to investigate the underlying causal link between omeprazole and OA through the application of mendelian randomization (MR) analysis. METHODS: The study incorporated the ukb-a-106 and ukb-b-14,486 datasets. The investigation of causal effects employed methodologies such as MR-Egger, Weighted median, Inverse variance weighted (IVW) with multiplicative random effects, and IVW (fixed effects). The IVW approach was predominantly considered for result interpretation. Sensitivity analysis was conducted, encompassing assessments for heterogeneity, horizontal pleiotropy, and the Leave-one-out techniques. RESULTS: The outcomes of the MR analysis indicated a causal relationship between omeprazole and OA, with omeprazole identified as a contributing risk factor for OA development (IVW model: OR = 1.2473, P < 0.01 in ukb-a-106; OR = 1.1288, P < 0.05 in ukb-b-14,486). The sensitivity analysis underscored the robustness and dependability of the above-mentioned analytical findings. CONCLUSION: This study, employing MR, reveals that omeprazole, as an exposure factor, elevates the risk of OA. Considering the drug's efficacy and associated adverse events, clinical practitioners should exercise caution regarding prolonged omeprazole use, particularly in populations with heightened OA risks. Further robust and high-quality research is warranted to validate our findings and guide clinical practice.

Arsenite-Induced Drug-Drug Interactions in Rats.

Arsenite is an important heavy metal. Some Chinese traditional medicines contain significant amounts of arsenite. The aim of this study was to investigate subacute exposure of arsenite on activities of cytochrome P450 enzymes and pharmacokinetic behaviors of drugs in rats. Midazolam, tolbutamide, metoprolol, omeprazole, caffeine, and chlorzoxazone, the probe substrates for cytochrome P450 (CYP) s3A, 2C6, 2D, 2C11, 1A, and 2E, were selected as probe drugs for the pharmacokinetic study. Significant decreases in areas under the curves of probe substrates were observed in rats after consecutive 30-day exposure to As at 12 mg/kg. Microsomal incubation study showed that the subacute exposure to arsenite resulted in little change in effects on the activities of P450 enzymes examined. However, everted gut sac study demonstrated that such exposure induced significant decreases in intestinal absorption of these drugs by both passive diffusion and carrier-mediated transport. In addition, in vivo study showed that the arsenite exposure decreased the rate of peristaltic propulsion. The decreases in intestinal permeability of the probe drugs and peristaltic propulsion rate most likely resulted in the observed decreases in the internal exposure of the probe drugs. Exposure to arsenite may lead to the reduction of the efficiencies of pharmaceutical agents coadministered resulting from the observed drug-drug interactions. SIGNIFICANCE STATEMENT: Exposure to arsenite may lead to the reduction of the efficiencies of pharmaceutical agents coadministered resulting from the observed drug-drug interactions. The present study, we found that P450 enzyme probe drug exposure was reduced in arsenic-exposed animals (areas under the curve) and the intestinal absorption of the drug was reduced in the animals. Subacute arsenic exposure tends to cause damage to intestinal function, which leads to reduced drug absorption.

CYP7A1 Gene Induction via SHP-Dependent or Independent Mechanisms can Increase the Risk of Drug-Induced Liver Injury Independently or in Synergy with BSEP Inhibition.

Drug-induced liver injury (DILI) is a frequent cause of clinical trial failures during drug development. While inhibiting bile salt export pump (BSEP) is a well-documented DILI mechanism, interference with genes related to bile acid (BA) metabolism and transport can further complicate DILI development. Here, the effects of twenty-eight compounds on genes associated with BA metabolism and transport were evaluated, including those with discontinued development or use, boxed warnings, and clean labels for DILI. The study also included rifampicin and omeprazole, pregnane X receptor and aryl hydrocarbon receptor ligands, and four mitogen-activated protein kinase kinase (MEK1/2) inhibitors. BSEP inhibitors with more severe DILI, notably pazopanib and CP-724714, significantly upregulated the expression of 7 alpha-hydroxylase (CYP7A1), independent of small heterodimer partner (SHP) expression. CYP7A1 expression was marginally induced by omeprazole. In contrast, its expression was suppressed by mometasone (10-fold), vinblastine (18-fold), hexachlorophene (2-fold), bosentan (2.1-fold), and rifampin (2-fold). All four MEK1/2 inhibitors that show clinical DILI were not potent BSEP inhibitors but significantly induced CYP7A1 expression, accompanied by a significant SHP gene suppression. Sulfotransferase 2A1 and BSEP were marginally upregulated, but no other genes were altered by the drugs tested. Protein levels of CYP7A1 were increased with the treatment of CYP7A1 inducers and decreased with obeticholic acid, an farnesoid X receptor ligand. CYP7A1 inducers significantly increased bile acid (BA) production in hepatocytes, indicating the overall regulatory effects of BA metabolism. This study demonstrates that CYP7A1 induction via various mechanisms can pose a risk for DILI, independently or in synergy with BSEP inhibition, and it should be evaluated early in drug discovery. SIGNIFICANCE STATEMENT: Kinase inhibitors, pazopanib and CP-724714, inhibit BSEP and induce CYP7A1 expression independent of small heterodimer partner (SHP) expression, leading to increased bile acid (BA) production and demonstrating clinically elevated drug-induced liver toxicity. MEK1/2 inhibitors that show BSEP-independent drug-induced liver injury (DILI) induced the CYP7A1 gene accompanied by SHP suppression. CYP7A1 induction via SHP-dependent or independent mechanisms can pose a risk for DILI, independently or in synergy with BSEP inhibition. Monitoring BA production in hepatocytes can reliably detect the total effects of BA-related gene regulation for de-risking.

Novel Cytochrome P450 2C119 Enzymes in Cynomolgus and Rhesus Macaques Metabolize Progesterone, Diclofenac, and Omeprazole.

Cynomolgus and rhesus macaques are used in drug metabolism studies due to their evolutionary and phylogenetic closeness to humans. Cytochromes P450 (P450s or CYPs), including the CYP2C family enzyme, are important endogenous and exogenous substrate-metabolizing enzymes and play major roles in drug metabolism. In cynomolgus and rhesus macaques, six CYP2Cs have been identified and characterized, namely, CYP2C8, CYP2C9, CYP2C18, CYP2C19, CYP2C76, and CYP2C93. In this study, CYP2C119, a new CYP2C, was identified and characterized in cynomolgus and rhesus macaques. Cynomolgus and rhesus CYP2C119 contained open reading frames of 489 amino acids with high sequence identities to human CYP2C8 and to cynomolgus and rhesus CYP2C8. Phylogenetic analysis showed that cynomolgus and rhesus CYP2C119 were closely related to cynomolgus and rhesus CYP2C8. In cynomolgus and rhesus genomes, CYP2C genes, including CYP2C119, form a cluster. Among the tissues analyzed, cynomolgus CYP2C119 mRNA was predominantly expressed in liver. Hepatic expressions of CYP2C119 mRNA in four cynomolgus and two rhesus macaques varied, with no expression in one rhesus macaque. Among the CYP2C mRNAs, CYP2C119 mRNA was expressed less abundantly than CYP2C8, CYP2C9, CYP2C19, and CYP2C76 mRNAs but more abundantly than CYP2C18 mRNA. Recombinant cynomolgus and rhesus CYP2C119 catalyzed progesterone 16α-, 17α-, and 21-hydroxylation and diclofenac and omeprazole oxidations, indicating that CYP2C119 is a functional enzyme. Therefore, the novel CYP2C119 gene, expressed in macaque liver, encodes a functional enzyme that metabolizes human CYP2C substrates and is likely responsible for drug clearances. SIGNIFICANCE STATEMENT: Cytochrome P450 2C119 was found in cynomolgus and rhesus macaques, in addition to the known P450 2C8, 2C9, 2C18, 2C19, 2C76, and 2C93. Cynomolgus and rhesus CYP2C119 contain open reading frames of 489 amino acids with high sequence identity to human CYP2C8. Cynomolgus CYP2C119 mRNA is predominantly expressed in the liver. Recombinant CYP2C119 catalyzed progesterone hydroxylation and diclofenac and omeprazole oxidations. Therefore, the novel CYP2C119 gene expressed in the macaque liver encodes a functional enzyme that metabolizes human CYP2C substrates.

Omeprazole-Associated Atypical Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) in a Patient with Positive In Vitro Diagnostic Testing to Multiple Proton Pump Inhibitors.

Proton pump inhibitors (PPIs) are a commonly used class of drugs with a good safety profile. However, their use is associated with rare cases of severe skin reaction. Herein, we present details of a patient who developed two episodes of omeprazole-induced delayed-onset hypersensitivity (atypical drug reaction with eosinophilia and systemic symptoms [DRESS]). Lymphocytes from the patient were stimulated to proliferate and secrete cytokines and cytolytic molecules when treated with the drug. T-cell cross-reactivity was observed with structurally related PPIs. Hence, other PPIs have the potential to cause further serious immune-related adverse events in patients who present with hypersensitivity to a primary PPI.

Structure-Guided Evolution of Cyclohexanone Monooxygenase Toward Bulky Omeprazole Sulfide: Substrate Migration and Stereoselectivity Inversion.

Structure-guided engineering of a CHMO from Amycolatopsis methanolica (AmCHMO) was performed for asymmetric sulfoxidation activity and stereoselectivity toward omeprazole sulfide. Initially, combinatorial active-site saturation test (CASTing) and iteratively saturation mutagenesis (ISM) were performed on 5 residues at the "bottleneck" of substrate tunnel, and MT3 was successfully obtained with a specific activity of 46.19 U/g and R-stereoselectivity of 99 % toward OPS. Then, 4 key mutations affecting the stereoselectivity were identified through multiple rounds of ISM on residues at the substrate binding pocket region, resulting MT8 with an inversed stereoselectivity from 99 % (R) to 97 % (S). MT8 has a greatly compromised specific activity of 0.08 U/g. By introducing additional beneficial mutations, MT11 was constructed with significantly increased specific activity of 2.29 U/g and stereoselectivity of 97 % (S). Enlarged substrate tunnel is critical to the expanded substrate spectrum of AmCHMO, while reshaping of substrate binding pocket is important for stereoselective inversion. Based on MD simulation, pre-reaction states of MT3-OPSproR, MT8-OPSproS, and MT11-OPSproS were calculated to be 45.56 %, 17.94 %, and 28.65 % respectively, which further confirm the experimental data on activity and stereoselectivity. Our results pave the way for engineering distinct activity and stereoselectivity of BVMOs toward bulky prazole thioethers.

KRAS-mutant non-small cell lung cancer (NSCLC) therapy based on tepotinib and omeprazole combination.

BACKGROUND: KRAS-mutant non-small cell lung cancer (NSCLC) shows a relatively low response rate to chemotherapy, immunotherapy and KRAS-G12C selective inhibitors, leading to short median progression-free survival, and overall survival. The MET receptor tyrosine kinase (c-MET), the cognate receptor of hepatocyte growth factor (HGF), was reported to be overexpressed in KRAS-mutant lung cancer cells leading to tumor-growth in anchorage-independent conditions. METHODS: Cell viability assay and synergy analysis were carried out in native, sotorasib and trametinib-resistant KRAS-mutant NSCLC cell lines. Colony formation assays and Western blot analysis were also performed. RNA isolation from tumors of KRAS-mutant NSCLC patients was performed and KRAS and MET mRNA expression was determined by real-time RT-qPCR. In vivo studies were conducted in NSCLC (NCI-H358) cell-derived tumor xenograft model. RESULTS: Our research has shown promising activity of omeprazole, a V-ATPase-driven proton pump inhibitor with potential anti-cancer properties, in combination with the MET inhibitor tepotinib in KRAS-mutant G12C and non-G12C NSCLC cell lines, as well as in G12C inhibitor (AMG510, sotorasib) and MEK inhibitor (trametinib)-resistant cell lines. Moreover, in a xenograft mouse model, combination of omeprazole plus tepotinib caused tumor growth regression. We observed that the combination of these two drugs downregulates phosphorylation of the glycolytic enzyme enolase 1 (ENO1) and the low-density lipoprotein receptor-related protein (LRP) 5/6 in the H358 KRAS G12C cell line, but not in the H358 sotorasib resistant, indicating that the effect of the combination could be independent of ENO1. In addition, we examined the probability of recurrence-free survival and overall survival in 40 early lung adenocarcinoma patients with KRAS G12C mutation stratified by KRAS and MET mRNA levels. Significant differences were observed in recurrence-free survival according to high levels of KRAS mRNA expression. Hazard ratio (HR) of recurrence-free survival was 7.291 (p = 0.014) for high levels of KRAS mRNA expression and 3.742 (p = 0.052) for high MET mRNA expression. CONCLUSIONS: We posit that the combination of the V-ATPase inhibitor omeprazole plus tepotinib warrants further assessment in KRAS-mutant G12C and non G12C cell lines, including those resistant to the covalent KRAS G12C inhibitors.

Inhibitors of gastric acid secretion increase oxidative stress and matrix metalloproteinase-2 activity leading to vascular remodeling.

The use of inhibitors of gastric acid secretion (IGAS), especially proton pump inhibitors (PPI), has been associated with increased cardiovascular risk. While the mechanisms involved are not known, there is evidence supporting increased oxidative stress, a major activator of matrix metalloproteinases (MMP), as an important player in such effect. However, there is no study showing whether other IGAS such as histamine H2-receptor blockers (H2RB) cause similar effects. This study aimed at examining whether treatment with the H2RB ranitidine promotes oxidative stress resulting in vascular MMP activation and corresponding functional and structural alterations in the vasculature, as compared with those found with the PPI omeprazole. Male Wistar rats were treated (4 weeks) with vehicle (2% tween 20), omeprazole (10 mg/Kg/day; i.p.) or ranitidine (100 mg/Kg/day; gavage). Then the aorta was collected to perform functional, biochemical, and morphometric analysis. Both ranitidine and omeprazole increased gastric pH and oxidative stress assessed in situ with the fluorescent dye dihydroethidium (DHE) and with lucigenin chemiluminescence assay. Both IGAS augmented vascular activated MMP-2. These findings were associated with aortic remodeling (increased media/lumen ratio and number of cells/µm2). Both IGAS also impaired the endothelium-dependent relaxation induced by acetylcholine (isolated aortic ring preparation). This study provides evidence that the H2RB ranitidine induces vascular dysfunction, redox alterations, and remodeling similar to those found with the PPI omeprazole. These findings strongly suggest that IGAS increase oxidative stress and matrix metalloproteinase-2 activity leading to vascular remodeling, which helps to explain the increased cardiovascular risk associated with the use of those drugs.

Inflammation-mediated drug interactions of olokizumab and cytochrome P450 activities in patients with rheumatoid arthritis.

AIMS: In patients with rheumatoid arthritis (RA), interleukin (IL)-6 affects the activity of cytochrome P450 (CYP) enzymes. Treatment with anti-IL-6 therapy can reverse the IL-6-mediated downregulation of CYP enzymes, resulting in changes in plasma levels of CYP substrates. The primary objective of this study was to evaluate the impact of the IL-6 inhibitor olokizumab on the pharmacokinetics of CYP probe substrates in subjects with active RA. METHODS: Seventeen patients with active RA were orally administered a phenotyping cocktail of midazolam (CYP3A4 substrate), omeprazole (CYP2C19 substrate), warfarin (CYP2C9 substrate) and caffeine (CYP1A2 substrate) alone and 2 weeks after a single subcutaneous injection of 128 mg olokizumab. The pharmacokinetic parameters of each substrate were calculated using noncompartmental analysis. RESULTS: Sixteen of 17 enrolled patients received the complete doses of the cocktail drugs and olokizumab and were eligible for the pharmacokinetic evaluations. After single-dose administration of olokizumab, the exposure of midazolam and omeprazole decreased by 30-33% and 26-32%, respectively, compared to when the substrates were administered along via cocktail. In the presence of olokizumab, caffeine exposure increased by 19-23% compared to caffeine administration alone. There were no significant changes in S-warfarin exposure. CONCLUSION: In patients with active RA, olokizumab potentially reverses the IL-6-mediated suppression of CYP3A4 and CYP2C19. According to FDA guidance, olokizumab is considered a weak inducer of CYP3A4 and CYP2C19.

Omeprazole affects the expression of serotonin-1A in the brain regions and alleviates anxiety in rat model of immobilization-induced stress.

Omeprazole, a drug of choice for the management of gastric hyperacidity, influences serotonergic neurotransmission in brain regions and its long-term use is known to cause stress-related behavioral deficits including anxiety. Aim of the current study was to explore the effects of omeprazole treatment on immobilization-induced anxiety in rats, specifically on the role of serotonin (5-HT). In view of the role of serotonin-1A (5-HT1A) autoreceptor in the availability of 5-HT in brain regions, mRNA expression of this autoreceptor was performed in raphe nuclei. Similarly, because of the role of hippocampal 5-HT neurotransmission in anxiety-like disorders, expression of the 5-HT1A heteroreceptors was determined in this region. We found that the treatment with omeprazole reduces anxiety-like behavior in rats, increases the expression of 5-HT1A autoreceptor in the raphe and decreases the hippocampal expression of 5-HT1A heteroreceptor. This suggests a role of 5-HT1A receptor types in omeprazole-induced behavioral changes. It also indicates a potential role of omeprazole in the management of serotonergic disorders.

The protective effects of Gamma-linolenic acid against indomethacin-induced gastric ulcer in rats.

The primary goal of the investigation was to analyse the anti-inflammatory and antioxidant properties of Gamma-linolenic acid (GLA) on rats with indomethacin (IND)-induced gastric ulcers. Thirty rats were divided into five groups: Control, IND (50 mg/kg, p.o.), IND pretreated with GLA 100 mg/kg (p.o. for 14 d), IND pretreated with GLA 150 mg/kg (p.o. for 14 d) and IND pretreated with omeprazole (20 mg/kg, p.o. for 14 d). The stomach tissues were examined to calculate the ulcer index and pH and analyse biochemical markers (prostaglandin E2 (PGE2), cyclooxygenase 1 (COX1), TNF-1, IL-6 and intercellular adhesion molecule-1 (ICAM1)) and oxidative stress parameters (malondialdehyde: (MDA), superoxide dismutase (SOD), glutathione (GSH) and CAT (catalase)) as well as undergo histopathological assessment. GLA 100 and 150 mg/kg showed a protective effect against IND-induced gastric damage. It reduced levels of COX1, TNF-1, IL-6 and ICAM and increased PGE2 levels. GLA also normalised antioxidant function by modulating MDA, SOD, GSH and CAT. GLA intervention protects against IND-induced gastric ulcers by restoring oxidant/antioxidant balance and reducing inflammation.

Omeprazole taken once every other day can effectively prevent aspirin-induced gastrointestinal mucosal damage in rats.

BACKGROUND: Proton-pump inhibitors (PPIs) prevent aspirin-associated gastric and duodenal mucosal damage. However, long-term use of PPIs can lead to various adverse reactions, such as gastric polyps and enterochromaffin-like cell hyperplasia. Current research indicates that the abovementioned adverse reactions are mainly related to hypergastrinemia. We investigated whether low-frequency administration of omeprazole could effectively repair aspirin-induced mucosal damage and reduce the increase in gastrin levels associated with long-term use of PPIs. METHODS: Sprague‒Dawley rats were divided into four treatment groups: daily aspirin, daily aspirin and omeprazole once every day (qd), daily aspirin and omeprazole once every other day (qod), and daily aspirin and omeprazole once every three days (1/d3). After 15 days of feeding, blood samples were collected, and the stomachs of sacrificed rats were subjected to macroscopic, histological, and immunohistochemical studies. Moreover, in clinical practice, patients with peptic ulcers caused by aspirin took a standard dose of omeprazole (20 mg) every other day. Two months later, gastroscopy was performed to examine the healing of the ulcers. RESULTS: Both the omeprazole qd and omeprazole qod administrations effectively prevented aspirin-induced gastric peptic ulcers, with no significant difference between the two groups in the inhibition of parietal cell secretion of gastric acid and cell apoptosis. However, omeprazole 1/d3 failed to completely prevent aspirin-induced gastric mucosal injury. Notably, the gastrin levels, cell proliferation ability and cholecystokinin B receptor expression of the omeprazole qd group were significantly higher than those of the omeprazole qod group. In clinical work, patients with peptic ulcers caused by aspirin were given a standard dose of omeprazole every other day, and their ulcers healed after 2 months, as observed by gastroscopy. CONCLUSIONS: Omeprazole administration once every other day can effectively prevent aspirin-induced peptic ulcers and reduce hypergastrinemia, which may reduce the long-term adverse effects of PPI treatment.

A pharmacovigilance study of association between proton-pump inhibitors and rhabdomyolysis event based on FAERS database.

BACKGROUND AND AIM: The association between proton-pump inhibitors (PPIs) and rhabdomyolysis were unclear. The aim of this study was to explore and systematically analyze the potential link between five PPIs and the rhabdomyolysis events using the FDA Adverse Event Reporting System (FAERS) database. METHODS: Suspected rhabdomyolysis events associated with PPIs were identified by data mining with the reporting odds ratio (ROR), proportional reporting ratio (PRR), the information component (IC), and Empirical Bayes Geometric Mean (EBGM). Demographic information, drug administration, and outcomes of PPI-induced rhabdomyolysis events were also analyzed. RESULTS: There were 3311 reports associated with PPI-induced rhabdomyolysis that were identified. After removing duplicates, 1899 cases were determined to contain complete patient demographic data. The average age was 65 ± 18 year and 57% were male. Omeprazole and pantoprazole had the same largest percentage of reports. Lansoprazole had the highest ROR index of 12.67, followed by esomeprazole (11.18), omeprazole (10.27), rabeprazole (10.06), and pantoprazole (9.24). PRR, IC, and EBGM showed similar patterns. This suggested that lansoprazole exhibited the strongest correlation with rhabdomyolysis. In rhabdomyolysis events, PPIs were mainly "concomitant" (>60%), and only a few cases were "primary suspects" (<15%). Rabeprazole showed the lowest death rate while lansoprazole showed the highest. CONCLUSIONS: The study suggested that significant rhabdomyolysis signals were associated with PPIs. Further research should be performed in drug safety evaluation for a more comprehensive association.

The benefit of omeprazole exposure on all-cause mortality and length of ICU/hospital stay might vary with age in critically ill pediatric patients: A cohort study.

PURPOSE: To investigate the association between proton pump inhibitors (PPIs) administration during hospitalization and mortality and length of stay in critically ill pediatric patients. MATERIALS AND METHODS: This is a retrospective observational cohort study on pediatric ICU patients (0 to 18 years). Propensity score matching (PSM), Kaplan-Meier curves, Cox proportional hazards model and Linear regression model was applied for assessing the effects of PPIs on mortality and other outcomes during hospitalization. RESULTS: A total of 2269 pediatric ICU patients were included, involving 1378 omeprazole (OME) users and 891 non-OME users. The results showed significant association between OME exposure and decreased ICU stay (ß -0.042; 95% CI -0.073--0.011; P = 0.008) but prolonged non-ICU hospital stay (ß 0.121; 95% CI 0.097-0.155; P = 0.040). No statistical significance was observed between OME exposure and reduced mortality, but the OME group had a slightly decreased tendency in 28-day mortality (HR 0.701; 95% CI 0.418-1.176) and in-hospital mortality (HR 0.726; 95% CI 0.419-1.257). Furthermore, subgroup analyses revealed that the decreased tendency of mortality were more obvious in patients less than 1 year old compared with older pediatric patients, although not statistically significant. In addition, we also observed that OME exposure was significantly associated with reduced mortality of general ICU subgroup. CONCLUSIONS: This study provided a sign that PPIs used only in the ICU, rather than throughout hospital stay, might provide more benefit for critically ill pediatric patients. Additionally, younger pediatric patients might gain relatively more benefit than older children when receiving PPIs.

Temporal trends in use of antisecretory agents among patients administered clopidogrel-based dual antiplatelet therapy after percutaneous coronary intervention.

BACKGROUND: Antisecretory drugs are commonly prescribed with clopidogrel-based dual antiplatelet therapy (DAPT) to prevent gastrointestinal bleeding in high-risk patients after percutaneous coronary intervention (PCI). However, omeprazole and esomeprazole (inhibiting proton pump inhibitors [PPIs]) may increase cardiovascular event rates on co-administration with clopidogrel. This study aimed to examine trends in the use of antisecretory agents in patients administered clopidogrel-based DAPT and the concomitant use of clopidogrel and inhibiting PPIs. METHODS: We used National Inpatient Sample data compiled by the Health Insurance Review & Assessment Service from 2009 to 2020. Further, we identified patients who were prescribed clopidogrel-based DAPT after PCI and investigated the concomitant use of antisecretory agents with clopidogrel. To verify the annual trend of drug utilization, we used the Cochran-Armitage trend test. RESULTS: From 2009 to 2020, the percentage of H2 receptor antagonist users decreased steadily (from 82.5% in 2009 to 25.3% in 2020); instead, the percentage of PPI users increased (from 23.7% in 2009 to 82.0% in 2020). The use of inhibiting PPI also increased (from 4.2% in 2009 to 30.7% in 2020). Potassium competitive acid blockers (P-CABs) were rarely used before 2019; however, in 2020, it accounted for 7.8% of the antisecretory users. CONCLUSIONS: Our study demonstrates that the use of inhibiting PPIs increased steadily in patients administered clopidogrel-based DAPT therapy. This is a major concern since the concomitant use of inhibiting PPIs with clopidogrel could increase the risk of cardiovascular events.

Modeled Hepatic/Plasma Exposures of Omeprazole Prescribed Alone in Cytochrome P450 2C19 Poor Metabolizers Are Likely Associated with Hepatic Toxicity Reported in a Japanese Adverse Event Database.

Omeprazole, a gastric acid pump inhibitor, is repeatedly administered and is oxidatively metabolized mainly by polymorphic cytochrome P450 2C19. The prescribed dosage of omeprazole was discontinued or reduced in 47 of the 135 patients who received omeprazole alone in this survey, as recorded in the Japanese Adverse Drug Event Report database. The days to onset of omeprazole-related disorders were 3-4 d (median) and 16 d for intravenous 20-40 mg and oral 20 mg daily doses, respectively, in 34 patients for whom relevant data were available. The maximum plasma concentration of omeprazole was pharmacokinetically modeled after a single oral 40-mg dose in P450 2C19-defective poor metabolizers and was 2.4-fold higher than that in extensive metabolizers. The modeled area under the hepatic concentration curves of omeprazole in P450 2C19 poor metabolizers after virtual daily 40-mg doses for 7 d was 5.2-fold higher than that in the extensive metabolizers. Omeprazole-induced P450 2C19 (approx. 2-fold), resulting in increased hepatic intrinsic clearance in repeated doses, was considered after the second day. Virtual plasma/hepatic exposure estimated using pharmacokinetic modeling in subjects with P450 2C19 poor metabolizers indicated that these exposure levels virtually estimated could be one of causal factors for unexpected hepatic disorders induced by prescribed omeprazole, such as those resulting from drug interactions with repeatedly co-administered medicines.

Omeprazole Induces CYP3A4 mRNA Expression but Not CYP3A4 Protein Expression in HepaRG Cells.

Unknown interactions between drugs remain the limiting factor for clinical application of drugs, and the induction and inhibition of drug-metabolizing CYP enzymes are considered the key to examining the drug-drug interaction (DDI). In this study, using human HepaRG cells as an in vitro model system, we analyzed the potential DDI based on the expression levels of CYP3A4 and CYP1A2. Rifampicin and omeprazole, the potent inducers for CYP3A4 and CYP1A2, respectively, induce expression of the corresponding CYP enzymes at both the mRNA and protein levels. We noticed that, in addition to inducing CYP1A2, omeprazole induced CYP3A4 mRNA expression in HepaRG cells. However, unexpectedly, CYP3A4 protein expression levels were not increased after omeprazole treatment. Concurrent administration of rifampicin and omeprazole showed an inhibitory effect of omeprazole on the CYP3A4 protein expression induced by rifampicin, while its mRNA induction remained intact. Cycloheximide chase assay revealed increased CYP3A4 protein degradation in the cells exposed to omeprazole. The data presented here suggest the potential importance of broadening the current DDI examination beyond conventional transcriptional induction and enzyme-activity inhibition tests to include post-translational regulation analysis of CYP enzyme expression.