Polymorphism of CYP2C19 and gastric emptying in patients with proton pump inhibitor-resistant gastric ulcers

P-CAB versus PPI in the eradication of Helicobacter pylori: a systematic review and network meta-analysis

Background

The efficacy and safety of potassium-competitive acid blockers (P-CABs) in the eradication of Helicobacter pylori (Hp) remains controversial when compared with proton pump inhibitors (PPIs).

Objectives

The current study set out to compare the differences in the eradication rate and adverse reactions between eradication regimens based on P-CAB or PPI drugs and the differences between the vonoprazan-based and the tegoprazan-based regimens to explore the efficacy and safety of different Hp eradication regimens.

Data sources and methods

Databases including PubMed, EMBASE, Cochrane Library, and WOS were searched from the inception of these databases up to July 2023, and eligible randomized controlled trials (RCTs) were included. The outcome measures were the eradication rate and the incidence of adverse reactions of different regimens in treating Hp. The results were estimated as relative risk (RR) and its 95% confidence interval (CI), and R 4.2.1 software was used to perform the network meta-analysis (NMA).

Results

A total of 20 studies were included in the analysis, involving 5815 patients with Hp. In terms of eradication rate, the 2-week vonoprazan-based triple regimen (V-Tri-2w) was the best, which was superior to the 2-week PPI-based quadruple regimen [P-Qua-2w, RR = 0.9, 95% CI: (0.85-0.95)] and the 1-week tegoprazan-based triple regimen [T-Tri-1w, RR = 0.79, 95% CI: (0.64-0.97)]; the 2-week tegoprazan-based quadruple regimen (T-Qua-2w) was superior to the 1-week PPI-based triple regimen [P-Tri-1w, RR = 0.82, 95% CI: (0.67-0.99)], and there was no difference between the remaining tegoprazan-based regimens and the PPI-based or vonoprazan-based regimens. In terms of the incidence of adverse reactions, the 2-week vonoprazan-based binary regimen (V-Bi-2w) was lower than that of the 2-week PPI-based quadruple regimen [P-Qua-2w, RR = 1.98, 95% CI: (1.57-2.52)]; there was no significant difference between 1 and 2 weeks for each regimen, such as the vonoprazan-based triple regimen [RR = 1.11, 95% CI: (0.82-1.52)].

Conclusion

In the eradication treatment of Hp, the efficacy and safety of vonoprazan-based regimens are generally better than those of PPI-based regimens. Among them, the V-Tri-2w regimen has the highest eradication rate and may be the preferred choice for Hp eradication.

Gastric emptying time of fluids and solids in healthy subjects determined by 13C breath tests: influence of age, sex and body mass index

BACKGROUND AND AIM

Disturbance of gastric emptying leads to a variety of symptoms. Furthermore, gastric motility disorders might play a role in the pathophysiology of functional dyspepsia. In previous studies 13C breath tests were validated as non-invasive tools in the measurement of gastric emptying time. So far, reliable reference values of healthy subjects are missing and the impact of constitutional traits (age, sex, body mass index [BMI]) needs to be clarified.

METHODS

A study was conducted in 90 healthy individuals (45 men, 45 women) that assessed the correlation of parameters of gastric emptying (half gastric emptying time [T1/2] and time of fastest gastric emptying [T(lag)]) with age, sex and BMI for fluid and solid test meals by 13C breath tests. 100 mg of sodium acetate or sodium octanoate, respectively, were used as tracers. Breath probes were analyzed by non-dispersive infrared spectroscopy.

RESULTS

The mean +/- SD of half gastric emptying time (T1/2) of a fluid test meal was determined to be 80.5 +/- 22.1 min and for T(lag) to be 40.3 +/- 10.2 min. However, the T1/2 and T(lag) of solid meals did not fit to normal distribution and thus median and percentiles were determined. The median time of T1/2 for solids was 127 min (25-75% percentiles: 112.0-168.3 min) and 81.5 min for T(lag) (25-75% percentiles: 65.5-102.0 min). No significant correlation was found between gastric emptying and age, sex or BMI.

CONCLUSION

This is the first study to examine gastric emptying in an adequate number of healthy subjects by 13C breath tests. No significant correlation was found with age, sex and BMI. Although there is considerable standard deviation in gastric emptying time, these results may nevertheless serve as reference values for further studies.

Papel del polimorfismo genético CYP2C19 en los efectos adversos a fármacos y en el riesgo para diversas enfermedades

There are a great number of polymorphic genes in the human genome. Many of them codify enzymes that metabolizes drugs and xenobiotic agents, including carcinogens. Among the better known of them, there are a number of isozymes of the microsomal oxidative system (CYP3A4, CYP2C9, CYP2C19 y CYP2D6). This article reviews the following issues: a) frequency of presentation of the "poor metabolizer" genotype and/or phenotype for substrates of CYP2C19; b) role of CYP2C19 polymorphism on the metabolism of some drugs (mephenytoine and other antiepileptic drugs, proton pump inhibitors, several antidepressants and anxyolitics, the antimalaria aggent proguanyl, and propranolol, among others, use this metabolic pathway), and c) possible role of CYP2C19 polymorphism in the risk for development of neoplasia and other diseases (systemic lupus erythematosus, psoriasis, hip osteonecrosis, Alzheimer's disease, amyotrophic lateral sclerosis, essential tremor).

Genetic polymorphism analysis of cytochrome P4502C19 in Chinese Uigur and Han populations

OBJECTIVE

To assess the genotype patterns of cytochrome P4502C19 in the Chinese Uigur and Han populations and compare them with other populations.

METHODS

Ninety-six Uigur and 104 Han healthy, unrelated subjects (Uigur: 51 males, 45 females, aged from 23 to 30 years; Han: 53 males, 51 females, aged from 21 to 26 years) were genotyped for CYP2C19 by the PCR-RFLP technique to identify the wild-type (wt) gene and two mutations, CYP2C19m1 in exon5 and CYP2C19m2 in exon 4.

RESULTS

In the Uigur, the incidence of the poor metabolizer phenotype was 4.17% (4 of 96 subjects with m1/m1 genotype) and that of the extensive metabolizer was 95.83% (92 of 96 subjects), consisting of 6 (6.25%) homozygous for CYP2C19wt (wt/wt) in both exon 4 and exon 5, 83 (86.46%) heterozygous for CYP2C19wt and CYP2C19m1 and 3 (3.13%) heterozygous for both wt/m1 and wt/m2. None of the Uigur subjects was homozygous for CYP2C19m2 (m2/m2) or heterozygous for wt/m2 or m1/m2. Thus in the Uigur, the frequency of the CYP2C19m1 allele was 0.4818, the CYP2C19m2 allele was 0.0078, and that of the CYP2C19wt was 0.5104. In the Han, the frequency of the CYP2C19m1 allele was 0.3333, the CYP2C19m2 allele was 0.0686, and the frequency of the CYP2C19wt was 0.6058. CYP2C19m1 was the majority of the two mutations found in the Uigur, which was consistent with the situation in the Han population, and the frequency of the CYP2C19m1 allele was approximately 60-fold that of the mutant allele CYP2C19m2. On the other hand, there were significant interethnic differences when the Uigur population was compared with other minorities with regard to the CYP2C19 genotype.

CONCLUSIONS

The results indicate that the distribution frequency of the poor and the extensive metabolizers in the Uigur population is significantly lower and higher, respectively (P < 0.025), than in the Han population. There are significant differences between the Uigur and Han populations regarding the CYP2C19 allele frequency, which is consistent with results for the Caucasian population. On the other hand, there are significant interethnic differences when the Uigur population is compared with the Miao and Dai populations.