The prevalence of gastroesophageal reflux disease (GERD) in South Korea has increased over the past 10 years. Patients with erosive reflux disease (ERD) shows better response to proton pump inhibitors (PPIs) than those with non-erosive reflux disease (NERD). NERD is a heterogeneous condition, showing pathological gastroesophageal reflux or esophageal hypersensitivity to reflux contents. NERD patients with pathological gastroesophageal reflux or hypersensitivity to acid may respond to PPIs. However, many patients with esophageal hypersensitivity to nonacid or functional heartburn do not respond to PPIs. Therefore, careful history and investigations are required when managing patients with refractory GERD who show poor response to conventional dose PPIs. Combined pH-impedance studies and a PPI diagnostic trial are recommended to reveal underlying mechanisms of refractory symptoms. For those with ongoing reflux-related symptoms, split dose administration, change to long-acting PPIs or PPIs less influenced by CYP2C19 genotypes, increasing dose of PPIs, and the addition of alginate preparations, prokinetics, selective serotonin reuptake inhibitors, or tricyclic antidepressants can be considered. Pain modulators, selective serotonin reuptake inhibitors, or tricyclic antidepressants are more likely to be effective for those with reflux-unrelated symptoms. Surgery or endoscopic per oral fundoplication may be effective in selected patients.
Anti-Ulcer Agents/therapeutic use ; Cytochrome P-450 CYP2C19/genetics ; Esophageal pH Monitoring ; Gastroesophageal Reflux/drug therapy/metabolism/*pathology ; Genotype ; Heartburn ; Humans ; Proton Pump Inhibitors/therapeutic use

<p>OBJECTIVETo detect the single nucleotide polymorphisms of clopidogrel metabolism related genes (CYP2C19, ABCB1 and PON1) in Chinese patients with acute coronary syndrome (ACS) by genotype analysis.p><p>METHODSGenetic analysis was performed in patients admitted to Fuwai Hospital from 2005 to 2008 with ACS within 4 weeks. The detection of polymorphisms was performed by TaqMan real-time PCR method. The alleles genotyped were CYP2C19 *2-*8, *17, ABCB1 C3435T, PON1 Q192R and PON1 L55M. Minor allele frequency (MAF) was calculated. Patients were classified as one of the 5 categories by clopidogrel metabolizer phenotypes as extensive [without any "loss-of-function" (LOF) allele *2-*8 or "gain-of-function" (GOF) allele *17], intermediate (with only one LOF allele), Poor (with two or more LOF alleles), ultra (with one or two GOF alleles) or unknown (with one LOF allele and one GOF allele).p><p>RESULTSA total of 2800 ACS patients were enrolled [mean age (59.0 ± 12.3) years and 2236 males (79.9%)]. There were 74% patients with ST-segment elevation myocardial infarction (STEMI, n = 2072), 22.0% patients with non-ST-segment elevation myocardial infarction (NSTEMI, n = 617) and 4.0% patients with unstable angina (UA, n = 111). The minor allele frequency (MAF) for each genotype of CYP2C19 *2, *3, *4, *17 was 28.7%, 4.6%, 0.1% and 1.2%, respectively. There was no LOF allele *5-*8 in the study population. The MAF for ABCB1 C3435T, PON1 Q192R and PON1 L55M was 39.4%, 37.8% and 4.4%, respectively. Clopidogrel metabolizer groups were defined as extensive in 41.7%, intermediate in 45.6%, poor in 10.3%, ultra in 1.9% and unknown in 0.6% patients, respectively. There were no significant differences for all genotypes between males and females. Total LOF carriers of CYP2C19 were 56.4% and GOF carriers were 2.5%.p><p>CONCLUSIONSOur study demonstrated a high distribution of the LOF allele of CYP2C19 in China ACS population.p>
Acute Coronary Syndrome ; genetics ; metabolism ; Aged ; Alleles ; Aryl Hydrocarbon Hydroxylases ; genetics ; Aryldialkylphosphatase ; genetics ; Asian Continental Ancestry Group ; genetics ; Cytochrome P-450 CYP2C19 ; Female ; Gene Frequency ; Genotype ; Humans ; Male ; Middle Aged ; Polymorphism, Single Nucleotide ; Ticlopidine ; analogs & derivatives ; metabolism

BACKGROUND: An association has been reported between CYP2C19 polymorphism and the altered antiplatelet activity of clopidogrel. We investigated this association using the newly introduced platelet function analyzer (PFA)-200 (INNOVANCE PFA-200 System; Siemens Healthcare, Germany) P2Y test. METHODS: Polymorphisms of CYP2C19*2, *3, *17 and the degree of inhibition of platelet function were determined in 83 patients. Three different platelet function tests were used to evaluate the degree of platelet inhibition and to check the association with genotype. RESULTS: The post-procedure PFA-200 values of extensive metabolizers (EM) patients (285.3+/-38.8) were higher than those of intermediate metabolizers (IM) and poor metabolizers (PM) patients (227.7+/-98.3 and 133.7+/-99.2, respectively; P=0.024). Light transmittance aggregometry (LTA) and the VerifyNow system showed that the post-procedure values for EM patients were lower than those of IM and PM patients (LTA: 24.4+/-15.7, 34.1+/-17.6, and 42.2+/-16.9, respectively, P<0.001; VerifyNow: 133.2+/-60.5, 171.5+/-42.6, and 218.7+/-59.3, respectively, P<0.001). The high residual platelet reactivity (HPR) rates were significantly different among the EM, IM, and PM groups using PFA-200 (PM:IM:EM=82.4:40.6:11.8, P<0.001). CONCLUSIONS: Approximately, 59.0% of Korean patients with cardiovascular disease receiving clopidogrel had CYP2C19 loss-of-function genotypes classified as IM or PM, and the frequency was similar to the data from Asian people. The PFA-200, LTA, and VerifyNow platelet function tests revealed evidence of a significant association between the efficacy of clopidogrel and CYP2C19 genotypes.
Aged ; Cardiovascular Diseases/blood/*drug therapy ; Cytochrome P-450 CYP2C19/*genetics/metabolism ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Phenotype ; Platelet Aggregation Inhibitors/*therapeutic use ; Platelet Function Tests/instrumentation ; Polymorphism, Genetic ; Ticlopidine/*analogs & derivatives/therapeutic use

<p>OBJECTIVETo investigate the impact of omeprazole on platelet response to clopidogrel and the effect of polymorphisms of CYP2C19 on the antiplatelet effect of clopidogrel.p><p>METHODSPlatelet aggregation (PA) was assessed before 300 mg aspirin plus 300 mg loading dose of clopidogrel and after 300 mg aspirin plus 75 mg maintenance dose of clopidogrel 7 days later in 414 patients with acute coronary syndrome who have undergone percutaneous coronary intervention (PCI). Thereafter, gastric mucosal protective drugs were given (omeprazolem 20 mg, n=224 or cimetidine 800 mg, n=190). Fourteen days later, PA was measured again. Genotypes of CYP2C19*2 were analyzed with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).p><p>RESULTSAfter taken aspirin and clopidogrel, PA has decreased significantly in both groups. Compared with cimetidine, omeprazole had no significant impact on PA on 7 and 21 days post PCI. Compared with homozygotes or heterozygotes for the wild-type CYP2C19*2, patients with CYP2C19*2 AA genotype had significantly higher PA on 7 and 21 days post PCI (P<0.05).p><p>CONCLUSIONNo attenuating effect on platelet response to clopidogrel has been observed for Omeprazole. The variant of CYP2C19*2 AA genotype is significantly associated with attenuated response to clopidogrel.p>
Adult ; Aged ; Aryl Hydrocarbon Hydroxylases ; genetics ; metabolism ; Cytochrome P-450 CYP2C19 ; Drug Interactions ; Female ; Humans ; Male ; Middle Aged ; Omeprazole ; pharmacology ; Platelet Aggregation Inhibitors ; pharmacology ; Proton Pump Inhibitors ; pharmacology ; Ticlopidine ; analogs & derivatives ; pharmacology

<p>OBJECTIVETo investigate the frequency of CYP2C19 polymorphisms involved in clopidogrel metabolism in Fujian Han population.p><p>METHODSFrequencies of CYP2C19* 2, CYP2C19*3 and CYP2C19*17 in 1001 unrelated Fujian Han volunteers were determined with polymerase chain reaction-restriction fragment length polymorphism and direct sequencing method.p><p>RESULTSThe frequencies of CYP2C19*2, *3 and *17 were 32.4%, 5.8% and 0.4%, respectively. According to genotyping results, intermediate metabolizers (CYP2C19 *1/*2 or *1/*3) and poor metabolizers (CYP2C19 *2/*2 and *2/*3) respectively accounted for 47.95% and 13.99% of all subjects. Above frequencies were similar to those of Japan, Korea, Singapore, Malaysia, Thailand and Chinese Dai, Mongolian,Li and Hui ethnics (P>0.05), but were significantly different from those of Chinese Kazakh and Uygur ethnics, and people from Iran, Russia, Italy, Poland, Norway, Canada native Indians, Bolivia, Egypt or Tanzania (P<0.05).p><p>CONCLUSIONEthnic/regional diversity exist with regard to the prevalence of CYP2C19 polymorphisms. No significant difference were found between Fujian Han Chinese and Dai, Mongolian, Li and Hui from China or other populations from East and Southeast Asia, but higher frequencies of intermediate metabolizers and poor metabolizers compared with populations of Kazakh and Uygur in China, and people from Europe, South America and Africa.p>
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Aryl Hydrocarbon Hydroxylases ; genetics ; China ; Cytochrome P-450 CYP2C19 ; Female ; Gene Frequency ; Genotype ; Humans ; Male ; Middle Aged ; Polymorphism, Genetic ; Ticlopidine ; analogs & derivatives ; metabolism ; Young Adult

Anticonvulsants ; adverse effects ; Aryl Hydrocarbon Hydroxylases ; genetics ; Asian Continental Ancestry Group ; genetics ; Camptothecin ; analogs & derivatives ; metabolism ; Carbamazepine ; adverse effects ; Cytochrome P-450 CYP2C19 ; Glucuronosyltransferase ; genetics ; HLA-A Antigens ; genetics ; HLA-B Antigens ; genetics ; Humans ; Platelet Aggregation Inhibitors ; metabolism ; Stevens-Johnson Syndrome ; genetics ; Ticlopidine ; analogs & derivatives ; metabolism ; Topoisomerase I Inhibitors ; metabolism