Association of ABCB1 polymorphisms with the efficacy of ondansetron for postoperative nausea and vomiting

CYP2D6 isoenzyme and ABCB1 gene polymorphisms associated with postoperative nausea and vomiting in women undergoing laparoscopic cholecystectomy: a randomized trial

INTRODUCTION

Postoperative nausea and vomiting is still a common complication. Serotonin receptor antagonists are commonly used in clinical practice for antiemetic prophylaxis. Interindividual variations in drug response, including single nucleotide polymorphisms, are related to pharmacokinetic and pharmacodynamic changes in these drugs and may lead to a poor therapeutic response. This study aimed to evaluate the influence of CYP2D6 isoenzyme and ABCB1 gene polymorphisms on the frequency of postoperative nausea and vomiting with the use of ondansetron or palonosetron.

METHODS

A randomized, double-blind clinical trial including 82 women aged 60 years or over undergoing laparoscopic cholecystectomy was conducted. Patients were randomized to receive either ondansetron or palonosetron for postoperative nausea and vomiting prophylaxis. DNA was extracted from saliva. Genetic polymorphisms were analyzed by real-time polymerase chain reaction. The following polymorphisms were analyzed: rs3892097 C/T, rs1128503 A/G, rs16947 A/G, rs1065852 A/G, rs1045642 A/G, rs2032582 C/A, and rs20325821 C/A.

RESULTS

Overall, vomiting, and severe nausea occurred in 22.5% and 57.5% of patients, respectively. In the palonosetron group, patients with the GG genotype (rs16947 A/G) experienced more severe nausea (p = 0.043). In the ondansetron group, patients with the AA genotype (rs16947 A/G) presented mild nausea (p = 0.034), and those with the AA genotype (rs1065852 A/G) experienced more vomiting (p = 0.034).

CONCLUSION

A low antiemetic response was observed with ondansetron in the presence of the AA genotype (rs16947 A/G) and the AA genotype (rs1065852 A/G), and a low therapeutic response was found with palonosetron in the presence of the GG genotype (rs16947 A/G) in laparoscopic cholecystectomy.

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Genome-Wide Association Study Identifies Novel Candidate Variants Associated with Postoperative Nausea and Vomiting

Considerable individual differences are widely observed in the incidence of postoperative nausea and vomiting (PONV). We conducted a genome-wide association study (GWAS) to identify potential candidate single-nucleotide polymorphisms (SNPs) that contribute to PONV by utilizing whole-genome genotyping arrays with more than 950,000 markers. The subjects were 806 patients who provided written informed consent and underwent elective surgery under general anesthesia with propofol or desflurane. The GWAS showed that two SNPs, rs2776262 and rs140703637, in the LOC100506403 and CNTN5 gene regions, respectively, were significantly associated with the frequency of nausea. In another GWAS conducted only on patients who received propofol, rs7212072 and rs12444143 SNPs in the SHISA6 and RBFOX1 gene regions, respectively, were significantly associated with the frequency of nausea as well as the rs2776262 SNP, and the rs45574836 and rs1752136 SNPs in the ATP8B3 and LOC105370198 gene regions, respectively, were significantly associated with vomiting. Among these SNPs, clinical and SNP data were available for the rs45574836 SNP in independent subjects who underwent laparoscopic gynecological surgery, and the association was replicated in these subjects. These results indicate that these SNPs could serve as markers that predict the vulnerability to PONV. Our findings may provide valuable information for achieving satisfactory prophylactic treatment for PONV.

Pharmacogenetic and clinical predictors of ondansetron failure in a diverse pediatric oncology population

PURPOSE

Chemotherapy-induced nausea and vomiting (CINV) is a frequently seen burdensome adverse event of cancer therapy. The 5-HT3 receptor antagonist ondansetron has improved the rates of CINV but, unfortunately, up to 30% of patients do not obtain satisfactory control. This study examined whether genetic variations in a relevant drug-metabolizing enzyme (CYP2D6), transporter (ABCB1), or receptor (5-HT3) were associated with ondansetron failure.

METHODS

DNA was extracted from blood and used to genotype: ABCB1 (3435C > T (rs1045642) and G2677A/T (rs2032582)), 5-HT3RB (rs3758987 T > C and rs45460698 (delAAG/dupAAG)), and CYP2D6 variants. Ondansetron failure was determined by review of the medical records and by patient-reported outcomes (PROs).

RESULTS

One hundred twenty-nine patients were approached; 103 consented. Participants were less than 1 to 33 years (mean 6.85). A total of 39.8% was female, 58.3% was White (22.3% Black, 19.4% other), and 24.3% was Hispanic. A majority had leukemia or lymphoma, and 41 (39.8%) met the definition of ondansetron failure. Of variants tested, rs45460698 independently showed a significant difference in risk of ondansetron failure between a mutant (any deletion) and normal allele (p = 0.0281, OR 2.67). Age and BMI were both predictive of ondansetron failure (age > 12 (OR 1.12, p = 0.0012) and higher BMI (OR 1.13, p = 0.0119)). In multivariate analysis, age > 12 was highly predictive of ondansetron failure (OR 7.108, p = 0.0008). rs45460698 was predictive when combined with an increased nausea phenotype variant of rs1045642 (OR 3.45, p = 0.0426).

CONCLUSION

Select phenotypes of 5-HT3RB and ABCB1, age, and potentially BMI can help predict increased risk for CINV in a diverse pediatric oncology population.

Rapid detection of single nucleotide polymorphisms using the MinION nanopore sequencer: a feasibility study for perioperative precision medicine

Introduction

Precision medicine is a phrase used to describe personalized medical care tailored to specific patients based on their clinical presentation and genetic makeup. However, despite the fact that several single nucleotide polymorphisms (SNPs) have been reported to be associated with increased susceptibility to particular anesthetic agents and the occurrence of perioperative complications, genomic profiling and thus precision medicine has not been widely applied in perioperative management.

Methods

We validated six SNP loci known to affect perioperative outcomes in Japanese patients using genomic DNA from saliva specimens and nanopore sequencing of each SNP loci to facilitate allele frequency calculations and then compared the nanopore results to those produced using the conventional dideoxy sequencing method.

Results

Nanopore sequencing reads clustered into the expected genotypes in both homozygous and heterozygous cases. In addition, the nanopore sequencing results were consistent with those obtained using conventional dideoxy sequencing and the workflow provided reliable allele frequency estimation, with a total analysis time of less than 4 h.

Conclusion

Thus, our results suggest that nanopore sequencing is a promising and versatile tool for SNP genotyping, allowing for rapid and feasible risk prediction of perioperative outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40981-022-00506-7.

Glabratephrin reverses doxorubicin resistance in triple negative breast cancer by inhibiting P-glycoprotein

Triple-negative breast cancer is one of the most aggressive breast cancer. The first therapeutic option is chemotherapy, often based on anthracycline as doxorubicin. However, chemotherapy efficacy is limited in by the presence of P-glycoprotein (Pgp), a membrane transporter protein that effluxes doxorubicin, reducing its cellular accumulation and toxicity. Inhibiting Pgp activity with effective and non-toxic products is still an open challenge. In this work, we demonstrated that the natural product Glabratephrin (Glab), a prenylated flavonoid from Tephrosia purpurea with a unique chemical structure, increased doxorubicin accumulation and cytotoxicity in triple negative breast cancer cells with high levels of Pgp, characterized by both acquired or intrinsic resistance to doxorubicin. Glab also reduced the growth of Pgp-expressing tumors, without adding significant extra-toxicities to doxorubicin treatment. Interestingly, Glab did not change the expression of Pgp, but it reduced the affinity for Pgp and the efflux of doxorubicin, as suggested by the increased Km and the reduced Vmax. In silico molecular docking predicted that Glab binds two residues (phenylalanine 322, glutamine 721) localized in the transmembrane domains of Pgp, facing the extracellular environment. Moreover, site-directed mutagenesis identified glycine 185 as a critical residue mediating the reduced catalytic efficacy of Pgp elicited by Glab. We propose Glab as an effective and safe compound able to reverse doxorubicin resistance mediated by Pgp in triple negative breast cancers, opening the way to a new combinatorial approach that may improve chemotherapy efficacy in the most refractory and aggressive breast cancer.

CHRM3 rs2165870 Polymorphism Correlates with Postoperative Nausea and Vomiting Incidence and the Efficacy of Ondansetron in a Chinese Han Population

Background

Previous GWAS studies have shown that there is a relationship between M3 muscarinic acetylcholine receptor (CHRM3) rs2165870 polymorphism and postoperative nausea and vomiting (PONV) incidence. However, no Chinese studies have addressed this issue.

Methods

To explore the relationship between CHRM3 rs2165870 polymorphism and PONV incidence in a Chinese Han population, we enrolled 512 patients receiving elective surgery in this study. CHRM3 rs2165870 polymorphism was genotyped using PCR-RFLP method.

Results

We found that AA genotype or A allele of CHRM3 rs2165870 polymorphism elevated the risk of PONV (AA versus GG; OR, 2.88; 95% CI, 1.51-5.47; P = 0.001; A versus G; OR, 1.39; 95% CI, 1.07-1.81; P = 0.013). In addition, CHRM3 rs2165870 polymorphism was related to the risk of PONV among the males, smokers, and those individuals with Apfel Score 3-4 or ASA classification 2-3. Last, we assessed the effects of CHRM3 rs2165870 polymorphism on the treatment efficacy of ondansetron for PONV. Data uncovered that 103 of 209 patients (49.3%) showed response to ondansetron treatment for PONV. The PONV incidence was significantly higher in AA genotype carriers compared with GG genotype carriers during the first 2 h after surgery, but not from 2 to 24 h after surgery.

Conclusion

To sum up, this study reveals that CHRM3 rs2165870 polymorphism is related to the incidence of PONV and treatment effects of ondansetron for preventing PONV in this Chinese Han population.

Genomics testing and personalized medicine in the preoperative setting: Can it change outcomes in postoperative pain management?

Postoperative pain and opioid use are major challenges in perioperative medicine. Pain perception and its response to opioid use are multi-faceted and include pharmacological, psychological, and genetic components. Precision medicine is a unique approach to individualized health care in which decisions in management are based on genetics, lifestyle, and environment of each person. Genetic variations can have an impact on the perception of pain and response to treatment. This can have an effect on pain management in both acute and chronic settings. Although there is currently not enough evidence for making recommendations about genetic testing to guide pain management in the acute care setting, there are some known polymorphisms that play a role in surgical pain and opioid-related postoperative adverse outcomes. In this review, we describe the potential use of pharmacogenomics (PGx) for improving perioperative pain management. We first review a number of genotypes that have shown correlations with pain and opioid use and then describe the importance of PGx-guided analgesic protocols and implementation of screening in a preoperative evaluation clinical setting.

Plasma and cerebrospinal fluid pharmacokinetics of ondansetron in humans

AIMS

Changes in serotonergic sensory modulation associated with overexpression of 5-HT₃ receptors in the central nervous system (CNS) have been implicated in the pathophysiology of neuropathic pain after peripheral nerve damage. 5-HT₃ receptor antagonists such as ondansetron can potentially alleviate neuropathic pain, but have limited effectiveness, due potentially to limited CNS access. However, there is currently limited information on CNS disposition of systemically-administered 5-HT₃ receptor antagonists. This study evaluated the cerebrospinal fluid (CSF) disposition of ondansetron, as a surrogate of CNS penetration.

METHODS

Fifteen patients were given a single 16 mg intravenous 15 minute infusion of ondansetron, followed by serial blood and a single CSF sampling. Population pharmacokinetic (PK) modelling was implemented to describe the average and individual plasma and CSF profiles of ondansetron. A two-compartmental model was used to capture ondansetron plasma PK with a single CSF compartment to describe distribution to the CNS.

RESULTS

The individual model-estimated CSF to plasma partition coefficients of ondansetron were between 0.09 and 0.20. These values were mirrored in the calculated CSF penetration ratios, ranging from 0.08 to 0.26.

CONCLUSIONS

After intravenous administration, CSF concentrations of ondansetron were approximately 7-fold lower than those observed in the plasma. A model could be developed to describe individual CSF concentration-time profiles of ondansetron based on a single CSF data point. The low CSF penetration of ondansetron may explain its limited analgesic effectiveness, and affords an opportunity to explore enhancing its CNS penetration for targeting conditions such as neuropathic pain.

New insights into the pathophysiology and risk factors for PONV

Postoperative nausea and vomiting (PONV) affects patient outcomes and satisfaction. New research has centered on evaluation of post-discharge and opioid-related nausea and vomiting. Mechanical and drug effects stimulate the release of central nervous system neurotransmitters acting at receptors in the vomiting center, area postrema, and nucleus of the solitary tract. Brain surgery has allowed insight into specific central emetogenic areas. Stimuli from peripheral organs act through afferent vagus neurons and a parasympathetic response causing nausea and vomiting. Opioids stimulate mu receptors in the chemoreceptor trigger zone and cholinergic receptors in the vestibular system. Opioids also affect gastrointestinal (GI) tract mechanics by decreasing gastric emptying, intestinal motility, GI peristalsis, and secretions. Regional blocks and non-opioid multimodal analgesia help to decrease nausea and vomiting. Patient, surgery, and anesthesia factors contribute to risk and degree of PONV experienced. Pharmacogenetics plays a role in gene typing as antiemetic medication metabolism results in varying drug effectiveness. Risk scoring systems are available. Individualized multimodal plans can be designed as part of an enhanced recovery after surgery protocol.

Genetic variability in postoperative nausea and vomiting: A systematic review

BACKGROUND

Postoperative nausea and vomiting (PONV) is the most frequent side effect following anaesthesia. Predisposition to developing PONV is multifactorial with patient risk factors and anaesthetic techniques both being contributory. However, there is also a genetic susceptibility to PONV, and several studies have aimed to identify polymorphisms contributing to a genetic PONV risk.

OBJECTIVE

We summarised previous published studies investigating genetic contribution to PONV risk.

DESIGN

Systematic review without meta-analysis.

DATA SOURCE

We searched MEDLINE until June 2019.

ELIGIBILITY CRITERIA

Articles were chosen for review when PONV and polymorphisms were included. Exclusion criteria were reviews/meta-analysis/comments, articles not in the English language, nonappropriate content (e.g. PONV not as primary aim of the study, study investigated opioid-induced nausea) or if articles were pharmacogenetic studies addressing treatment of PONV.

RESULTS

A total of 59 studies were screened and 14 articles were reviewed including one genome-wide association study (GWAS). Seven studies were performed in East Asians, and seven in Caucasians. Seventeen polymorphisms have been positively associated with PONV in at least one study. Allele frequency of the investigated polymorphisms differs widely between the ethnicities. Furthermore, the anaesthesia regimen and the postoperative time point at which the association with PONV was reported were quite different. Only two polymorphisms, the CHRM3 rs2165870 and the KCNB2 rs349358 (both first associated with PONV in a GWAS), have been significantly associated with PONV incidence in Caucasians in independent studies.

CONCLUSION

There is a genetic susceptibility to the development of PONV. Two single nucleotide polymorphisms (SNPs), the CHRM3 rs2165870 and the KCNB2 rs349358 SNP, seem to have a major influence on PONV incidence, at least in Caucasians. Both SNPs were primarily identified in a GWAS and this association may lead to a better understanding of the disease aetiology. Further high-quality studies are needed to reveal more insights in genetic PONV susceptibility, particularly so in non-Caucasian ethnicities.

Pharmacogenetics of Postoperative Nausea and Vomiting

Postoperative nausea and vomiting (PONV) remains one of the most common adverse effects of anesthesia, affecting up to 80% of high-risk patients within 24 hours after surgery. Patient-related factors, surgical procedure, and perioperative medications such as opioids determine a patient's risk for PONV. To prevent and manage PONV, ondansetron, a 5-hydroxytryptamine type 3 (5-HT₃) receptor antagonist, is frequently administered. Ondansetron is metabolized predominantly by hepatic cytochrome P450 (CYP2D6) enzymes, encoded by the CYP2D6 gene, whereas most of the effects of opioids are exerted at the opioid mu-1 receptor, encoded by the OPRM1 gene. Genetic polymorphisms of the CYP2D6 and OPRM1 genes may have a role in interindividual variation in the occurrence of PONV. Specifically, the occurrence of the G-allele produced by the OPRM1 A118G appears to be protective against PONV, whereas CYP2D6 ultrarapid metabolism increases the risk for PONV. The Clinical Pharmacogenetics Implementation Consortium guidelines provide CYP2D6-guided therapeutic recommendations for ondansetron. However, further studies are needed to investigate the role of genetic polymorphism in the occurrence of PONV and response to antiemetics.

ATP-Binding Cassette Transporters in the Clinical Implementation of Pharmacogenetics

ATP-binding cassette (ABC) transporters are involved in a large number of processes and contribute to various human genetic diseases. Among other functions, ABC proteins are involved in the transport of multiple drugs through cells. Most of the genes coding for these transporters are highly polymorphic and DNA variants in these genes can affect the normal functioning of these proteins, affecting the way drugs are transported, increasing or decreasing drug levels. These changes in the intracellular and extracellular drug levels may be associated with altered drug effectiveness or severe drug-induced adverse events. This review presents a state-of-art of the most pharmacogenetics clinically relevant ABC transporters closed to the clinical implementation.

Genetic Factors Associated with Postoperative Nausea and Vomiting: a Systematic Review

BACKGROUND

In previous studies, there seems to be a relationship between different genetic polymorphisms and postoperative nausea and vomiting (PONV). We perform a systematic review of the current literature about the relationship between genetic polymorphisms and the presence of PONV.

METHODS

Two bibliographic searches were carried out in three databases (PubMed, Web of Science, and Scopus) of studies, preferably prospective, about PONV following abdominal surgery. It was completed with a backward citation searching. A total of 73 articles were found of which 6 were selected after their critical lecture using CASPe network criteria. Relative frequency and relative risk were taken in each study according to the polymorphism.

RESULTS

Studies about 5-HT3B gene receptor polymorphisms, ABCB1 transporter, and dopamine D2 receptor showed a significant association with the presence of PONV (p = 0.02, 0.01, and 0.034 respectively). In relation to cytochrome P-450 2D6 (CYP2D6) polymorphisms, two of the three analysed articles showed a significant association with postoperative vomiting (p = 0.007).

CONCLUSION

Genetic polymorphisms could play an important role in PONV. The AAG deletion in both alleles of the 5-HT3B receptor gene, the Taq IA polymorphism of the dopamine D2 receptor, and the presence of three or more functional alleles of CYP2D6 seem to be related with a higher incidence of PONV, especially in the first 24 h after surgery. The 2677TT and 3435TT genotypes of the ABCB1 transporter could reduce the PONV due to their association with a greater effectiveness of ondansetron. However, new quality studies are needed to consider this relationship.

Combination of dihydromyricetin and ondansetron strengthens antiproliferative efficiency of adriamycin in K562/ADR through downregulation of SORCIN: A new strategy of inhibiting P-glycoprotein

Though the advancement of chemotherapy drugs alleviates the progress of cancer, long-term therapy with anticancer agents gradually leads to acquired multidrug resistance (MDR), which limits the survival outcomes in patients. It was shown that dihydromyricetin (DMY) could partly reverse MDR by suppressing P-glycoprotein (P-gp) and soluble resistance-related calcium-binding protein (SORCIN) independently. To reverse MDR more effectively, a new strategy was raised, that is, circumventing MDR by the coadministration of DMY and ondansetron (OND), a common antiemetic drug, during cancer chemotherapy. Meanwhile, the interior relation between P-gp and SORCIN was also revealed. The combination of DMY and OND strongly enhanced antiproliferative efficiency of adriamycin (ADR) because of the increasing accumulation of ADR in K562/ADR-resistant cell line. DMY could downregulate the expression of SORCIN and P-gp via the ERK/Akt pathways, whereas OND could not. In addition, it was proved that SORCIN suppressed ERK and Akt to inhibit P-gp by the silence of SORCIN, however, not vice versa. Finally, the combination of DMY, OND, and ADR led to G2/M cell cycle arrest and apoptosis via resuming P53 function and restraining relevant proteins expression. These fundamental findings provided a promising approach for further treatment of MDR.

Effects of Single Nucleotide Polymorphisms on Surgical and Postsurgical Opioid Requirements: A Systematic Review and Meta-Analysis

OBJECTIVES

There is great heterogeneity in the way individuals respond to medications. Inherited differences, such as single nucleotide polymorphisms (SNP), can influence the efficacy and toxicity of drugs. This meta-analysis aims to collate data from studies investigating the effect of SNPs on postoperative and/or intraoperative opioid requirements.

MATERIALS AND METHODS

A meta-analysis was conducted following PRISMA guidelines. Eligibility criteria for studies included were reporting amount of postoperative and/or intraoperative opioid used as the primary outcome and genotyping patients for SNPs in one of the following genes; OPRM1, CYP2D6, CYP3A4, CYP3A5, COMT, UGT2B7, or ABCB1. A comprehensive systematic search for articles using keywords "opioid-sensitivity," "polymorphisms," "post-operative opioid," "post-surgical opioid," "post-operative pain," and "post-surgical pain" was performed.

RESULTS

Fifty-one studies were included. Individuals homozygous for AA at the OPRMI (rs1799971) polymorphisms required less postsurgical opioid compared with those homozygous for GG (Hedges g, -0.270; 95% confidence interval, -0.433 to -0.108; P=0.001). Polymorphisms in CYP2D6, CYP3A4, CYP3A5, COMT, UGT2B7, and ABCB1 did not affect opioid requirements.

DISCUSSION

Investigation of single changes in 1 gene can only yield limited information regarding genetic effects on opioid requirements. Rapid development of whole genome sequencing enables information on all genetic modifications that may affect analgesic response to be collected. The information collected must include data on the individual's metabolic enzymes, as well as information on drug receptors and enzymes responsible for drug degradation, so that a personal profile can be built up which will predict individual response to drugs, and guide clinicians on the type and dosage of drug to use.

Correlation of MDR1 gene polymorphism with propofol combined with remifentanil anesthesia in pediatric tonsillectomy

The motive of this study was to investigate the interaction between polymorphisms in the MDR1 gene and anesthetic effects following pediatric tonsillectomy. In total, 240 children undergoing tonsillectomy with preoperative propofol-remifentanil anesthesia were selected. Genomic DNA was extracted from the peripheral blood of children after operation, and the MDR1 gene polymorphisms of 2677 G>T/A, 1236 C>T and 3435 C>T were detected by direct sequencing. We tested mean arterial pressure, diastolic blood pressure, systolic blood pressure, and heart rate at several time-points: T0 (5 mins after the repose), T1 (0 min after tracheal intubation), T2 (5 mins after the tracheal intubation), T3 (0 min after the tonsillectomy), T4 (0 min after removal of the mouth-gag) and T5 (5 min after the extubation). The visual analog scale, the face, legs, activity, cry, and consolability pain assessment, and the Ramsay sedation score were recorded after the patients regained consciousness. Adverse reactions were also recorded. The time of induction, respiration recovery, eye-opening, and extubation of children with the CC genotype were found to be shorter compared to the CT + TT genotype of MDR1 1236C > T (all P <.05). The mean arterial pressure, diastolic blood pressure, systolic blood pressure, and heart rate were significantly reduced at T5 in children with the CC genotype (all P <.05). The visual analog scale at 1, 2, 4, and 8 hours post-operation, and the Ramsay sedation score at 5, 10, and 30 min after the extubation were decreased, while the face, legs, activity, cry, and consolability pain assessment score increased (all P <0.05). There was no statistically significant difference in the adverse reaction of MDR1 mutations (P> 0.05). It could be concluded that anesthetic effect following pediatric tonsillectomy in patients with the MDR1 1236C > T CC genotype was stronger than in those carrying the CT + TT genotype.

Renal Drug Transporters and Drug Interactions

Transporters in proximal renal tubules contribute to the disposition of numerous drugs. Furthermore, the molecular mechanisms of tubular secretion have been progressively elucidated during the past decades. Organic anions tend to be secreted by the transport proteins OAT1, OAT3 and OATP4C1 on the basolateral side of tubular cells, and multidrug resistance protein (MRP) 2, MRP4, OATP1A2 and breast cancer resistance protein (BCRP) on the apical side. Organic cations are secreted by organic cation transporter (OCT) 2 on the basolateral side, and multidrug and toxic compound extrusion (MATE) proteins MATE1, MATE2/2-K, P-glycoprotein, organic cation and carnitine transporter (OCTN) 1 and OCTN2 on the apical side. Significant drug-drug interactions (DDIs) may affect any of these transporters, altering the clearance and, consequently, the efficacy and/or toxicity of substrate drugs. Interactions at the level of basolateral transporters typically decrease the clearance of the victim drug, causing higher systemic exposure. Interactions at the apical level can also lower drug clearance, but may be associated with higher renal toxicity, due to intracellular accumulation. Whereas the importance of glomerular filtration in drug disposition is largely appreciated among clinicians, DDIs involving renal transporters are less well recognized. This review summarizes current knowledge on the roles, quantitative importance and clinical relevance of these transporters in drug therapy. It proposes an approach based on substrate-inhibitor associations for predicting potential tubular-based DDIs and preventing their adverse consequences. We provide a comprehensive list of known drug interactions with renally-expressed transporters. While many of these interactions have limited clinical consequences, some involving high-risk drugs (e.g. methotrexate) definitely deserve the attention of prescribers.

Correlation of MDR1 gene polymorphisms with anesthetic effect of sevoflurane-remifentanil following pediatric tonsillectomy

BACKGROUND

The motive of this study was to investigate the collaboration between MDR1 gene polymorphisms and anesthetic effects following pediatric tonsillectomy.

METHODS

All together 178 children undergoing tonsillectomy with preoperative sevoflurane-remifentanil anesthesia were selected. In order to determine MDR1 gene polymorphisms of 3435C > T, 1236C > T, and 2677G > T/A, polymerase chain reaction-restriction fragment length polymorphism was used. Mean arterial pressure (MAP), diastolic blood pressure (DBP), systolic blood pressure (SBP), and heart rate (HR) at T0 (5 mins after the repose), T1 (0 min after tracheal intubation), T2 (5 mins after the tracheal intubation), T3 (0 min after the tonsillectomy), T4 (0 min after removal of the mouth-gag) and T5 (5 min after the extubation) were observed. The visual analog scale (VAS), the face, legs, activity, cry, and consolability (FLACC) pain assessment, and Ramsay sedation score were recorded after the patients gained consciousness. The adverse reactions were also observed.

RESULTS

As compared to the CT + TT genotype of MDR1 1236C > T, the time of induction, respiration recovery, eye-opening, and extubation of children with the CC genotype was found to be shorter (all P <.05); the MAP, SBP, DBP, and HR were significantly reduced at T5 in children that possessed the CC genotype (all P <.05), the VAS at postoperative 1, 2, 4, and 8 hours and Ramsay sedation score were decreased, while the FLACC score increased (all P <.05). It was found that the adverse reaction rate was lower in children bearing the CC genotype (P <.05).

CONCLUSION

It could be concluded that anesthetic effect in patients with the MDR1 1236C > T CC genotype was found to be superior to those carrying the CT + TT genotype.

Influence of ABCB1 and ABCG2 polymorphisms on the antiemetic efficacy in patients with cancer receiving cisplatin-based chemotherapy: a TRIPLE pharmacogenomics study

Resistance to antiemetic treatment with 5-hydroxytryptamine-3 receptor antagonist is an issue. This study evaluated the potential roles of ABCB1 and ABCG2 polymorphisms in antiemetic treatment resistance in patients with cancer previously enrolled in a randomized controlled trial. A total of 156 patients were evaluated for their responses to antiemetic therapy and then subdivided into granisetron or palonosetron groups. The genotypes were evaluated for their association with antiemetic efficacy in each treatment groups. Additional risk factors associated with complete response (CR) were examined using a multivariate regression analysis. No significant associations were identified for genetic polymorphisms in the palonosetron group. In the granisetron group, patients with ABCB1 2677TT and 3435TT genotypes had higher proportion of CR. In addition to ABCB1 polymorphisms, gender and cisplatin dose were associated with granisetron response by univariate analysis. Multivariate logistic regression analysis revealed that the ABCB1 3435C>T polymorphism and cisplatin dose were significant predictors of CR.

Data, Big Data, and Metadata in Anesthesiology

The last decade has seen an explosion in the growth of digital data. Since 2005, the total amount of digital data created or replicated on all platforms and devices has been doubling every 2 years, from an estimated 132 exabytes (132 billion gigabytes) in 2005 to 4.4 zettabytes (4.4 trillion gigabytes) in 2013, and a projected 44 zettabytes (44 trillion gigabytes) in 2020. This growth has been driven in large part by the rise of social media along with more powerful and connected mobile devices, with an estimated 75% of information in the digital universe generated by individuals rather than entities. Transactions and communications including payments, instant messages, Web searches, social media updates, and online posts are all becoming part of a vast pool of data that live "in the cloud" on clusters of servers located in remote data centers. The amount of accumulating data has become so large that it has given rise to the term Big Data. In many ways, Big Data is just a buzzword, a phrase that is often misunderstood and misused to describe any sort of data, no matter the size or complexity. However, there is truth to the assertion that some data sets truly require new management and analysis techniques.

Association of 5-HT3B Receptor Gene Polymorphisms with the Efficacy of Ondansetron for Postoperative Nausea and Vomiting

PURPOSE

Postoperative nausea and vomiting (PONV) is a common problem after general anesthesia. Although 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists have significantly reduced PONV, over 35% of patients treated with ondansetron can experience PONV. In this study, we investigated whether the Y129S and -100_-102AAG deletion polymorphisms of the 5-HT3B receptor gene affect the efficacy of ondansetron in preventing PONV.

MATERIALS AND METHODS

Two hundred and forty-five adult patients who underwent laparoscopic cholecystectomy were enrolled. Ondansetron 0.1 mg/kg was intravenously administered 30 minutes before the end of surgery. Genomic DNA was prepared from blood samples using a nucleic acid isolation device. Both the Y129S variant and the -100_-102AAG deletion variant were screened for using a single base primer extension assay and a DNA direct sequencing method, respectively. The relationship between genetic polymorphisms and clinical outcomes of ondansetron treatment was investigated.

RESULTS

Among the 5-HT3B AAG deletion genotypes, the incidence of PONV was higher in patients with the homomutant than with other genotypes during the first 2 hours after surgery (p=0.02). There were no significant differences in the incidence of PONV among genotypes at 2-24 hours after surgery. In the Y129S variants of the 5-HT3B receptor gene, there were no significant differences in the incidence of PONV among genotypes during the first 2 hours and at 2-24 hours after surgery.

CONCLUSION

The response to ondansetron for PONV was significantly influenced by the -100_-102AAG deletion polymorphisms of the 5-HT3B gene. Thus, the -100_-102AAG deletion variants may be a pharmacogenetic predictor for responsiveness to ondansetron for PONV.

Postoperative nausea and vomiting

Postoperative nausea and vomiting (PONV) is a long-standing issue, not a new concept in anesthesiology. Despite many studies over the last several decades, PONV remains a significant problem due to its complex mechanism. This review presents a summary of the mechanism underlying the pathogenesis of PONV, focusing on preventive treatment, particularly the use of new drugs. In addition, we discuss the latest meta-analysis results regarding correct clinical use of classic drugs. I also summarize the latest trends of postdischarge nausea and vomiting and the pharmacogenetics, which is attracting a great deal of attention from other medical fields in PONV-related studies. Finally, we discuss the drawbacks of existing studies on PONV and suggest a focus for future investigations.

Genetic factors associated with pharmacotherapy and background sensitivity to postoperative and chemotherapy-induced nausea and vomiting

Postoperative nausea and vomiting (PONV) continues to be a most common complication of surgery and anesthesia. It has been suggested that the inherited factors may play a significant role in the background sensitivity to both PONV and also chemotherapy-induced nausea and vomiting (CINV), including resistance to antiemetic prophylaxis and/or therapy. This notion could be best exemplified by occurrence of PONV in several generations of families and concordance of PONV in monozygotic twins. The most frequently addressed issue in the research on genomic background of PONV/CINV relates to the inherited resistance to the antiemetic treatment (pharmacogenomics), and in lesser degree to their genomic background. The most common group of antiemetics consists of 5HT3 receptor antagonists, and this group was an initial target of pharmacogenomic research. Most research approaches have been based on the investigation of polymorphic variations in the target for the antiemetic 5HT3 receptor antagonists, i.e., serotonin receptor subunits A and B (HTR3A and HTR3B). The other area of pharmacogenomic investigations includes metabolic pathways of 5HT3 antagonists, in particular polymorphic variants of the CYP450 2D6 isoform (CYP2D6) because most of them are metabolized in various degrees by the CYP2D6 system. The results of targeted genomic association studies indicate that other genes are also associated with PONV and CINV, including OPRM1, and ABCB1. In addition, genes such as DRD2 and CHRM3 genes have recently been associated with PONV. The new genome-wide association studies seem also to indicate that the background genomic sensitivity to PONV and CINV might be multifactorial and include several genomic pathways.

Pathophysiological and neurochemical mechanisms of postoperative nausea and vomiting

Clinical research shows that postoperative nausea and vomiting (PONV) is caused primarily by the use of inhalational anesthesia and opioid analgesics. PONV is also increased by several risk predictors, including a young age, female sex, lack of smoking, and a history of motion sickness. Genetic studies are beginning to shed light on the variability in patient experiences of PONV by assessing polymorphisms of gene targets known to play roles in emesis (serotonin type 3, 5-HT3; opioid; muscarinic; and dopamine type 2, D2, receptors) and the metabolism of antiemetic drugs (e.g., ondansetron). Significant numbers of clinical trials have produced valuable information on pharmacological targets important for controlling PONV (e.g., 5-HT3 and D2), leading to the current multi-modal approach to inhibit multiple sites in this complex neural system. Despite these significant advances, there is still a lack of fundamental knowledge of the mechanisms that drive the hindbrain central pattern generator (emesis) and forebrain pathways (nausea) that produce PONV, particularly the responses to inhalational anesthesia. This gap in knowledge has limited the development of novel effective therapies of PONV. The current review presents the state of knowledge on the biological mechanisms responsible for PONV, summarizing both preclinical and clinical evidence. Finally, potential ways to advance the research of PONV and more recent developments on the study of postdischarge nausea and vomiting (PDNV) are discussed.

Functional significance of genetic polymorphisms in P-glycoprotein (MDR1, ABCB1) and breast cancer resistance protein (BCRP, ABCG2)

Recent pharmacogenomic/pharmacogenetic (PGx) studies have disclosed important roles for drug transporters in the human body. Changes in the functions of drug transporters due to drug/food interactions or genetic polymorphisms, for example, are associated with large changes in pharmacokinetic (PK) profiles of substrate drugs, leading to changes in drug response and side effects. This information is extremely useful not only for drug development but also for individualized treatment. Among drug transporters, the ATP-binding cassette (ABC) transporters are expressed in most tissues in humans, and play protective roles; reducing drug absorption from the gastrointestinal tract, enhancing drug elimination into bile and urine, and impeding the entry of drugs into the central nervous system and placenta. In addition to PK/pharmacodynamic (PD) issues, ABC transporters are reported as etiologic and prognostic factors (or biomarkers) for genetic disorders. Although a consensus has not yet been reached, clinical studies have demonstrated that the PGx of ABC transporters influences the overall outcome of pharmacotherapy and contributes to the pathogenesis and progression of certain disorders. This review explains the impact of PGx in ABC transporters in terms of PK/PD, focusing on P-glycoprotein and breast cancer resistance protein (BCRP).