Related Experiment Videos
Pharmacogenetics of β2-agonists
1Department of Pulmonary Medicine, Institute of Clinical Medicine, University of Tsukuba, Japan. nhizawa@md.tsukuba.ac.jp
Summary
Genetic variations in the β2 adrenoceptor gene (ADRB2) may influence responses to short-acting and long-acting β2-agonists for asthma and COPD. However, current genetic testing for ADRB2 polymorphisms has limited utility in predicting treatment effectiveness.
Area of Science:
- Pharmacogenetics
- Respiratory Medicine
- Genetics
Background:
- Short-acting β2-agonists (SABAs) and long-acting β2-agonists (LABAs) are crucial for managing asthma and COPD, providing bronchodilator and bronchoprotective effects.
- Controversy exists regarding β2-agonist use in asthma due to potential associations with increased mortality.
- Pharmacogenetics offers potential for personalized medicine by identifying genetically determined variations in drug response.
Purpose of the Study:
- To review the relationship between β2 adrenoceptor gene (ADRB2) polymorphisms and the efficacy of inhaled β2-agonists.
- To explore the potential of ADRB2 genotyping for predicting patient responsiveness to β2-agonist therapy.
Main Methods:
- Systematic review of studies investigating ADRB2 polymorphisms and β2-agonist response.
- Analysis of bronchodilator and bronchoprotective effects in relation to specific ADRB2 genotypes.
Main Results:
- Observed variations in patient response to SABAs and LABAs are linked to polymorphisms in the ADRB2 gene.
- Current common ADRB2 variants explain only a small fraction of the variability in treatment response.
Conclusions:
- Assessing ADRB2 genotype may offer insights into predicting chronic β2-agonist response.
- Genetic testing for ADRB2 has limited clinical utility currently due to insufficient explanation of response variation.
- Further robust clinical trials are essential for advancing pharmacogenetic approaches in β2-agonist therapy.
Related Concept Videos
01:11Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Genetic polymorphisms in drug targets have emerged as critical determinants of interindividual variability in drug response and toxicity. Pharmacogenomic investigations increasingly focus on identifying these variations to personalize and optimize therapeutic interventions. A drug target may be a receptor, enzyme, or signaling protein involved in pharmacologic responses or disease-related pathways. While early pharmacogenetic studies focused primarily on drug metabolism, current research...
01:29Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Genetic variations significantly influence drug response through pharmacokinetics, receptor interactions, and biologic milieu modifications. Pharmacokinetic alterations impact drug metabolism and clearance, affecting efficacy and toxicity. Variants in drug-metabolizing enzymes, such as CYP2C9 and CYP2C19, alter drug activation and elimination. For example, CYP2C9 loss-of-function variants require lower warfarin doses to prevent excessive bleeding, while CYP2C19 variants reduce clopidogrel...
01:27Pharmacogenetics of Drug Metabolism: Overview
Genetic polymorphism in drug metabolism is crucial to the inter-individual variability observed in drug responses. Drug metabolism primarily involves the chemical modification of drugs and other xenobiotics to enhance their elimination by increasing their polarity. Two main classes of enzymes mediate this biotransformation process: Phase I enzymes, primarily cytochrome P450s, catalyze oxidation and reduction reactions, while other enzymes, such as esterases, mediate hydrolysis, and Phase II...
01:25Antiasthma Drugs: β2-Adrenoceptor Agonists
Bronchodilators are critical in managing asthma, a chronic respiratory condition characterized by airway constriction due to inflammation and hyper-reactivity. Specifically, bronchodilators ease this constriction by relaxing the bronchial muscles, facilitating easier breathing.
One class of bronchodilators includes β2-adrenoceptor agonists. These agents target the β2-adrenoceptors located on bronchial smooth muscle cells. By stimulating these receptors, β2-agonists induce relaxation in these...
One class of bronchodilators includes β2-adrenoceptor agonists. These agents target the β2-adrenoceptors located on bronchial smooth muscle cells. By stimulating these receptors, β2-agonists induce relaxation in these...
01:27Principles of Pharmacogenetics: Types of Genetic Variants
The human genome is over 99.9% identical between individuals, yet genetic differences exist at millions of bases. The human genome contains approximately 3 million variant positions per individual, many of which are heterozygous, contributing to genetic diversity and individual traits. Genetic variations include single-nucleotide polymorphisms (SNPs), insertions, deletions, and copy number variations (CNVs).SNPs, the most common variation, involve single-base changes in DNA. These can be...
01:25Adrenergic Antagonists: Chemistry and Classification of β-Receptor Blockers
β-adrenergic antagonists, or β-blockers, modulate the sympathetic nervous system by targeting β-adrenoceptors and inhibiting catecholamine-mediated sympathetic responses. β-blockers differ in their adrenoceptor subtype affinity, lipophilicity, and α-blocking capabilities. The history of β-blocker development began with the prototype, dichloroisoprenaline, which exhibited partial agonist activity. As a result, propranolol was developed as a pure antagonist but nonselective agent, paving the way...