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Julie A Johnson

Publications and source records attributed to Julie A Johnson.

At least 19 recordsLinked to original sources
PubMed2026

Genotype-Guided Antidepressant Prescribing for Patients With Depression: A Randomized Clinical Trial.

IMPORTANCE: The effectiveness of pharmacogenetics to guide prescribing of selective serotonin reuptake inhibitors (SSRIs) for depression remains unclear, despite the well-established association between SSRI pharmacokinetics and genetic variation. OBJECTIVE: To determine whether pharmacogenetic-guided prescribing of SSRIs improves treatment response in patients with depression. DESIGN, SETTING, AND PARTICIPANTS: The ADOPT PGx (A Depression and Opioid Pragmatic Trial in Pharmacogenetics) Depression pragmatic randomized clinical trial was conducted from August 10, 2021, through April 27, 2024, at primary care, psychiatry, or family medicine clinics at enrolling sites throughout the US. Patients were aged 8 years or older and had experienced depression for 3 months or longer. INTERVENTION: Patients were randomized to genotype-guided SSRI prescribing (intervention group) or usual care (control group). Actionable drug metabolism phenotypes were defined as those for which pharmacogenetic clinical guidelines recommend alternative medication selection or dose adjustment. MAIN OUTCOMES AND MEASURES: The primary outcome was change in Patient-Reported Outcomes Measurement Information System (PROMIS) depression T scores at 3 months among patients with the actionable phenotype. Secondary end points included adverse effect severity of SSRIs at 3 months and depression remission (measured with PROMIS depression scores and Patient Health Questionnaire-8 [PHQ-8] scores) at 6 months. RESULTS: This study of 1460 patients included 1239 adults (84.9%) (mean [SD] age, 40.6 [16.7] years) and 221 children (15.1%) (mean [SD] age, 14.6 [1.8] years). Most patients were female (1096 [75.1%]). A total of 692 patients (47.4%) had an actionable phenotype; 351 (50.7%) were assigned to the intervention, and 341 (49.3%) were assigned to usual care. At baseline, 463 of the 692 patients (66.9%) reported having depressive symptoms for more than 2 years, 603 (87.1%) were receiving pharmacologic treatment, and 354 (51.2%) were receiving nonpharmacologic treatment. At 3 months, no significant differences were observed between the intervention and usual care groups in change in PROMIS depression T scores (mean [SD] change, -4.3 [8.4] vs -4.0 [8.1]; P = .68), medication adverse effect burden (mean [SD] change, 8.2 [4.3] vs 7.8 [4.5]; P = .37), or Patient Health Questionnaire-8 score change (mean [SD] change, -3.3 [5.2] vs -2.7 [4.8]; P  = .13). However, at 6 months, the PROMIS depression T-score remission rate (score ≤16) was higher in the intervention group compared with the usual care group (153 of 317 patients [48.3%] vs 122 of 310 patients [39.4%]; P = .02). CONCLUSIONS AND RELEVANCE: In this randomized clinical trial, genotype-guided prescribing of SSRIs did not improve control of depression symptoms at 3 months compared with usual care but was associated with higher depression remission rates at 6 months. These findings suggest a possible longer-term clinical benefit and indicate that future studies should focus on the durability and long-term impact of genotype-guided prescribing in the management of depressive symptoms. TRIAL REGISTRATION: ClinicalTrials.gov Identifiers: NCT04445792 (Master Protocol Research Program platform trial) and NCT05966155 (ADOPT PGx Depression trial).

Humans↗
PubMed2006

Relation of beta(2)-adrenoceptor haplotype to risk of death and heart transplantation in patients with heart failure.

Heart failure (HF) is characterized by neurohormonal activation of the sympathetic nervous and renin-angiotensin systems. Genetic polymorphisms in these systems could alter the prognosis in HF. We hypothesized the genetic polymorphisms in the sympathetic nervous and renin-angiotensin systems are associated with adverse outcomes, defined as death or heart transplantation in patients with HF. A total of 227 patients with HF were enrolled from a tertiary care clinic and followed for outcomes for < or =4 years. Eight polymorphisms in 6 genes were genotyped: beta(1)-adrenergic receptor (ADRB1, S49G, R389G), beta(2)-adrenergic receptor (ADRB2, G16R, Q27E), alpha(2c)-adrenergic receptor (ADRA2C, insertion/deletion 322-325), angiotensinogen (AGT, M235T), angiotensin receptor type 1 (AGTR1, 1166A>C), and angiotensin-converting enzyme (ACE, insertion/deletion in intron 16). Most patients were treated according to consensus guidelines. Male gender (hazard ratio 2.24, 95% confidence interval 1.27 to 3.94), higher New York Heart Association functional class (hazard ratio 2.54, 95% confidence interval 1.84 to 3.52), and 2 copies of ADRB2 Arg16Gln27 haplotype (hazard ratio 1.91, 95% confidence interval 1.09 to 3.36) increased the risk of adverse outcomes. In contrast, a higher serum sodium level (hazard ratio 0.91, 95% confidence interval 0.86 to 0.97) and higher creatinine clearance (hazard ratio 0.99, 95% confidence interval 0.98 to 0.99) decreased the risk of adverse outcomes. None of the other genotypes/haplotypes were associated with adverse outcomes. In conclusion, ADRB2 Arg16Gln27 haplotype may significantly increase the risk of adverse outcomes in patients with HF receiving contemporary HF pharmacotherapy.

DNA↗
PubMed2006

Pharmacogenomics: challenges and opportunities.

The outcome of drug therapy is often unpredictable, ranging from beneficial effects to lack of efficacy to serious adverse effects. Variations in single genes are 1 well-recognized cause of such unpredictability, defining the field of pharmacogenetics (see Glossary). Such variations may involve genes controlling drug metabolism, drug transport, disease susceptibility, or drug targets. The sequencing of the human genome and the cataloguing of variants across human genomes are the enabling resources for the nascent field of pharmacogenomics (see Glossary), which tests the idea that genomic variability underlies variability in drug responses. However, there are many challenges that must be overcome to apply rapidly accumulating genomic information to understand variable drug responses, including defining candidate genes and pathways; relating disease genes to drug response genes; precisely defining drug response phenotypes; and addressing analytic, ethical, and technological issues involved in generation and management of large drug response data sets. Overcoming these challenges holds the promise of improving new drug development and ultimately individualizing the selection of appropriate drugs and dosages for individual patients.

Clinical Medicine↗
PubMed2006

Influence of coagulation factor, vitamin K epoxide reductase complex subunit 1, and cytochrome P450 2C9 gene polymorphisms on warfarin dose requirements.

INTRODUCTION: The primary objective of this study was to determine whether variability in warfarin dose requirements is determined by common polymorphisms in genes whose products are involved in the pharmacodynamics and pharmacokinetics of warfarin, namely, the coagulation factors, vitamin K epoxide reductase complex subunit 1 (VKORC1), and cytochrome P450 (CYP) 2C9. METHODS: Patients (N = 350) receiving stable doses of warfarin at 3 consecutive visits were enrolled, and a deoxyribonucleic acid sample was collected. Samples were genotyped for polymorphisms in the factor II, factor VII, factor X, VKORC1, and CYP2C9 genes. A stepwise linear regression analysis was used to determine the independent effects of genetic and nongenetic factors on mean warfarin dose requirements. RESULTS: Variables associated with lower warfarin dose requirements were VKORC1 3673 AA genotype (P < .0001), VKORC1 3673 GA genotype (P < .0001), 1 variant CYP2C9 allele (P < .0001), 2 variant CYP2C9 alleles (P = .0004), increasing age (P = .0005), concomitant CYP2C9 inhibitors (P = .0005), and goal international normalized ratio (P = .01). Variables associated with higher warfarin dose requirements were weight (P < .0001), current smoker status (P = .0009), mean international normalized ratio (P = .001), concomitant CYP2C9 inducers (P = .006), factor X insertion/deletion genotype (P = .01), factor X insertion/insertion genotype (P = .04), factor VII deletion/deletion genotype (P = .04), and calculated vitamin K intake (P = .05). The linear regression model explained 51.4% of the variability in warfarin dose requirements. CONCLUSION: Polymorphisms in warfarin drug target and metabolizing enzyme genes, in addition to nongenetic factors, were important determinants of warfarin dose requirements.

Adult↗
PubMed2006

Sustained restoration of autonomic balance with long- but not short-acting metoprolol in patients with heart failure.

BACKGROUND: The purpose of this study was to compare the effects of immediate-release (IR) metoprolol and extended-release (XL) metoprolol on measures of heart rate variability in chronic systolic heart failure patients. METHODS AND RESULTS: Thirteen metoprolol-treated heart failure patients were randomized to a 2-way crossover study of equal daily doses of metoprolol IR and metoprolol XL, each administered for 3 weeks. After each 3-week interval, patients underwent 24-hour Holter and ambulatory blood pressure monitoring. Over the entire 24-hour period, the ratio of high to total variability (normalized measure of parasympathetic activity) was significantly greater (P < .05), the ratio of low to total variability (normalized measure of sympathetic activity) was significantly lower (P < .05), and the ratio of high to low variability (index of parasympathetic to sympathetic balance) was greater (P < .08) for metoprolol XL compared with metoprolol IR. Over the entire 24-hour period, both systolic and diastolic blood pressure were significantly lower for metoprolol XL compared with metoprolol IR (P < .0001, and .0005, respectively). CONCLUSION: These data suggest that with twice daily dosing, metoprolol IR is inferior to metoprolol XL in its effects on heart rate variability, autonomic balance, and blood pressure in patients with heart failure.

Adrenergic beta-Antagonists↗
PubMed2006

Highly variable mRNA expression and splicing of L-type voltage-dependent calcium channel alpha subunit 1C in human heart tissues.

OBJECTIVES: The voltage-dependent L-type calcium channel alpha-subunit 1c (Cav1.2, CACNA1C) undergoes extensive mRNA splicing, leading to numerous isoforms with different functions. L-type calcium channel blockers are used in the treatment of hypertension and arrhythmias, but response varies between individuals. We have studied the interindividual variability in mRNA expression and splicing of CACNA1C, in 65 heart tissue samples, taken from heart transplant recipients. METHODS: Splice variants were measured quantitatively by polymerase chain reaction in 12 splicing loci of CACNA1C mRNA. To search for functional cis-acting polymorphisms, we determined allelic expression ratios for total CACNA1C mRNA and several splice variants using marker single nucleotide polymorphisms in exon 4 and exon 30. RESULTS: Total CACNA1C mRNA levels varied approximately 50-fold. Substantial splicing occurred in six loci generating two or more splice variants, some with known functional differences. Splice patterns varied broadly between individuals. Two heart tissues expressed predominantly the dihydropyridine-sensitive smooth muscle isoform of CACNA1C (containing exon 8), rather than the cardiac isoform (containing exon 8a). Lack of significant allelic expression imbalance, observed with total mRNA and several splice variants, argued against CACNA1C polymorphisms as a cause of variability. Taken together, highly variable splicing can cause profound phenotypic variations of CACNA1C function, potentially associated with disease susceptibility and response to L-type calcium channel blockers.

Alleles↗
PubMed2006

Pharmacogenetics of chronic cardiovascular drugs: applications and implications.

Cardiovascular disease continues to be a tremendous worldwide problem, and drug therapy is a major modality to attenuate its burden. At present, conditions such as hypertension, dyslipidaemia and heart failure are pharmacologically managed with an empirical trial-and-error approach. However, it has been suggested that this approach fails to adequately address the therapeutic needs of many patients, and pharmacogenetics has been offered as a tool to enhance patient-specific drug therapy. This review outlines pharmacogenetic studies of common cardiovascular drugs, such as diuretics, beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, statins and warfarin, ultimately highlighting considerations for future research and practice.

Anticoagulants↗
PubMed2006

Discordant beta-blocker effects on clinic, ambulatory, resting, and exercise hemodynamics in patients with hypertension.

STUDY OBJECTIVES: To determine the correlation between ambulatory and clinic blood pressure in assessing antihypertensive response to beta-blockade, to test whether blood pressure response to metoprolol is associated with the heart rate response, and to determine whether exercise and resting heart rate responses to metoprolol are correlated. DESIGN: Post hoc analysis of a prospective cohort study. SETTING: University-affiliated general clinical research center. PATIENTS: Fifty-one patients aged 35-65 years with uncomplicated hypertension. Intervention. All patients received metoprolol at a dosage titrated to achieve a diastolic blood pressure below 90 mm Hg. MEASUREMENTS AND MAIN RESULTS: Clinic and 24-hour ambulatory blood pressure measurements were obtained and exercise treadmill testing was performed before and after metoprolol treatment. Based on ambulatory blood pressure data, 24 patients (47%) responded (defined as at least a 10% reduction in diastolic blood pressure) to metoprolol compared with 36 patients (71%) based on clinic blood pressure data (p=0.027). Clinic blood pressure was associated with a 67% false-positive rate (responsive blood pressure by clinic data that was actually nonresponsive by ambulatory data). Blood pressure responders and nonresponders exhibited similar reductions in exercise heart rate (24% and 23%, p=0.74). However, responses to metoprolol measured by exercise heart rate versus resting heart rate were not significantly correlated (r=0.24, p=0.105). CONCLUSION: Reliance on clinic blood pressure or resting heart rate for making beta-blocker treatment decisions may yield less than optimal assessment of the antihypertensive response or degree of beta-blockade.

Adrenergic beta-Antagonists↗
PubMed2005

Cardiovascular pharmacogenomics.

There is large interpatient variability in the response to drugs, including cardiovascular drugs. Thus, while some patients achieve the desired therapeutic response from their drug therapy, others do not. There is also a subset of patients who will experience adverse effects, which can range from bothersome to life threatening. Research in recent years has provided compelling evidence that in many cases, genetics contributes importantly to this variable drug response. Thus, pharmacogenomics is a field focused on unravelling the genetic determinants of variable drug response. Examples from the literature of genetic associations with drug efficacy and toxicity are described to provide insight into the field, including the roles of genetic variability in drug-metabolizing enzymes and drug targets. There is also a detailed discussion of the experimental approaches used in cardiovascular pharmacogenomics. Current research is largely focused on a limited candidate gene approach, which allows for description of significant genetic associations with variable response, but often does not explain the genetic basis of variable drug response enough to be useful clinically. As such, there is a move towards genome-wide approaches, and the various technologies available to obtain genomic data are discussed. Cardiovascular pharmacogenomics has the potential for leading to improvements in the use of cardiovascular drug therapy, through selection of the most appropriate drug therapy in an individual based on their genetic information. It will probably be a decade or more before genetic information is widely used in drug therapy decisions, but it seems clear that important findings in the area will continue to expand and the experimental approaches will continue to evolve.

Animals↗
PubMed2005

beta-Adrenergic receptor polymorphisms and responses during titration of metoprolol controlled release/extended release in heart failure.

OBJECTIVE: beta-Blockers require careful initiation and titration when used in patients with heart failure. Some patients tolerate beta-blocker therapy initiation without difficulty, whereas in other patients this period presents clinical challenges. We tested the hypothesis that polymorphisms at codons 389 (Arg389Gly) and 49 (Ser49Gly) of the beta(1)-adrenergic receptor would be associated with differences in initial tolerability of beta-blocker therapy in patients with heart failure. We also tested whether polymorphisms in the beta(2)-adrenergic receptor, G-protein alpha s subunit (G(s)alpha), and cytochrome P450 (CYP) 2D6 genes or S-metoprolol plasma concentrations were associated with beta-blocker tolerability. METHODS: Sixty-one beta-blocker-naive patients with systolic heart failure were prospectively enrolled. Patients began taking 12.5 to 25 mg metoprolol controlled release/extended release with titration every 2 weeks (as tolerated) to 200 mg/d or the maximum tolerated dose over a period of 8 to 10 weeks. Decompensation was the composite of death, heart failure hospitalization, increase in other heart failure medications, or need to discontinue metoprolol. End points were assessed during the titration period. RESULTS: The overall rate of decompensation was not different between the codon 49 or 389 genotypes. However, a significantly greater percentage of patients with the Gly389 variant required increases in heart failure medications as compared with Arg389 homozygotes (48% versus 14%, respectively; P = .006). Similarly, patients with the Ser49 homozygous genotype were significantly more likely to require increases in concomitant heart failure therapy as compared with Gly49 carriers (41% versus 11%, respectively; P = .03). Neither CYP2D6 genotypes nor metoprolol pharmacokinetics differed between patients with and those without a decompensation event. There was no association between the beta(2)-adrenergic receptor or G(s)alpha polymorphisms with decompensated heart failure. CONCLUSIONS: Patients with the Gly389 variant and Ser49Ser genotype were significantly more likely to require increases in heart failure medications during beta-blocker titration and thus may require more frequent follow-up during titration.

Cytochrome P-450 CYP2D6↗
PubMed2005

Beta1-adrenergic receptor polymorphisms and left ventricular remodeling changes in response to beta-blocker therapy.

OBJECTIVE: Large variability exists in the improvement in left ventricular (LV) function from beta-blocker treatment. We hypothesized that polymorphisms at codon 389 (Arg389Gly) and 49 (Ser49Gly) in the beta1-adrenergic receptor (AR) gene were associated with LV reverse remodeling changes in response to beta-blocker therapy among heart failure patients. METHODS: We prospectively enrolled 61 beta-blocker naive patients with systolic heart failure. Patients underwent baseline echocardiography followed by metoprolol CR/XL. The dose was doubled on a biweekly basis up to 200 mg/day or attainment of maximum tolerated dose. Echocardiography was repeated after the patient received the target or highest tolerated dose for 3 months. RESULTS: Among patients with the Arg389Arg genotype, ejection fraction (EF) increased from 23+/-5 to 29+/-10 (P=0.008). Gly389 carriers did not demonstrate any significant change in EF (22+/-9 to 23+/-11; P=0.45). There was a significant between-group difference in EF by genotype (P=0.04). The Arg389Arg genotype was also associated with significantly greater reductions in LV end-diastolic and end-systolic diameters compared to Gly389 carriers. Patients with the Gly49 variant also had a significantly greater reduction in LV end-diastolic diameter compared to Ser49 homozygotes. Multiple regression analysis modeling revealed that the codon 389 polymorphism was a significant predictor of an improvement in EF and both codon 49 and 389 polymorphisms were significant predictors of final LV end-diastolic diameter. CONCLUSIONS: Heart failure patients with the Arg389Arg genotype and Gly49 carriers had greater improvements in LV remodeling from beta-blocker treatment.

Adrenergic beta-Antagonists↗
PubMed2005

Hypertension pharmacogenomics: current status and future directions.

Hypertension is the most common chronic disease in the Western world, and while there are many drug classes from which to choose therapy, only 34% of North Americans currently have their blood pressure controlled. The potential clinical utility of pharmacogenomics in helping to guide antihypertensive drug therapy selection is described. The hypertension pharmacogenetics literature is reviewed, which highlights that only a small fraction of the genes that likely contribute to antihypertensive response have been studied to date. The genes for alpha-adducin (diuretic response), the beta1-adrenergic receptor (beta-blocker response) and angiotensinogen (response to multiple drug classes) are among the genes with the most compelling data (based on replication) as pharmacogenetic candidates. Potential limitations of current studies are also discussed. These include reliance on clinic blood pressure, which is probably a suboptimal response phenotype, and the relatively small sample sizes of most studies to date. Also discussed is the relatively simplistic genetic approach that has been taken, which has focused largely on a single gene or single nucleotide polymorphism within a gene. Multiple ways to overcome these potential limitations are described. Hypertension pharmacogenomics holds tremendous potential for providing a mechanism by which management of hypertensive patients might be improved, and future studies should help move this field towards its clinical potential.

Humans↗
PubMed2004

Influence of gender and race on hemodynamic response to dobutamine during dobutamine stress echocardiography.

This study sought to determine the influence of gender and/or race on the hemodynamic response to dobutamine during dobutamine stress echocardiography. Blood pressure response patterns differed by gender and race, and completion of testing was often limited because of adverse events, namely, hypertension. Gender and racial differences in blood pressure response merit consideration as potential contributors to the suboptimal response in dobutamine stress testing.

Adult↗
PubMed2004

Pharmacokinetics and CYP2D6 genotypes do not predict metoprolol adverse events or efficacy in hypertension.

OBJECTIVE: Beta-Blocker use can be associated with adverse effects that may have an impact on adherence or harm patients. The commonly prescribed beta-blocker metoprolol is metabolized by the polymorphic cytochrome P450 (CYP) 2D6 enzyme, resulting in widely variable drug exposure. We investigated whether metoprolol plasma concentrations, CYP2D6 polymorphisms, or genotype-derived phenotype was associated with adverse effects or efficacy in patients with hypertension. METHODS: Fifty hypertensive patients received metoprolol by use of a dose-titration algorithm until target blood pressure was reached, intolerable side effects occurred, or maximal daily dose was achieved. CYP2D6 genotype was determined by methods based on polymerase chain reaction-restriction fragment length polymorphism and included 19 allelic variants. Patients were assigned to standard phenotype groups on the basis of genotype. Patients were also assigned activity scores based on functional activity of the alleles. General and dose-limiting adverse events and blood pressure responses were analyzed in relation to metoprolol steady-state pharmacokinetic profile and CYP2D6 genotype-derived phenotype. RESULTS: Poor metabolizers had a significantly longer elimination half-life, higher S-metoprolol area under the plasma concentration-time curve (AUC), and lower oral clearance (P < or = .007 for all parameters). There was a 29.6-fold variability in AUC among extensive metabolizers, which was largely explained by CYP2D6 activity scores (P = .032 for ordered differences in AUC by activity score among extensive metabolizers). Overall general and dose-limiting adverse event rates were 46% and 14%, respectively. General adverse event rates did not differ by AUC quartile (66.7% [95% confidence interval (CI), 35.4%-88.7%] and 41.7% [95% CI, 16.5%-71.4%] in the lowest and highest quartiles, respectively; P = .09 among all quartiles). Dose-limiting adverse event rates were also not different by AUC quartile (16.7% [95% CI, 2.9%-49.1%] and 8.3% [95% CI, 0.4%-40.2%] in the lowest and highest quartiles; P = .35 among all quartiles). Furthermore, adverse event rates did not differ by activity scores or between extensive, intermediate, or poor metabolizers. Antihypertensive response rate and blood pressure changes also were not influenced by differences in plasma concentrations or CYP2D6 genotypes. CONCLUSIONS: As expected, CYP2D6 genotype-phenotype correlates with differences in metoprolol pharmacokinetics. However, there was no association between variable pharmacokinetics or CYP2D6 genotype and beta-blocker-induced adverse effects or efficacy.

Adrenergic beta-Antagonists↗
PubMed2004

Differences in drug pharmacokinetics between East Asians and Caucasians and the role of genetic polymorphisms.

Interethnic variability in pharmacokinetics can cause unexpected outcomes such as therapeutic failure, adverse effects, and toxicity in subjects of different ethnic origin undergoing medical treatment. It is important to realize that both genetic and environmental factors can lead to these differences among ethnic groups. The International Conference on Harmonization (ICH) published a guidance to facilitate the registration of drugs among ICH regions (European Union, Japan, the United States) by recommending a framework for evaluating the impact of ethnic factors on a drug's effect, as well as its efficacy and safety at a particular dosage and dosage regimen. This review focuses on the pharmacokinetic differences between East Asians and Caucasians. Differences in metabolism between East Asians and Caucasians are common, especially in the activity of several phase I enzymes such as CYP2D6 and the CYP2C subfamily. Before drug therapy, identification of either the genotype and/or the phenotype for these enzymes may be of therapeutic value, particularly for drugs with a narrow therapeutic index. Furthermore, these differences are relevant for international drug approval when regulatory agencies must decide if they accept results from clinical trials performed in other parts of the world.

Asian People↗
PubMed2004

Sequencing complex diseases With HapMap.

Determining the patterns of DNA sequence variation in the human genome is a useful first step toward identifying the genetic basis of a common disease. A haplotype map (HapMap), aimed at describing these variation patterns across the entire genome, has been recently developed by the International HapMap Consortium. In this article, we present a novel statistical model for directly characterizing specific sequence variants that are responsible for disease risk based on the haplotype structure provided by HapMap. Our model is developed in the maximum-likelihood context, implemented with the EM algorithm. We perform simulation studies to investigate the statistical properties of this disease-sequencing model. A worked example from a human obesity study with 155 patients was used to validate this model. In this example, we found that patients carrying a haplotype constituted by allele Gly16 at codon 16 and allele Gln27 at codon 27 genotyped within the beta2AR candidate gene display significantly lower body mass index than patients carrying the other haplotypes. The implications and extensions of our model are discussed.

Body Mass Index↗