Genetic and environmental factors affecting the coumarin anticoagulant level

This introductory chapter has illustrated that various factors, such as genetic factors, drugs, diet and intercurrent diseases may affect anticoagulation levels. Most of the clinical and pharmacological data related to coumarin anticoagulants have so far been obtained from studying warfarin. Because of the different pharmacokinetic properties of each individual drug, the results of these studies can probably not be directly extrapolated to the other coumarin anticoagulants. Therefore, the aim of this thesis was to study the various genetic and environmental factors affecting the anticoagulation levels of acenocoumarol or phenprocoumon among outpatients of an anticoagulation clinic. In chapter 2 genetic factors influencing the coumarin anticoagulant level are examined. Chapter 2.1 describes how the coumarin anticoagulant dose is affected by polymorphisms of the cytochrome P450 enzyme 2C9 allele. In chapter 2.2 we describe the influence of these polymorphisms on the occurrence of bleeding complications. CYP2C9 variant alleles seem to have several biological consequences. For instance, it has been associated with an increased risk of myocardial infarction in women [57]. Therefore, in chapter 2.3 the risk of myocardial infarction was studied in patients with a CYP2C9 variant allele compared to patients with the wild type genotype. Chapter 2.4 concerns the influence of apolipoprotein E genotype on the coumarin anticoagulant level. In chapter 3, several drugs are identified with a high risk of overanticoagulation during coumarin use. Chapters 3.1 and 3.2 focus on antibacterial drugs and antifungal agents, chapters 3.3 on laxatives, and 3.4 on nonsteroidal anti-inflammatory drugs as risk factors for overanticoagulation. The study described in chapter 4 aims at investigating the influence of heart failure on the anticoagulant level. The role of dietary intake of vitamin K as a risk factor for overanticoagulation is evaluated in chapter 5. Finally, in chapter 6 the strengths and limitations of this thesis are discussed, together with the implications for coumarin anticoagulant therapy, and suggestions for future research are given

Cough due to ace inhibitors: A case control study using automated general practice data

Objectives: To determine the risk of coughing as an adverse reaction to ACE inhibitors under everyday circumstances in a large population, and to study whether this adverse effect was duration or dose dependent. Design: A population-based case-control study. Setting: Ten general practices of 14 Dutch general practitioners (GP), in which all consultations, morbidity and medical interventions, including drugs prescribed, were registered over the 18 month period from 1st September, 1992 to 1st March, 1994. Subjects: 1458 patients with incident coughing and up to four controls per case were obtained (total 4182 controls), matched for GP. All cases and controls were 20 years or older and had no record of respiratory infection, influenza, tuberculosis, asthma, chronic bronchitis, emphysema, congestive heart failure, sinusitis, laryngitis, haemoptysis or respiratory neoplasms during the study period. Results: Cases were 2.1-times more likely than controls to have been exposed to ACE inhibitors (95% CI 1.5-3.1), but after adjustment the odds ratio was 1.4 (95% CI 0.9-2.1). The crude odds ratio for captopril was 1.3 (95% CI 0.7-2.5), for enalapril 2.6 (95% CI 1.6-4.2) and for lisinopril 2.0 (95% CI 0.5-9.3). The adjusted odds ratio for captopril was 0.9 (95% CI 0.4-1.7), for enalapril 1.7 (95% CI 1.03-2.8) and for lisinopril 1.7 (95% CI 0.4-7.9). For patients who had been on ACE inhibitor treatment for no longer than 2 months the odds ratio was 4.8 (95% CI 1.7-13.3). The odds ratio declined to 2.0 (95% CI 1.1-3.8) for those who had taken an ACE inhibitor for 2-6 months, and to 1.6 (95% CI 0.9-2.7) for those on ACE-inhibitors for more than 6 months. Conclusion: The risk of coughing was increased twofold among ACE inhibitor users, but the odds ratios were no longer significant after controlling for several confounding factors. The risk of developing cough due to ACE-inhibitors declines with the duration of treatment, possibly due to depletion of susceptible persons

The risk of overanticoagulation in patients with heart failure on coumarin anticoagulants

Heart failure has been identified as a risk factor for increased coumarin anticoagulant responsiveness in several small-scale experiments. Epidemiological studies quantifying the risk of overanticoagulation by heart failure in a non-selected population on coumarins are scarce. Therefore, we investigated whether patients with heart failure have an increased risk of overanticoagulation and determined the effect of incidental heart failure on coumarin dose requirements. A cohort study of all patients was performed from an outpatient anticoagulation clinic treated with acenocoumarol or phenprocoumon between 1 January 1990 and 1 January 2000. All cohort members were followed until the first occurrence of an international normalized ratio (INR) ≥6.0, the last INR assessment, death, loss to follow-up, or end of the study period. Of the 1077 patients in the cohort, 396 developed an INR ≥6.0. The risk of overanticoag

Maternal Sociodemographic Factors Are Associated With Methylphenidate Initiation in Children in the Netherlands: A Population-Based Study

Multiple factors may contribute to the decision to initiate methylphenidate treatment in children such as maternal sociodemographic factors of which relatively little is known. The objective was to investigate the association between these factors and methylphenidate initiation. The study population included 4243 children from the Generation R Study in the Netherlands. Maternal sociodemographic characteristics were tested as determinants of methylphenidate initiation through a timedependent Cox regression analysis. Subsequently, we stratifed by mother-reported ADHD symptoms (present in 4.2% of the study population). When ADHD symptoms were absent, we found that girls (adjusted HR 0.25, 95%CI 0.16–0.39) and children born to a mother with a non-western ethnicity (compared to Dutch-Caucasian) (adjusted HR 0.42, 95%CI 015–0.68) were less likely to receive methylphenidate. They were more likely to receive methylphenidate when their mother completed a low (adjusted HR 2.29, 95%CI 1.10–4.77) or secondary (adjusted HR 1.71, 95%CI 1.16–2.54) education. In conclusion, boys and children born to a mother of Dutch-Caucasian ethnicity were more likely to receive methylphenidate, irrespective of the presence of ADHD symptoms

Fibrinolysis during liver transplantation is enhanced by using solvent/detergent virus-inactivated plasma (ESDEP)

After the introduction of solvent/detergent-treated plasma (ESDEP) in our hospital, an increased incidence of hyperfibrinolysis was observed (75% vs 29%; P = 0.005) compared with the use of fresh frozen plasma for liver transplantation. To clarify this increased incidence, intraoperative plasma samples of patients treated with fresh frozen plasma or ESDEP were analyzed in a retrospective observational study. During the anhepatic phase, plasma levels of D-dimer (6.58 vs 1.53 microg/mL; P = 0.02) and fibrinogen degradation products (60 vs 23 mg/L; P = 0.018) were significantly higher in patients treated with ESDEP. After reperfusion, differences increased to 23.5 vs 4.7 microg/mL (D-dimer, P = 0.002) and 161 vs 57 mg/L (fibrinogen degradation products, P = 0.001). The amount of plasma received per packed red blood cell concentrate, clotting tests, and levels of individual clotting factors did not show significant differences between the groups. alpha(2)-Antiplasmin levels, however, were significantly lower in patients receiving ESDEP during the anhepatic phase (0.37 vs 0.65 IU/mL; P < 0.001) and after reperfusion (0.27 vs 0.58 IU/mL; P = 0.001). Analysis of alpha(2)-antiplasmin levels in ESDEP alone showed a reduction to 0.28 IU/mL (normal >0.95 IU/mL) because of the solvent/detergent process. Therapeutic consequences for the use of ESDEP in orthotopic liver transplantation are discussed in view of an increased incidence of hyperfibrinolysis caused by reduced levels of alpha(2)-antiplasmin in the solvent/detergent-treated plasma. IMPLICATIONS: The use of solvent/detergent virus-inactivated plasma is of increasing importance in the prevention of human immunodeficiency virus and hepatitis C virus transmission. Since the use of this plasma during orthotopic liver transplantation has increased, the incidence of hyperfibrinolysis was observed. Clotting analysis of the patients revealed small alpha(2)-antiplasmin concentrations because of the solvent/detergent process

CYP1A2 and coffee intake and the modifying effect of sex, age, and smoking

Background: The enzyme CYP1A2 (cytochrome 1A2) is involved in the metabolism of certain drugs and caffeine, and its activity can be influenced by factors such as sex, age, and smoking. The single nucleotide polymorphism (SNP) rs762551A>C, which has also been studied for its modifying effect on cardiovascular disease, has been reported to alter enzyme activity. Objective: The objective was to study the effect of CYP1A2, sex, age, and smoking on coffee intake. Design: Within the Rotterdam Study, a population-based cohort, all coffee drinkers for whom genome-wide association data were available were selected. Because SNP rs762551 was not on the Illumina 550 platform, SNP rs2472299 was used as a proxy, with the A allele of rs762551 linked to the G allele of rs2472299. Linear regression analyses were used to determine the effect and interaction of rs2472299, sex, age, and smoking on coffee intake. Adjusted geometric means of coffee intake were calculated per genotype for the different smoking and sex strata by using multivariable general linear models. A combined analysis, with the use of a "risk score,"was performed to determine the contribution of each separate factor. Results: rs2472299G>A, female sex, and nonsmoking were significantly inversely related to coffee intake. Coffee intake was lowest in nonsmoking women homozygous for rs2472299G>A (3.49 cups/d; ∼436 mL). All factors contributed almost linearly to the intake of coffee, with the highest coffee intake in smoking men without the A allele (5.32 cups/d; ∼665 mL). Conclusion: rs2472299G>A, linked to rs762551A>C, sex, age, and smoking significantly contribute to coffee intake

Efficacy and Safety of High Potent P2Y12 Inhibitors Prasugrel and Ticagrelor in Patients With Coronary Heart Disease Treated With Dual Antiplatelet Therapy: A Sex-Specific Systematic Review and Meta-Analysis

Background Sex differences in efficacy and safety of dual antiplatelet therapy remain uncertain because of the underrepresentation of women in cardiovascular trials. The aim of this study was to perform a sex-specific analysis of the pooled efficacy and safety data of clinical trials comparing a high potent P2Y12 inhibitor+aspirin with clopidogrel+aspirin in patients with acute coronary syndrome. Methods and Results A systematic literature search was performed. Randomized clinical trials that compared patients following percutaneous coronary intervention/acute coronary syndrome who were taking high potent P2Y12 inhibitors+aspirin versus clopidogrel+aspirin were selected. Random effects estimates were calculated and relative risks with 95% CIs on efficacy and safety end points were determined per sex. We included 6 randomized clinical trials comparing prasugrel/ticagrelor versus clopidogrel in 43 990 patients (13 030 women), with a median follow-up time of 1.06 years. Women and men had similar relative risk (RR) reduction for major cardiovascular events (women: RR, 0.89 [95% CI, 0.80-1.00; men: RR, 0.84 [95% CI, 0.79-0.91) (P for interaction=0.39). Regarding safety, women and men had similar risk of major bleeding by high-potency dual antip

Prescription and indication trends of antidepressant drugs in the Netherlands between 1996 and 2012: A dynamic population-based study

Purpose: Antidepressant drug use increases worldwide. It is pivotal to closely monitor the use of antidepressants and to determine in what subpopulations the rise is most substantial. In a Dutch primary care database, we aimed to investigate the (sex- and age-specific) prevalence and incidence of antidepressant prescription and to monitor the indication of incident prescriptions over a 17-year period (1996-2012). Methods: This study, embedded in the Integrated Primary Care Information database, included all patients aged 10 years or older. Per calendar year, prevalence and incidence of antidepressant drug prescription were calculated by drug class (tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), and others), sex, and age. The indication of incident prescriptions (e.g., depression, anxiety, sleep disorders, and neuropathic pain) was determined based on the International Classification of Primary Care codes. Results: In total, 1.49 million patients were included. For all antidepressants together, the prevalence increased over time. However, incident prescription of specific SSRIs decreased from 2000 onward. During the study period, incidence and prevalence were higher in older and female patients. The increase in prevalence and the decrease in incidence were more pronounced in females than that in males. Furthermore, antidepressants were increasingly prescribed for indications such as neuropathic pain and sleep disorders. Conclusions: In Dutch primary care, prevalent prescription of antidepressants continued to increase, but incident prescription of particular SSRIs decreased from 2000 onward. In later years, antidepressants were less frequently prescribed for depression-related indications in incident users

Utilization patterns of antidepressants between 1991 and 2011 in a population-based cohort of middle-aged and elderly

Background: In middle-aged and older patients in whom antidepressant use increased in last decades, patterns of use might be of concern The objective of this study was to investigate the patterns of prevalence, incidence and duration of antidepressant use in an ageing population. Methods: All participants (aged. >. 45 years) from the population-based Rotterdam Study were followed from January 1st 1991 until death, loss to follow-up, or end of the study period (December 31st 2011). Antidepressant drug dispensing, based on pharmacy records, were subdivided into Tricyclic Antidepressants (TCAs), Selective Serotonin Reuptake Inhibitors (SSRIs) and other antidepressants. One-year prevalence, 5-year incidence and duration of antidepressant use were calculated. Results: Yearly prevalence of antidepressant use increased from 3.9% in 1991 to 8.3% of the population in 2011. The increase in SSRI use was 5.8-fold, whereas use of other antidepressants doubled and TCA use remained stable over time. Incidence of all antidepressantsdecreased from 23.9 to 14.2 per 1000 person-years between 1992 and 2011. The duration of a first treatment episode increased over time. Conclusion: Despite the prevalence of antidepressant use increased over time, incidence did not, which is most likely explained by a longer treatment duration and recurrent episodes