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Anthonius de Boer

Publications and source records attributed to Anthonius de Boer.

44 records · Page 3Linked to original sources
PubMed2002

Antipsychotic-induced extrapyramidal syndromes and cytochrome P450 2D6 genotype: a case-control study.

To study the association between polymorphism of the cytochrome P450 2D6 gene (CYP2D6) and the risk of antipsychotic-induced extrapyramidal syndromes, as measured by the use of antiparkinsonian medication. Data for this case-control study were obtained from a psychiatric hospital where newly admitted patients are routinely screened for several CYP2D6 mutant alleles. Cases were patients prescribed antiparkinsonian medication during oral antipsychotic drug treatment in the period September 1994 to August 2000. They were divided into those using an antipsychotic drug the metabolic elimination of which depends on the activity of the CYP2D6 enzyme ('CYP2D6-dependent') and those using other antipsychotic drugs. We formed a control group of antipsychotic drug users for both case groups using a matching ratio of 3 : 1 (controls : cases). Control patients were matched on whether or not their prescribed antipsychotic drug was CYP2D6-dependent. Odds ratios for patients who were slow metabolizers versus patients who were extensive metabolizers were calculated using conditional logistic regression and were adjusted for age, gender, dose and other potential confounding factors. We identified 77 case patients who were prescribed a CYP2D6-dependent antipsychotic drug and 54 case patients who were prescribed non CYP2D6-dependent antipsychotic drugs. Among the case- and control-patients using a CYP2D6-dependent antipsychotic drug, the poor metabolizers were more than four times more likely to start with antiparkinsonian medication than the extensive metabolizers (odds ratio 4.44; 95% confidence interval 1.11-17.68). An increased risk was not observed for patients using non CYP2D6-dependent antipsychotic drugs (odds ratio 1.20; 95% confidence interval 0.21-6.79). Genetically impaired CYP2D6 activity can increase the risk of antipsychotic-induced extrapyrimidal syndromes. Poor metabolizers should have their antipsychotic drug dosage reduced when the metabolism of the prescribed drug depends on CYP2D6 activity or should receive an antipsychotic drug that is not CYP2D6-dependent.

Adult↗
PubMed2002

The effectiveness of hydroxy-methylglutaryl coenzyme A reductase inhibitors (statins) in the elderly is not influenced by apolipoprotein E genotype.

We aimed to assess whether the effectiveness of statins in the prevention of myocardial infarction, stroke and total mortality is influenced by apolipoprotein E (apoE) genotype in an elderly population. We used data from the Rotterdam Study, a prospective population-based cohort study in the Netherlands which started in 1990 and included 7983 subjects aged 55 years and older. Subjects who were treated with cholesterol lowering drugs at baseline or with a serum total cholesterol > or = 6.5 mmol/l at baseline were included. We compared the incidence of myocardial infarction, stroke and total mortality in subjects who received > or = 2 years of statin treatment with that in subjects who had been treated for less than 2 years, and in untreated subjects, using a Cox proportional hazard model with cumulative statin use defined as time-dependent covariates. The adjusted relative risk of all-cause mortality was 0.79 [95% confidence interval (CI) 0.51-1.22] and of myocardial infarction and stroke 0.50 (95% CI 0.28-0.91) for subjects treated with statins for > or = 2 years compared to untreated subjects. The adjusted relative risks for subjects with the epsilon4 allele were 0.91 (95% CI 0.45-1.84) for all-cause mortality and 0.63 (95% CI 0.23-1.78) for myocardial infarction and stroke. In subjects without the epsilon4 allele, adjusted relative risks were 0.71 (95% CI 0.41-1.24) for all-cause mortality and 0.46 (95% CI 0.22-0.95) for myocardial infarction and stroke. We found a protective effect of statins on the risk of myocardial infarction and stroke that was independent of apoE genotype. The protective effect of statins on total mortality was not statistically significant, but did not seem to differ between subjects with different apoE genotypes.

Aged↗
PubMed2002

Discrepancies between medical and pharmacy records for patients on anti-HIV drugs.

OBJECTIVE: To compare and evaluate drug notations in outpatient medical records and in pharmacy records in a cohort of HIV-1-infected patients treated with antiretroviral drugs. METHODS: Data on 103 patients were obtained from January 1, 1998, through December 31, 1999, by medical chart review and collection of pharmacy records. Two analyses were performed. First, antiretroviral drugs and comedication in the pharmacy records were documented and compared with their appearance in the outpatient medical records. Second, a detailed comparison was performed at 5 time points during the study period for the antiretroviral drugs. Generic name, formulation, strength, and frequency of dosing as registered in the outpatient medical records were compared with those registered in the pharmacy records. RESULTS: Total drug dispensation was 1607 (366 and 1241 antiretroviral drugs and comedication, respectively). The first screening resulted in a total discrepancy of 55.1% (n = 885), of which 97.1% (n = 859) was attributed to the comedication and 2.9% (n = 26) to the antiretroviral drugs. The discrepancy for the antiretroviral drugs at the specific time points ranged from 5.1% to 12.6% when the generic name only was used, and from 7.1% to 17% when formulation, strength, and frequency of dosing were also taken into account. CONCLUSIONS: The observed discrepancy between outpatient medical records and pharmacy records mainly concerns the comedication. For the antiretroviral drugs fewer, but still substantial, discrepancies were observed. These results indicate that full exchange of information conceming drug use in this population between general practitioners and specialists (infectious disease) is lacking.

Adult↗
PubMed2002

Lipid-lowering drug use and cardiovascular events after myocardial infarction.

BACKGROUND: The benefits of lipid-lowering drug treatment for the secondary prevention of coronary heart disease have been well established by randomized, controlled trials. Nonetheless, the risk of events has not been compared directly for inhibitors of hydroxymethylglutaryl coenzyme A reductase (statins) and non-statin lipid-lowering drugs. Further, it remains uncertain whether patients in usual practice who are treated with lipid-lowering drugs after myocardial infarction (MI) gain a similar benefit with regard to the risk of cardiovascular events compared with patients in randomized, controlled trials. OBJECTIVE: To assess the association between lipid-lowering drug therapies in usual clinical practice and the risk of cardiovascular events in patients with a first MI who were discharged alive from the hospital. METHODS: An inception-cohort study was performed among 1956 enrollees of Group Health Cooperative who sustained an incident MI between July 1986 and December 1996 and survived for at least 6 months after hospitalization. Subjects with untreated low-density-lipoprotein cholesterol concentrations > 130 mg/dL or untreated total cholesterol concentrations >200 mg/dL were included. The median duration of follow-up after the first MI was 3.3 years. Medical record review was used to collect information on cardiovascular risk factors. Computerized pharmacy records were used to assess antihyperlipidemic drug use during the first 6 months after hospitalization. RESULTS: Compared with 1263 subjects who did not receive lipid-lowering drug treatment, 373 subjects who received statins had a lower risk of recurrent coronary events (relative risk [RR] 0.59; 95% CI 0.39 to 0.89), stroke (RR 0.82; 95% CI 0.35 to 1.95), atherosclerotic cardiovascular mortality (RR 0.49; 95% CI 0.21 to 1.13), and any atherosclerotic cardiovascular event (RR 0.63; 95% CI 0.40 to 0.98). Among 320 subjects who used non-statin drug therapies, the RRs were 0.66 (95% CI 0.45 to 0.97) for recurrent coronary events, 0.95 (95% CI 0.46 to 1.95) for stroke, 0.68 (95% CI 0.35 to 1.32) for cardiovascular mortality, and 0.77 (95% CI 0.53 to 1.11) for any atherosclerotic cardiovascular event, compared with untreated hyperlipidemic patients. CONCLUSIONS: In this study of MI survivors, the use of lipid-lowering drug therapies after hospitalization was associated with a reduced risk of cardiovascular events. These results emphasize the importance of lipid-lowering drug treatment in patients with hyperlipidemia who survive a first MI.

Cholesterol↗
PubMed2002

Myopathy due to statin/fibrate use in the Netherlands.

OBJECTIVE: To estimate the number of expected cases of myopathy based on the prevalence of lipid-lowering drug use, and to compare this number with the observed number of cases of myopathy due to lipid-lowering drug use in the Netherlands. METHODS: Prevalence of lipid-lowering drug use in 1998 was estimated by using data from the PHARMO record linkage system comprising pharmacy records linked to hospital admission data. The expected number of cases of myopathy was calculated by multiplying the total number of person-years of lipid-lowering drug use by the excess incidence rates of myopathy due to those drugs as reported in the literature. The observed number of cases was obtained from PHARMO and the Dutch Pharmacovigilance Foundation Lareb. RESULTS: Based on the estimated prevalence of lipid-lowering drug use in the Netherlands in 1998 (n = 520 800), we expected 60 cases of idiopathic myopathy due to hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) or fibric acid derivatives (fibrates). This low number was confirmed by data from PHARMO (n = 11; none of these were related to current use of lipid-lowering drugs) and Lareb (n = 43). CONCLUSIONS: The expected number of statin- or fibrate-related idiopathic myopathy is low and observed numbers are even lower in the Netherlands. This should, therefore, not compromise continued use of lipid-lowering drugs.

Anticholesteremic Agents↗
PubMed1999

Excess stroke among hypertensive men and women attributable to undertreatment of hypertension.

BACKGROUND AND PURPOSE: Most population-based studies indicate that a considerable proportion of hypertensive subjects are undertreated and that undertreatment is more prevalent among hypertensive men than among hypertensive women. The aim of our study was to investigate the consequences of undertreatment of hypertension for women and men in terms of stroke occurrence. METHODS: Approximately 45 000 men and women aged >/=20 years were examined in 2 population-based studies in the Netherlands. A cohort of 2616 hypertensive subjects (pharmacologically treated hypertensives and untreated hypertensives who needed pharmacological treatment according to the severity of their hypertension and the coexistence of additional cardiovascular risk factors) was selected for a follow-up study. Follow-up (mean duration, 4.6 years) was complete for 2369 (91%) of the enrolled hypertensive subjects. RESULTS: Compared with treated and controlled hypertensives, the relative risks of stroke for treated and uncontrolled hypertensives and for untreated hypertensives who needed treatment were 1.30 (95% CI, 0.70 to 2.44) and 1.76 (95% CI, 1.05 to 2.94), respectively. These relative risks and the prevalence of (undertreated) hypertension in the total population of 45 000 subjects were used to estimate the number of strokes in the Netherlands attributable to undertreatment. Among hypertensive men and women aged >/=20 years in the Netherlands, the proportions of strokes attributable to treated but uncontrolled blood pressure were 3.1% (95% CI, -5.2% to 18.7%) and 4.1% (95% CI, -7.2% to 20.7%), respectively. For untreated hypertensive men and women who should have been treated, these proportions were 22.8% (95% CI, 0.8% to 38.4%) and 25.4% (95% CI, 0. 5% to 42.5%), respectively. CONCLUSIONS: Increasing the detection of hypertension and improving adherence to current guidelines might prevent a considerable proportion of the incident strokes among hypertensives. The potential impact of achieving control of blood pressure in patients already being treated on the reduction of strokes requires further investigation.

Adult↗
PubMed1998

Is placebo analgesia mediated by endogenous opioids? A systematic review.

This systematic review assesses six experimental studies into the mechanism of placebo analgesia in human subjects suffering from clinical pain or experimentally induced ischaemic arm pain. Due to their sophisticated designs, these studies probably provide the best evidence that placebo analgesia exists. They also indicate that placebo analgesia is mediated by endogenous opiates. However, there seems to be room for additional studies.

Analgesia↗