Antipsychotic-induced extrapyramidal syndromes. Risperidone compared with low- and high-potency conventional antipsychotic drugs.

Aim: To compare the risk of extrapyramidal syndromes (EPS) between patients using risperidone and those using low-potency conventional antipsychotic drugs (APDs) in outpatient clinical practice, as measured by the use of anticholinergic medication. We tried to replicate results from previous clinical trials that compared risperidone with high-potency APDs.

Method: Data was obtained from the PHARMO database containing filled prescriptions of 450,000 community-dwelling people in The Netherlands from 1986 to 1998.

Determinants of pharmacists' interventions linked to prescription processing.

Aim Of Study: The role of pharmacists in today's healthcare is changing rapidly. As they are close to the prescribing process, pharmacists are in the position to identify and adjust prescribing errors before dispensing. The objective of this study was to identify relevant determinants of interventions directly linked to prescription processing in community pharmacy.

Fluoroquinolone use and the change in incidence of tendon ruptures in the Netherlands.

Introduction: Shortly after their introduction, fluoroquinolones were associated with reports of tendinitis and tendon rupture. During the past years, the number of reports has risen, possibly because of an increased use of fluoroquinolones. In this study, we describe the use of fluoroquinolones in the Dutch community and the possible public health effects of an association between fluoroquinolone use and tendon ruptures.

An epidemiological approach to assess the economic burden of NSAID-induced gastrointestinal events in The Netherlands.

Objective: To use the population attributable risk (PAR) to estimate the treatment costs resulting from nonsteroidal anti-inflammatory drug (NSAID)-induced gastrointestinal (GI) morbidity.

Design: Two case-control studies with the following outcomes: (i) the start of therapy with gastroprotective agents (GPAs) and (ii) hospitalisations for GI events.

Setting: Community-dwelling inhabitants of defined areas in The Netherlands covering the period 1989 to 1998.

Tendon disorders attributed to fluoroquinolones: a study on 42 spontaneous reports in the period 1988 to 1998.

Objective: Fluoroquinolone antibiotics have been associated with tendinitis and tendon rupture. In this paper we report on the followup of 42 spontaneous reports of fluoroquinolone-associated tendon disorders.

Methods: This study is based on cases of fluoroquinolone-associated tendon disorders reported to the Netherlands Pharmacovigilance Foundation Lareb and the Drug Safety Unit of the Inspectorate for Health Care between January 1, 1988, and January 1, 1998.

Quick titration of pergolide in cotreatment with domperidone is safe and effective.

The purpose of the study was to analyze efficacy and safety of quick pergolide titration combined with domperidone. In an open-label prospective study, pergolide was titrated in 16 days to a maximum of 3 mg/d doses as adjunctive treatment to L-Dopa in 10 elderly patients with Parkinson's disease. Sixty milligrams domperidone was started 2 days before and and continued during the pergolide titration period to prevent side effects.

Evaluating adverse cardiovascular effects of drug treatment for benign prostatic hyperplasia (BPH): methodological considerations.

When studying the effects of drug exposure in diseases with a long asymptomatic clinical course, exposure classification may be biased by the gradually developing "visibility" of the disease. Benign prostatic hyperplasia (BPH) is such a disease. We found that cardiovascular morbidity is two times more prevalent in patients starting drug treatment for BPH when compared to age-matched population controls.

Use of sympathomimetic drugs leads to increased risk of hospitalization for arrhythmias in patients with congestive heart failure.

Background: Sympathomimetic agents have a direct positive chronotropic effect on heart rate and may cause hypokalemia, even when administered by inhalation. In selected patients (e.g.

Cyclical etidronate use is not associated with symptoms of peptic ulcer disease.

Objective: To investigate whether the alkylbisphosphonate etidronate is associated with an increased risk of gastrointestinal symptoms.

Methods: We conducted an observational follow-up study on a possible relationship between etidronate use and the risk of gastrointestinal symptoms in a cohort of 2754 women over 50 years of age. The study was performed with data on drug prescriptions obtained from the PHARMO database in the Netherlands.

Use of prevalence and incidence measures to describe age-related prescribing of antidepressants with and without anticholinergic effects.

To evaluate whether physicians avoid prescribing highly anticholinergic antidepressants (AAD) in the elderly, a population-based retrospectively data analysis was performed using databases from a Dutch health insurance company. Data collected on approximately 240,000 persons covered the period from 1 July 1993 to 1 January 1996. The prevalence and the incidence (number of new starters) of antidepressant use was measured over 1994 and 1995.

Influence of question structure on the recall of self-reported drug use.

Epidemiological studies often rely on self-reported information as a source of drug exposure. Several studies have evaluated the accuracy of self-reported information on drug use. The influence of question structure on the accuracy of recall, however, has not been studied extensively in these studies.

Agreement between self-reported antihypertensive drug use and pharmacy records in a population-based study in The Netherlands.

From 1987 to 1991, over 36,000 men and women aged 20-59 years have been examined in the Monitoring Project on Cardiovascular Disease Risk Factors in The Netherlands. Classification of the treatment status of hypertensives in this population-based study was based on self-administered questionnaires. In order to assess the accuracy of self-reported antihypertensive drug use we compared the questionnaire information with computerized pharmacy records from a sample of 372 hypertensive subjects.

Asthma exacerbations during first therapy with long acting beta 2-agonists.

Long-acting beta 2-agonists (LBA) have become an important therapeutic strategy in the treatment of asthma. There is, however, debate whether LBA increase the risk of asthma exacerbations (AE). We studied whether the risk of AE was increased in patients starting LBA therapy and whether the risk was associated with severity.

Venous thromboembolism among new users of different oral contraceptives.

New use of third generation oral contraceptives is associated with a four-fold increased risk of venous thromboembolism compared with users of second generation oral contraceptives, particularly among young, healthy women.

A population-based case-cohort study of drug-associated agranulocytosis.

Background: Agranulocytosis is a life-threatening disorder, often caused by drugs. Incidences or risks of drug-induced agranulocytosis are not well known, since it is rare.

Methods: To determine the risk of drug-associated agranulocytosis as a reason for admission to Dutch hospitals, we performed a population-based case-cohort study.

NSAIDs associated with increased risk of congestive heart failure in elderly patients taking diuretics.

Background: Both diuretics and nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used, in particular among the elderly. The use of NSAIDs may decrease the efficacy of diuretics and induce congestive heart failure (CHF) in patients treated with diuretics.

Objective: To investigate the risk of CHF associated with combined use of diuretics and NSAIDs in patients older than 55 years.

Application of the ATC/DDD methodology to monitor antibiotic drug use.

In order to monitor the use of antibiotics, it is essential to have comprehensive data on drug consumption. The findings of drug utilisation studies can serve to describe the pattern of drug use in a particular population, to detect areas of concern, and to evaluate the impact of interventions taken to influence the use of drugs. In the present study, the Anatomical Therapeutical Chemical Classification/Defined Daily Doses (ATC/DDD) system developed by the World Health Organisation was evaluated.

Dispensing epilepsy medication: a method of determining the frequency of symptomatic individuals with seizures.

We estimated the prevalence and incidence of epilepsy in The Netherlands using drug-dispensing information from the PHARMO database, containing medication histories of nearly 300,000 individuals. An algorithm based on antiepileptic drug prescription records was used to identify patients with epilepsy requiring medication for seizure control. The algorithm was validated by comparing positive algorithm identifications to medical diagnoses from general practitioners and hospital records.

Neuro-psychiatric effects of antimalarials.

Objective: To study the neuro-psychiatric adverse effects of antimalarial drugs.

Setting: Persons who visited a Travel Clinic in Rotterdam over a period of 3 months.

Design: Prospective cohort study on 394 persons taking mefloquine, 493 persons taking proguanil and 340 persons not taking antimalarial drugs who visited Africa, South America, Asia, or the Middle East.

Current use of thiazide diuretics and prevention of femur fractures.

A case control study of a defined population from The Netherlands was performed to evaluate the risk of femur fractures associated with the use of thiazide diuretics. Included were 386 patients hospitalized for femur fractures between 1986 and 1990 who were residents and 45 years of age and older. Per case, one age-, sex-, pharmacy-, and general practitioner-matched control was chosen from the general population.

Use of antiepileptic drugs in a community-dwelling Dutch population.

We compared the treatment policy for patients with epilepsy in six Dutch cities, comprising 302, 149 inhabitants, with the treatment policies of a secondary referral center (a university hospital) and tertiary referral centers (outpatient departments of epilepsy centers). By comparing the prevalence of individuals receiving antiepileptic drugs in the six cities with the epidemiologic data for epilepsy in Rochester, Minnesota, we concluded that prescription data offer a suitable means by which to estimate the prevalence of epilepsy in a community. To compare prescriptions in cases of polytherapy, we normalized data by using defined daily doses published by the WHO Collaborating Center for Drugs Statistics Methodology and the Nordic Council on Medicines and concluded that the defined daily doses of antiepileptic drugs should be further elaborated.

[Reasons to report or not report side effects of drugs to the national monitoring system in the Netherlands].

Objective: To assess the awareness of medical practitioners in the Netherlands regarding the national voluntary reporting scheme for adverse reactions to drugs, and the reasons for non-reporting.

Design: Questionnaire.

Setting: Netherlands Centre for Monitoring of Adverse Reactions to Drugs.

Asthma medications and disease exacerbations: an epidemiological study as a method for asthma surveillance.

Recent experimental and epidemiological studies have suggested that outcomes of asthma are significantly influenced by treatment patterns. This study was conducted in order to investigate the links between treatment patterns in asthmatics and occurrence of disease exacerbations. We performed a nested case-control study in a cohort of 680 asthmatics identified between 1986 and 1991 in a drug dispensing database.

Benzodiazepines and the risk of falling leading to femur fractures. Dosage more important than elimination half-life.

Background: In the past decade, the use of benzodiazepines has been identified as a major independent risk factor for accidental falls.

Objective: To study the role of dosing, timing, elimination half-life, and type of benzodiazepine in relation to the occurrence of accidental falls leading to hospitalization for femur fractures.

Methods: A 1:3 age-, sex-, and pharmacy-matched case-control study was performed using data from a Dutch record linkage system (PHARMO) (N = 300,000).