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Biomedical subjects

P A de Smet

Publications and source records attributed to P A de Smet.

At least 19 recordsLinked to original sources
PubMed2001

Nature, frequency and determinants of prescription modifications in Dutch community pharmacies.

AIMS: To examine the nature, frequency and determinants of prescription modifications in Dutch community pharmacies. METHODS: A prospective case-control study comparing modified prescriptions with nonmodified prescriptions was carried out in 141 Dutch community pharmacies. 2014 modified prescriptions (cases), collected in the selected pharmacies on a predetermined day in a specific period (25th February until 12th March 1999) and 2581 nonmodified prescriptions (controls) randomly selected on the same day were studied. The nature and frequency of prescription modifications and patient, drug and prescriber related determinants for a modified prescription were assessed. RESULTS: The overall incidence of prescription modifications was 4.3%, with a mean of 14.3 modifications per pharmacy per day. For prescription only medicines (POM) the incidence was 4.9%. The majority of POM modifications concerned a clarification (71.8%). In 22.2% a prescription could potentially have had clinical consequences when not altered; in more than half of the latter it concerned a dose error (13.7% of all cases). POM prescriptions of patients of 40-65 years had a significantly lower chance of modification compared with those of younger people (OR = 0.74 [0.64-0.86]). With respect to medication-class, we found a higher chance of POM modifications in the respiratory domain (OR = 1.48 [1.23-1.79]) and a decreased chance for nervous system POMs (OR = 0.71 [0.61-0.83]). With regard to prescriber-related determinants modifications were found three times more often in non printed prescriptions than in printed ones (OR = 3.30 [2.90-3.75]). Compared with prescriptions by the patient's own GP, prescriptions of specialists (OR = 1.82 [1.57-2.11]), other GP's (OR = 1.49 [1.02-2.17]) and other prescribers such as dentists and midwives (OR = 1.95 [1.06-3.57]) gave a higher probability of prescription modifications. When a GP had no on-line access to the computer of the pharmacy the chance of a modification was also higher (OR = 1.61 [1.33-1.94]). Multivariate analysis revealed that a nonprinted prescription was the strongest independent determinant of prescription modifications (OR = 3.32 [2.87-3.84]), remaining so after adjustment for GP computer link to the pharmacy and for type of prescriber. CONCLUSIONS: At least 30% of Dutch community pharmacies corrected 2.8 POM prescriptions per pharmacy per working day, which could potentially have had clinical consequences if not altered. If the study sample is representative for The Netherlands, Dutch community pharmacies correct a total of approximately 4400 of these prescriptions per working day. Using computerized systems to generate prescriptions is an important strategy to reduce the incidence of prescription errors.

Adult↗
PubMed2000

[Timing of administration of sulfonyl urea derivatives].

In daily practice the optimal time of administration of sulphonylurea derivatives is not always clear. Administration 30 minutes prior to meals allegedly offers the advantage that an active plasma level has been reached when food enters the gastrointestinal tract. Alleged disadvantages are higher risk of hypoglycaemia and poor compliance. In publications from Medline 1966-1999 the 24-hour availability of sulphonylurea derivates was the same after administration at different times. The absorption rate of glibenclamide and tolbutamide was not affected by food. Study results concerning gliclazide were contradictory. The absorption rate of glipizide was reduced after ingestion during breakfast. In several, partly the same, small studies the findings concerning the variation of the glucose level in time in patients with type 2 diabetes mellitus were equivocal. The pharmacokinetic and pharmacodynamic evidence that sulphonylurea derivatives should be taken 30 minutes before meals appears to be so limited that in our opinion it is out-weighed by the potential risk that this advice may compromise the drug compliance of users.

Biological Availability↗
PubMed1999

Patient education to users of oral hypoglycemic agents: the perspective of Dutch community pharmacists.

The purpose of this study was to indicate which patient education activities directed at users of oral hypoglycemic agents are desirable in Dutch community pharmacies and to explore which preconditions should be considered when implementing the desired activities. A qualitative study was conducted with a panel composed of seven pharmacists and seven technicians with considerable experience in giving advice to people with diabetes mellitus type 2. A consensus method was used, which consisted of a written questionnaire and a feedback discussion, to determine which activities were considered desirable and to identify which other health care providers should be involved. The way these activities should be implemented was explored by a focus-group discussion. The following goals of patient education activities were studied: 1) adherence to the dosage regimen, 2) adherence to lifestyle advices, 3) gaining awareness of effects and 4) self-monitoring. According to the members of the panel, patient education activities should be directed primarily at stimulating adherence to the dosage regimen, increasing awareness of side effects and improving the correct technical use of blood glucose meters. Activities directed at lifestyle advice seemed to be less desirable to the pharmacy staff. Preconditions that should be considered when implementing these activities were structural cooperation with GPs and diabetic nurses and specialization of tasks of pharmacy technicians. Our results indicate that deepening of existing tasks, such as stimulating adherence to the dosage regimen is desirable in developing patient education activities at users of oral hypoglycemic agents.

Administration, Oral↗
PubMed1998

['Weight reduction preparations' from Thailand: unexpected complication for the traveller].

Two series of Thai 'slimming agents' purchased apparently without a medical consultation or prescription (one directly in Thailand and the other one indirectly in the Netherlands) were submitted for chemical analysis. Fenfluramine and diazepam were present in both series. One series also yielded phenolphtalein and vitamin B substances, while sennosides were found in the other series. Apparently travellers may unwittingly take along potent medicines when they return from far countries.

Anti-Obesity Agents↗
PubMed1998

[Evaluation of drugs: efficacy, applicability, effectiveness and efficiency].

In view of rising costs of drugs and the limited budget, government, institutes, researchers, prescribers, pharmacists and pharmaceutical industries should have a standardized assessment system at their disposal on which to base their pharmacotherapeutic policy. Evaluation can be achieved in four successive steps, taking into account both therapeutical and financial aspects. The first two steps, determining efficacy and applicability, represent the current system of evaluating drugs before allowance to the market. Steps 3 and 4 describe the ways in which effectiveness and efficiency can be involved in the evaluation by means of (cost) effectiveness analysis. Achieving optimal results from this stepwise approach requires speedy acceptance of the currently available guidelines for effective and efficient research.

Cost-Benefit Analysis↗
PubMed1998

Reporting format for economic evaluation. Part I: Application to the Dutch healthcare system.

This article presents the first version of the reporting format for economic valuation that was created in 1995 by a multidisciplinary taskforce. The members of this taskforce come from a broad spectrum of backgrounds within the healthcare field and participated in the exercise voluntarily. The format presented should be understood as the preferred Dutch structure for the reporting of any study on economic evaluation. In view of the many areas of contention that exist within the field, this format only gives normative directions in those areas in which consensus exists, as evidenced by the current published international guidelines. A regular review and adaptation of this format will be needed to reflect advances in the field.

Delivery of Health Care↗
PubMed1998

Reporting format for economic evaluation. Part II: Focus on modelling studies.

This article presents the first version of a reporting format for modelling studies which is based on a general reporting format by our taskforce, which was published in the previous issue of this journal. The use of decision-analytical models for economic evaluations is increasing because, in practice, it is not always possible to derive information from prospective studies. However, the acceptance of modelling studies is generally lower than prospective studies not only because of the use of secondary data, but also because the reports of modelling studies do not always have sufficient transparency. Hence, a standardised reporting format may improve the transparency and, consequently, the acceptance of modelling studies. This article presents an example of a reporting format for economic evaluation based on modelling studies, which may facilitate the development of future guidelines for modelling studies. The format consists of a number of headings, which are followed by a brief recommendation on the content. This format does not deal with methodology and data management, but especially addresses validation and quality assurance, which may increase the transparency of the report.

Decision Support Techniques↗
PubMed1997

[Dexamethasone in a non-registered ointment from the Far East].

The Oriental cream Piyan Ping 999 has been used in the Netherlands as an unlicensed product. Chemical analysis revealed the presence of dexamethasone and dexamethasone-21-acetate in pharmacologically relevant concentrations. It was prescribed for 2 children; the 3-year-old girl had meanwhile developed bruises and small, poorly healing wounds.

Child↗
PubMed1994

Pharmacokinetic-pharmacodynamic drug interactions with nonsteroidal anti-inflammatory drugs.

The nonsteroidal anti-inflammatory drugs (NSAIDs) are very commonly prescribed, especially in the elderly population. In many countries more than 10 different NSAIDs are available. As the older pyrazole compounds like phenylbutazone, oxyphenbutazone and azapropazone are most prone to pharmacokinetic interactions, the use of these compounds should be avoided where possible. Acidic NSAIDs interact with bile acid-binding resins, resulting in decreased concentrations of NSAIDs in the blood. In earlier reports it was suggested that the absorption of NSAIDs was affected by antacids and sucralfate. More recently, it was shown that there is delayed absorption of these drugs, but there is no difference in the extent of absorption. Only salicylates had their urinary secretion enhanced by antacids, which increase the urinary pH to values > 7. Histamine H2-receptor antagonists can be combined safely with NSAIDs. The concomitant administration of probenecid increased the blood concentration of NSAIDs, so an enhanced anti-inflammatory effect can be expected when these 2 drugs are combined. More importantly, NSAIDs can cause pharmacokinetic drug-drug interactions with other drugs. As can be expected, interactions with drugs that have a small therapeutic window are most likely to be of clinical significance. For example, lithium, medium to high dose methotrexate and, to a lesser extent, cyclosporin may be affected by concomitant administration of an NSAID. Aspirin (acetylsalicylic acid) and/or pyrazoles interact with oral anticoagulants, oral antihyperglycaemic agents and the anticonvulsants phenytoin and valproic acid (sodium valproate). Elevation of blood concentrations of these agents can be potentially dangerous. Similarly, NSAIDs interact with digoxin. This interaction is most likely to occur in the elderly, in neonates or in patients with renal impairment. Indomethacin can influence the blood concentrations of aminoglycosides in neonates. Unfortunately, this effect seems unpredictable, so practical therapeutic recommendations cannot be made. When NSAIDs are combined with salicylates or diflunisal, the blood concentrations of the salicylate or diflunisal may increase. However, the clinical relevance of this increase in drug concentration seems to be of minor importance. Gastrointestinal bleeding caused by NSAIDs is the most dangerous when it results from a mixed pharmacokinetic/pharmacodynamic interaction; however, patients are also at risk when pharmacodynamic interactions only are involved.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1992

Ad hoc tracing of a cohort of patients exposed to acitretine (Neotigason) on a nation-wide scale.

Etretinate has been detected in the blood of women taking acitretine. Because of the proven teratogenic effects of etretinate it was decided to try to trace all users of acitretine in The Netherlands via all drug dispensing outlets (1450 community pharmacies, 95 hospital pharmacies and 636 general practitioners). A request for information on the date of birth, sex, type of prescriber, and the number of capsules dispensed yielded a response rate of 87%. In 61% of all the responding dispensing outlets a prescription for acitretine had been filled. Of these 1153 outlets, 40% had dispensed acitretine to one patient and 52% had dispensed it to 2-5 patients. The 2717 patients comprised 1500 men (55%) and 1217 women, with mean ages of 48 and 53 y, respectively. As against 45% of all the male users, 31% of all the women were in the child-bearing age (15-45 y). The average numbers of dispensed capsules was 167 to users of 10 mg capsules, and 107 to users of the 25 mg capsules. In more than 80% of cases acitretine had been prescribed by dermatologists. Because the large majority of inhabitants in The Netherlands use one community pharmacy, and because most of them have automated records, it is possible to trace a cohort of users quickly and almost completely. Because most large-scale problems with adverse reactions are discovered within the first 2 years of marketing, at a time when exposure and morbidity registries are still collecting information, ad hoc formation of a cohort in this way may be a useful resource for postmarketing surveillance.

Acitretin↗
PubMed1991

[Acute circulatory shock following administration of the non-regular enzyme preparation Wobe-Mugos].

A 54-year-old female patient was treated by a homoeopathic physician with non-orthodox enzyme therapy because of complaints pointing to multiple sclerosis. The therapy consisted of courses of German enzyme preparations (Wobe-Mugos injections, Wobenzym tablets and Wobe-Mugos suppositories), each of which lasted three weeks. During the third course the patient developed a circulatory shock immediately following an injection. She recovered successfully in hospital. On inquiry it became evident that symptoms of tightness, light-headedness and dry mouth had already occurred after a previous injection. In connection with this case a table is presented which reviews the alternative therapies that have been associated with anaphylactic or anaphylactoid reactions.

Anaphylaxis↗
PubMed1991

[Toxic damage of kidney, liver and muscle attributed to the administration of germanium-lactate-citrate].

The case history is described of a woman aged 57 years with renal, hepatic and muscular damage attributed to intake of germanium lactate-citrate (a cumulative dose of 32.1 g germanium) over at least one year, as alternative treatment of metastatic breast cancer. Histological examination of biopsies showed highly vacuolated cytoplasm of the epithelial cells of the distal renal tubules and micro- and macrovesicular steatosis of centrilobular hepatocytes. After discontinuation of the germanium, serum aminotransferases and creatine kinase values returned to normal, but moderately severe renal impairment persisted.

Breast Neoplasms↗
PubMed1991

[Acitretin; an example of ad-hoc tracing of users in acute problems with drugs].

Recently etretinate was demonstrated in the blood of women on acitretin. Because of the proven teratogenic effects of etretinate we tried to trace all users of acitretin in the Netherlands via all drug dispensing outlets (1450 community pharmacies, 95 hospital pharmacies and 636 general practitioners). A request for information as regards date of birth, sex, type of prescriber, and number of dispensed capsules was followed by a response rate of 87%. In 61% of all responding outlets a prescription of acitretin had been filled. Of these 1153 outlets 40% had dispensed the drug to one user, whereas 52% had dispensed acitretin to 2-5 patients. The 2717 patients consisted of 1500 men (55%) and 1217 women with mean ages of 48 and 53 years, respectively. Of the women 31% were in the age-group of 15-45 years and of the male users, 45% (p less than 0.0001), whereas in other age groups there was no difference. In 80% of cases acitretin had been prescribed by dermatologists. This study demonstrated that it is possible to trace a cohort of users quickly and almost completely. As most large-scale problems with adverse reactions are discovered in the first 2 years of marketing when exposure and morbidity registries are still collecting information, ad hoc cohort formation may be a useful resource for postmarketing surveillance.

Acitretin↗