PubMed Health⌕ Search

Biomedical subjects

M C Cornel

Publications and source records attributed to M C Cornel.

At least 55 records · Page 3Linked to original sources
PubMed1995

The role of pharmacists in the recruitment of a cohort for postmarketing surveillance. A case study of acitretin in The Netherlands.

In October 1990, a recall procedure was issued regarding the drug acitretin. The recommended post-therapy contraception period after acitretin therapy was extended from 2 months to 2 years. For a postmarketing surveillance study, we recruited a cohort from the source population of women aged 15-45 years who were exposed to acitretin. Recruitment occurred through dermatologists, and pharmacists plus dispensing general practitioners. We describe the speed of and the response to the recruitment procedures, and the representativeness of the recruited cohort. We also studied whether the individuals who gave informed consent would have preferred to be recruited by either dermatologists or pharmacists, and whether the information obtained from pharmacists and dispensing general practitioners was valid. This study revealed that pharmacists and dispensing general practitioners (drug dispensers) recruited their subjects rapidly, with no or little selection; they attained a 42% response. Dermatologists recruited their subjects slowly and selectively; they attained a 24% response. The majority of women (60%) recruited by dermatologists would have given their informed consent if they would have been recruited by their pharmacists. Drug dispensers are essential contributors to the recruitment of a study population. We do advise that such recruitment for a postmarketing surveillance study occurs by means of a collaboration between pharmacists and physicians.

Acitretin↗
PubMed1994

[Incidence and prevalence of genetically-determined disorders in The Netherlands; a literature study].

OBJECTIVE: To analyse if data now available on frequencies of genetic disorders are sufficient to be used in future as indicators when an evaluation of new developments is desired for policy-making purposes. DESIGN: Literature study. SETTING: The Netherlands. METHOD: Using automated literature search systems, papers published before October 1991 were surveyed and an inventory of incidence and prevalence of genetic disorders in the Netherlands was made. RESULTS: Depending on the pattern of heredity differences in available data and their validity were found. Valid data on most of the II congenital anomalies investigated were available from the EUROCAT registration in the northern Netherlands. This method of data collecting is also suitable for the evaluation of prevalence development. On the 29 multifactorial diseases occurring later in life that were investigated many data were available, although the varying sources made comparison difficult. These data were often out of date and had a highly varying validity. Of 3 chromosomal abnormalities the prevalence at birth was known. Of only 22 out of 650 monogenic disorders, described in the Netherlands up to 1991, the prevalence at birth and(or) in the population was known. CONCLUSION: Data on frequency of genetic disorders can be collected but the information now available is insufficient to serve as an indicator for government policy. Frequencies should also be considered in relation to the impact of the disease on the individual, his environment and society.

Adolescent↗
PubMed1994

Variation in prenatal cytogenetic diagnosis: policies in 13 European countries, 1989-1991. EUROCAT Working Group. European Registration of Congenital Anomalies.

The livebirth prevalence of autosomal chromosomal anomalies is determined by several factors, including maternal age distribution and the impact of prenatal cytogenetic diagnosis (PCD). The impact of PCD varies between countries, as the indications and the uptake vary. In a previous study we described differences in Down syndrome prevalence and the proportion of older mothers. We have now made a survey of the official PCD policies in 25 regions in 13 European countries for the period 1989-1991. In two countries, termination of pregnancy was not available. In the other 11 countries, international agreement existed on five indications: advanced maternal age, a previous child with a chromosomal anomaly, parents who are carries of a balanced translocation, mothers who are carriers of an X-linked disorder, and malformations at ultrasound. The exact limit for advanced maternal age varied from 35 to 38 years. There was a considerable variation for the indications advanced paternal age, amniocentesis for AFP or DNA, parental anxiety, a previous child with a congenital anomaly, abnormal maternal serum markers, and exposure to radiation/chemotherapy. The PCD uptake for mothers above the maternal age limit varied from 10 to 88 per cent. International harmonization of the indications for PCD is not considered feasible at present, because of the rapid changes in PCD policies even within countries.

Abortion, Induced↗
PubMed1994

Communicating a drug alert. A case study on acitretin in The Netherlands.

In October 1990, a recall procedure was initiated for the teratogenic drug acitretin, and the recommended post-therapy contraception period after acitretin therapy was extended from 2 months to 2 years due to the possibility of its conversion to the lipophilic compound etretinate. The aim of the present study was to evaluate the communication procedures and their effects as a drug alert from the health authorities, the pharmaceutical company and professional associations of health professionals to the population at risk. A model was used to evaluate communication between three hierarchical levels. Data were obtained via semi-structured interviews and structured questionnaires. Communication procedures were evaluated according to channel characteristics and by analysis of their contents. The effect was measured as whether the drug dispensers identified acitretin users, contacted physicians, and whether physicians communicated in person with the population at risk. The penetration of direct mail from the health authorities and from the pharmaceutical company ranged from 97-98% and 65-94% at Level 2 (health professionals). The population at risk was informed via personal communication with health professionals, and/or the mass media. Of the women at risk, 19% were contacted by a dermatologist, 30% by their GP, and 39% by the pharmacist. 35% was never informed by any health professional. The Dutch health care system is adequately equipped for effective communication between health authorities, pharmaceutical industry and health professionals.(ABSTRACT TRUNCATED AT 250 WORDS)

Acitretin↗
PubMed1994

Inability to detect plasma etretinate and acitretin is a poor predictor of the absence of these teratogens in tissue after stopping acitretin treatment.

1. Concentrations of etretinate, acitretin and its main metabolite 13-cis-acitretin were measured in plasma and subcutaneous fat samples from 37 women of childbearing age exposed to acitretin before November 1990. Twenty of the women still used acitretin and 17 had stopped therapy for a period ranging from 1 to 29 months. 2. The prevalences of detectable etretinate concentrations were 45% and 83% in plasma and subcutaneous tissue, respectively, among current acitretin users and 18% and 86% among those who had stopped acitretin therapy. Thus, inability to detect plasma etretinate is a poor predictor of the absence of etretinate in fat. 3. Acitretin and/or etretinate were detectable in fat and in some cases in plasma from women who had ceased acitretin therapy for up to 29 months. 4. We suggest that (cis)-acitretin and etretinate should be monitored in subcutaneous tissue when plasma measurements are negative. The recommended contraception period of 2 years after cessation of acitretin therapy should be reconsidered to avoid the risk of teratogenicity.

Acitretin↗
PubMed1993

Acardius acephalus after induced ovulation: a case report.

An excess of structural defects occurs in monozygotic twins compared to dizygotic twins or singletons. Among these defects the acardius acephalus or chorangiopagus parasiticus is one of the most rare and severe and a possible cause of pathology to the other twin. Ovulation induction by clomiphene causes an increased frequency of multiple gestation and possibly of monozygotic multiple pregnancy. In the present report, we describe a prenatally diagnosed and autopsied case of acardius acephalus from a pregnancy established after ovulation induction by clomiphene. Approximately 1.4% of pregnancies are accomplished after use of ovulation inducing medication in the Netherlands. A possible etiological role of clomiphene justifies close monitoring of future cases.

Abnormalities, Multiple↗
PubMed1993

Down syndrome: effects of demographic factors and prenatal diagnosis on the future livebirth prevalence.

In northwest European countries maternal age is increasing. This will lead to an increase of the prevalence of Down syndrome conceptuses. Meanwhile, the increased use of prenatal cytogenetic diagnosis (PCD) will lead to a decrease in the prevalence of Down syndrome among livebirths. We were interested to know what the result of these two opposite developments would be in the near future, and we describe here a model to quantify these processes and the resulting livebirth prevalence of Down syndrome. The model is demonstrated for The Netherlands from 1992 to 2001. The predicted livebirth prevalence for The Netherlands in 1992 is 1.36 per 1000. Demographic factors will cause an increase to 1.76 per 1000 in 2001 with present indications for PCD and a utilization ratio of 50%. An increase of the utilization ratio to 90% in 2001 will lead to a prevalence of 1.22 per 1000, a little less than the present prevalence. Alternative screening programs, including maternal serum screening, could lead to a further decrease of the livebirth prevalence. The model described here can be used for evaluation of the consequences of alternative forms of Down syndrome screening.

Birth Rate↗
PubMed1992

Acitretin (Neotigason). A review of pharmacokinetics and teratogenicity and hypothesis on metabolic pathways.

Acitretin was introduced as a replacement for etretinate, the ethyl ester of acitretin. Acitretin is eliminated at a much faster rate than etretinate. Although both drugs are teratogens, the replacement was important especially as it allowed for a much shorter post-medication period in which pregnancy should be precluded. Recent findings showed the presence of etretinate in the plasma of acitretin-treated patients. This article gives a review of known metabolic pathways of the retinoids and tries to elucidate the possible conversion of acitretin into etretinate after acitretin ingestion.

Abnormalities, Drug-Induced↗
PubMed1992

Comparison of couples referred and not referred for genetic counseling in a genetic clinic after the birth of a child with a congenital anomaly: a study in a population in the northeastern Netherlands.

After the birth of a child with a congenital anomaly, parents have many questions about cause, prognosis, and recurrence risk. An important means of transmitting such information is referral to a genetic clinic. We were interested in knowing what determines whether or not parents are referred for genetic counseling. Data from the local registration of congenital anomalies in the northeastern Netherlands (birth years 1981-1986; 1,217 children/fetuses) and data of the local genetic clinic were compared. The parents of 204 cases (16.8%) had been referred for genetic counseling. Of the couples referred, 76% were referred within one year after birth, usually by a pediatrician (48%). Parents of children with a single anomaly, recognized syndrome, or multiple anomalies not recognized as a syndrome were referred in 5%, 43%, and 26% of cases, respectively. Parents of liveborn children who died were referred in 38% of cases, parents of liveborn/still-alive and stillborn children in 13% and 22%, respectively. Previous affected sibs and absence of previous livebirths increased the likelihood of referral.

Congenital Abnormalities↗
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↗
PubMed1992

Spectrum of neural-tube defects in 34 infants prenatally exposed to antiepileptic drugs.

We analyzed the spectrum of neural-tube defects associated with maternal exposure to antiepileptic drugs (AEDs) and the possible contribution of familial and genetic factors to epilepsy or neural-tube defects. No specific association with maternal family history of neural-tube defects or epilepsy was seen. The ratio of spina bifida to anencephaly (33:1) suggested a specific association with caudal defects. Hydrocephaly was documented in at least 21 cases. Other midline defects, all associated with valproate (VPA), were hypospadias (two), hypertelorism (two), partial agenesis of corpus callosum, agenesis of septum pellucidum with lissencephaly of medial sides of occipital lobes, Dandy-Walker anomaly, and ventricular septal defect. This study shows that most neural-tube defects following maternal VPA use are severe open defects. They are frequently complicated by hydrocephaly and other midline defects. Prenatal diagnosis is possible.

Anticonvulsants↗
PubMed1991

[Prevalence at birth of more than 30 congenital disorders in Northern Netherlands].

For birth years 1981-1986, 1251 children/foetuses with congenital anomalies were reported to the regional EUROCAT registration of the northern Netherlands (2.5% of all live and stillbirths). In this article the total birth prevalence for over 30 individual congenital anomalies is presented for the first time in the Netherlands. The prevalence registered for neural tube defects is higher than in EUROCAT-centres elsewhere in continental Europe. The prevalence of cleft lip with or without cleft palate is, as in Denmark, higher than in other EUROCAT-centres.

Cleft Lip↗
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↗