Prescription drug use before and during pregnancy in a Medicaid population

The use during pregnancy of prescription, over-the-counter, and alternative medications among Hispanic women

BACKGROUND

Despite lack of scientific evidence about the safety of complementary and alternative medicines, the reported use of such remedies during pregnancies has increased. This study was undertaken to investigate the use of herbs, vitamins, and over-the-counter and prescription medications among pregnant Hispanic women and reasons for use, and to assess physician-patient level of communication about women's use.

METHODS

A total of 485 Hispanic women were surveyed by means of a self-administered questionnaire immediately postpartum in a public hospital in Houston, Texas. The primary outcome was use of alternative therapies during the prenatal period.

RESULTS

During their pregnancies, 19 percent of the participants took herbs and 47 percent took vitamin supplements, other than prenatal vitamins. The most common reason for using herbs and vitamins was to improve the woman's general health and energy level (59%); a few women (12%) had used them for specific pregnancy-related problems. Overall, 77 percent took prenatal vitamins and 21 percent supplemented with folic acid. The rates of use of over-the-counter and prescription medications were 23 and 29 percent, respectively. The use of prescription medication was two-and-a-half times higher among women with history of medical problems (adjusted OR = 2.59, 95% CI = 1.59-4.25, p = 0.0001). No other factor studied was independently associated with supplement or medication use. One in five women (20%) believed that herbs and vitamins were safer to use than prescription medication or were better at treating medical problems than prescription medicine, and one-third had not disclosed information about supplement use to their physicians.

CONCLUSIONS

Use of herbal remedies does not appear to be a replacement for conventional medicine among most pregnant Hispanic women. Patient education about the risks of alternative therapies may lead to a reduction in intake of alternative medicines and greater disclosure to medical practitioners among this ethnic group.

Antibiotics potentially used in response to bioterrorism and the risk of major congenital malformations

This study was designed to assess the association between pregnancy-related exposures to antibiotics recommended for use in the event of a bioterrorism attack and major congenital malformations. A retrospective cohort study included 30 049 infants from Tennessee Medicaid born between 1985 and 2000 identified from computerised state databases. Infants with fetal exposures to ciprofloxacin, azithromycin, doxycycline and amoxicillin (antibiotics recommended for potential bioterrorism attacks) (n = 24 521) and erythromycin (included as a positive control) (n = 2128) were compared with infants with no fetal exposure to any antibiotics (n = 3400). Major congenital malformations identified from computerised records were confirmed through medical record review. Overall, 869 (2.9%) of infants in the cohort had a confirmed major congenital malformation, with major malformations ranging from 2.5% to 3.0% among the antibiotic-specific exposure groups. No increased risk was present in multivariable analyses for any malformations and for malformations of specific organ systems. In conclusion, these data suggest that ciprofloxacin, azithromycin, doxycycline or amoxicillin use by pregnant women should not result in a greater incidence of overall major congenital malformations in infants whose mothers take these medications, though a large increase in risk cannot be ruled out.

Adequacy of prenatal care as a major determinant of folic acid, iron, and vitamin intake during pregnancy

This study aimed to quantify the association between adequacy of prenatal care and prevalence of folic acid, iron, and multivitamin intake during pregnancy. Data were obtained on socio-demographics, prenatal care, pregnancy complications, and use of vitamin/mineral supplements for 836 women, using a postpartum interview. Associations with the use of vitamin/mineral supplements were quantified with risk ratios (RR), computed by generalized binomial regression. A high proportion of women reported the use of folic acid (81.9%), iron (55.4%), and multivitamins (76.2%) as supplements during pregnancy. Use of supplements was independently associated with adequacy of prenatal care (adequate vs. inadequate: folic acid, RR = 2.28; 95%CI: 1.58-3.29; iron, RR = 1.99; 95%CI: 1.57-2.52, multivitamins, RR = 1.97; 95%CI: 1.54-2.51). Higher schooling was also associated with increased use of folic acid (RR = 1.42; 95%CI: 1.18-1.70), but not multivitamins (RR = 0.87; 95%CI: 0.77-0.98). Use of folic acid was less prevalent in single women (RR = 0.67; 95%CI: 0.48-0.95) and during unplanned pregnancies (RR = 0.81; 95%CI: 0.71-0.92). Adequacy of prenatal care is a major determinant of vitamin/mineral intake during pregnancy.

Gastroesophageal reflux disease in pregnancy

Gastroesophageal reflux disease during pregnancy is common. Altered structure and function of the normal physiological barriers to reflux of gastric contents into the oesophagus explain the high incidence of this problem in pregnant women. For the majority of patients, life-style modifications are helpful, but are not sufficient to control symptoms and medication is required. The optimum management of reflux in pregnant patients requires special attention and expertise, since the safety of the mother, foetus and neonate remain the primary focus. Gastroenterologists and obstetricians should work together to optimise treatment. Typically, one utilises a step-up program that starts with life-style modifications and antacids. If those methods fail, histamine-2 receptor antagonists and proton pump inhibitors are tried. Rarely, promotility agents are used. Initiation of these medications must be undertaken after a careful discussion of risks and benefits with patients. In patients without a prior history of reflux, symptoms usually abate after delivery.

The Use of Microdialysis for the Study of Drug Kinetics: Central Nervous System Pharmacokinetics of Diphenhydramine in Fetal, Newborn, and Adult Sheep

The central nervous system (CNS) pharmacokinetics of the H(1) receptor antagonist diphenhydramine (DPHM) were studied in 100- and 120-day-old fetuses, 10- and 30-day-old newborn lambs, and adult sheep using in vivo microdialysis. DPHM was administered i.v. at five infusion rates, with each step lasting 7 h. In all ages, cerebrospinal fluid (CSF) and extracellular fluid (ECF) concentrations were very similar to each other, which suggests that DPHM between these two compartments is transferred by passive diffusion. In addition, the brain-to-plasma concentration ratios were >or=3 in all age groups, suggesting the existence of a transport process for DPHM into the brain. Both brain and plasma DPHM concentrations increased in a linear fashion over the dose range studied. However, the ECF/unbound plasma and CSF/unbound plasma DPHM concentration ratios were significantly higher in the fetus and lambs (approximately 5 to 6) than in the adult (approximately 3). The factors f(CSF) and f(ECF), the ratios of DPHM areas under the curves (AUCs) in CSF and ECF to the plasma DPHM AUC, respectively, decreased with age, indicating that DPHM is more efficiently removed from the brain with increasing age. The extent of plasma protein binding of the drug increased with age. This study provides evidence for a transporter-mediated mechanism for the influx of DPHM into the brain and also for an efflux transporter for the drug, whose activity increases with age. Moreover, the higher brain DPHM levels in the fetus and lamb compared with the adult may explain the greater CNS effects of the drug at these ages.

Risk management and monitoring methods for the future mother, embryo, fetus, and post-natal consequences

Data required to asses the risk of a new drug regarding the normal course of pregnancy as well as embryo, fetal and neonate development, are often missing when a new product is launched. In such a situation, a risk management plan is to be developed by the industrial and validated by regulatory authorities. This risk management plan is to take into account the data benefits on the drug and its potential therapeutic use by women as being of childbearing age. The obtaining of post licence human data is to be built on many players, both private and public, involved in the data collection and evaluation. The setting up of such a network would allow them to join together and optimize their action by standardizing the data collected and their follow up. This should help to generate or rapidly respond to an alert, to conduct collaborative pharmacovigilance pharmacology studies.

Cardiovascular drug therapy in women

Cardiovascular disease has been the leading cause of morbidity and mortality in American women; yet, until recently, there was no mandate to specifically include women in clinical trials of the major cardiovascular drugs. Despite new regulations, there is still a lack of readily available data for the clinician to use when planning drug therapy for women, as many of the drugs in use today were developed and tested prior to the new regulations being in effect. The purpose of this article is to provide advanced practice nurses with the most current information on the use of cardiovascular drugs in women. Information on the unique biological features of women is first presented to provide background material for subsequent sections. This is followed by an explanation of pharmacokinetic processes in women to include information on absorption, distribution, and clearance of drugs. A brief review of the effects of the phases of the menstrual cycle on drug therapy is given and then issues related to the profound physiologic changes in pregnancy and subsequent effects on drug therapy are reviewed. An analysis of the strength of the available evidence on drug therapies in women from the major trials on acute coronary syndromes, heart failure, dyslipidemia, atrial fibrillation, and hypertension is provided. Finally, implications for practice, including recommendations for drug prescription, are summarized.

National patterns of medication use during pregnancy

PURPOSE

To describe patterns of medication use during pregnancy in ambulatory care settings according to the U.S. Food and Drug Administration (FDA) pregnancy risk classification.

METHODS

A cross-sectional study of two national ambulatory care surveys, sampling all office visits made by pregnant women in 1999 and 2000, was conducted. Using the FDA pregnancy risk classification, patterns of medication use and predictive factors for FDA pregnancy risk D or X (D/X) medications were evaluated.

RESULTS

In 1999 and 2000, about half of all pregnant visits had one or more medications. Among the total visits, FDA Class A was the majority (private = 65.7%; hospital = 79.5%; p < 0.05) followed by Class C (private = 26.5%; hospital = 36.4%; p < 0.05). Class D/X medications accounted for 6.4% and 2.9% of visits in private and hospital, respectively (p < 0.05). Medications with unknown pregnancy categories were predominant in the private setting (12.0% and 3.9%; p < 0.05). Age, insurance type, region, physician specialty, and number of medications were associated with a category D/X prescription. Among hospital visits, those from the West region and with private insurance were more likely to receive category D/X prescriptions. Number of medications was strongly associated with high-risk drugs in both settings.

CONCLUSIONS

This study shows considerable medication use among pregnant women. The prevalence of visits with FDA pregnancy category D/X drugs was moderate, but still indicates exposure to high-risk medications.

Use of Coptidis Rhizoma and foetal growth: a follow-up study of 9895 pregnancies

PURPOSE

To explore the effect of Coptidis Rhizoma on foetal growth in pregnancy.

METHODS

During 1985-1987, each pregnant woman with 26 or more weeks of gestation who came to the Taipei Municipal Maternal and Child Hospital for prenatal care was enrolled and interviewed by three trained interviewers using structured questionnaires to obtain detailed information including the herbal medicines used during pregnancy. Medical histories of diabetes, hypertension, antepartum haemorrhage and medicines used during pregnancy were abstracted from medical records of mothers'. Data of birth weight, gestational duration and characteristics of infants were gathered from the Taiwan national birth registration. A total of 9,895 singleton livebirths were analysed. The variables related to foetal growth included two dichotomous measures: low birth weight (LBW) and small for gestational age (SGA); and one continuous measure: birth weight. Potential risk factors associated with these outcomes were investigated using multiple logistic and linear regression models.

RESULTS

After adjustment, pregnant women taking Coptidis Rhizoma during pregnancy had no significantly adverse effect on foetal growth. There was a non-significantly slightly decreased mean of birth weight and increased risk of LBW and SGA babies if the frequency of using Coptidis Rhizoma was more than 56 times.

CONCLUSIONS

The usual usage of Coptidis Rhizoma during pregnancy seemed not to increase the adverse risk on foetal growth. Future observations for use of longer than 56 times or a higher cumulated dose were needed to clarify the safety.

Antibiotics in pregnancy: analysis of potential risks and determinants in a large German statutory sickness fund population

PURPOSE

Antibiotics are frequently prescribed drugs in pregnancy. The purpose of the study was to analyse the use, the potential risks and the determinants of systemic antibiotic prescriptions during pregnancy.

METHODS

A large, nation-wide acting German statutory sickness fund provided prescription data and personal data of 41,293 pregnant women. For this study, all prescriptions of systemic antibiotics (ATC: J01) dispensed to each woman during a 21-month period were analysed. We used the FDA risk classification system and enrolled a literature search to identify potentially harmful antibiotics. To investigate the impact of geographical and socio-economic determinants in antibiotic prescribing, a multivariate logistic regression model was performed.

RESULTS

Of the 41,293 women, 19.7% received at least one antibiotic drug during pregnancy. There was a shift to relatively safe and reduced antibiotic drug use during pregnancy. Prescribing of contraindicated antibactericals or potentially harmful drugs was seen in 521 women (1.3% of all women). In the logistic regression, being younger than 21 years (adjusted OR 2.14, 95%CI 1.80-2.53) or being welfare recipient (adjusted OR 1.57, CI 1.25-2.00) was strongly associated with higher antibiotic use. Significantly lower antibiotic use was seen in 5 of 16 German federal states (OR 0.74-0.83).

CONCLUSIONS

About 20% of pregnant women received antibiotics, and 1.3% received a harmful drug. To minimise the risks, detailed guidelines are needed for the antibiotic treatment during pregnancy.

Correlates of prescription drug use during pregnancy

PURPOSE

To evaluate the extent of prescription drug use and the use of category D or X drugs during pregnancy and examine the maternal characteristics associated with use.

METHODS

Medical record and survey data from an observational cohort of pregnant women from 2001 to 2003 (n=1626) were analyzed to examine the use of prescription drugs and the use of category D or X drugs.

RESULTS

A majority of these pregnant women were prescribed a prescription drug (56%), and 4% of women were prescribed a category D or X drug. The most common classes of medications prescribed were antibiotics (62%), analgesics (18%), asthma medications (18%), and antiemetics (17%). After adjustment for sociodemographic and clinical characteristics, African American women were more likely to use a prescription drug than white women. Lower levels of educational attainment were also associated with greater use of prescription drugs compared with women who had graduated from college. Women with a chronic health condition, gestational diabetes, a prenatal hospitalization, a history of infertility, or symptoms of acid reflux were also more likely to use a prescription drug than women without these conditions. Nulliparous women and women who were married or living with a partner were less likely to use category D or X drugs during pregnancy than women without these characteristics. Women with a history of infertility and those with a chronic health condition were more likely to use a category D or X drugs during pregnancy than those without these conditions.

CONCLUSIONS

The common use of prescription drugs during pregnancy supports the importance of expanding the evidence about the risks and benefits of prescription drug use during pregnancy and suggests the need for systems to safeguard prescribing practices for women of reproductive age.

Drug intake behaviour of immigrants during pregnancy

OBJECTIVE

To assess differences between native Spanish and immigrant pregnant women in behaviour relating to the use of medications during pregnancy.

STUDY DESIGN

This cross-sectional study was carried out at the department of obstetrics and gynaecology of an acute-care teaching hospital in the city of Barcelona, Spain. A total of 1103 women who gave birth at the hospital during a 1-year period were enrolled in the study. Each woman was interviewed by a gynaecologist during her stay in hospital after delivery, with special reference to drug use during the pregnancy. Drug exposure was assigned to trimesters, and drugs were divided into therapeutic groups, while the women taking part were divided up by nationality, educational level, parity and age. Data were analysed using bivariate, multivariate, and cluster analyses.

RESULTS

Slightly over half (55.7%) of the women were native to Spain and 44.3% were immigrants of other nationalities. About a quarter, or 25.4%, of pregnant patients had not taken any drugs during their pregnancies. The most frequent drugs taken by the others were vitamins, which were used mostly by Spanish women, followed by analgesics, which were mostly taken by non-Spanish western women. The largest group who had taken folic acid was made up of non-Spanish western women, while the Asiatic patients had taken this in the smallest proportion of cases.

CONCLUSIONS

Spanish patients and immigrants from other western countries showed a similar behaviour in terms of drug intake during pregnancy, which was different from the behavioural patterns seen in pregnant patients from developing countries.

Evaluation of gestational age and admission date assumptions used to determine prenatal drug exposure from administrative data

OBJECTIVE

Our aim was to evaluate the 270-day gestational age and delivery date assumptions used in an administrative dataset study assessing prenatal drug exposure compared to information contained in a birth registry.

STUDY DESIGN AND SETTING

Kaiser Permanente Colorado (KPCO), a member of the Health Maintenance Organization (HMO) Research Network Center for Education and Research in Therapeutics (CERTs), previously participated in a CERTs study that used claims data to assess prenatal drug exposure. In the current study, gestational age and deliveries information from the CERTs study dataset, the Prescribing Safely during Pregnancy Dataset (PSDPD), was compared to information in the KPCO Birth Registry. Sensitivity and positive predictive value (PPV) of the claims data for deliveries were assessed. The effect of gestational age and delivery date assumptions on classification of prenatal drug exposure was evaluated.

RESULTS

The mean gestational age in the Birth Registry was 273 (median = 275) days. Sensitivity of claims data at identifying deliveries was 97.6%, PPV was 98.2%. Of deliveries identified in only one dataset, 45% were related to the gestational age assumption and 36% were due to claims data issues. The effect on estimates of prevalence of prescribing during pregnancy was an absolute change of 1% or less for all drug exposure categories. For Category X, drug exposures during the first trimester, the relative change in prescribing prevalence was 13.7% (p = 0.014).

CONCLUSION

Administrative databases can be useful for assessing prenatal drug exposure, but gestational age assumptions can result in a small proportion of misclassification.

Drug exposure in pregnant women

The objectives of this paper are to describe the Hungarian case-control surveillance system of congenital abnormalities (HCCSCA), to summarize the principles of this activity and our main experiences. Among the main principles, the importance of the time factor (the first trimester concept is outdated), the differentiation of isolated and multiple manifestations of the seemingly same congenital abnormalities, noxa specificity, the separation of drugs and pregnancy supplements within medicinal products (or medicines) are stressed. After some methodological problems (recall bias, chance effect), the main experiences regarding the risk and benefit of medicines are summarized. The conclusion is that the results of our studies based on the data set of the HCCSCA showed that at present the exaggerated teratogenic risk of drugs is much more harmful for the fetus than the real teratogenic effect of some drugs themselves. Medical doctors and other experts therefore need more education to know the principles and findings of modern human teratology because it may help us to have a better balance between the risk and benefit of drug use during pregnancy.

Fatores associados ao uso de medicamentos durante a gestação em seis cidades brasileiras

O objetivo deste estudo foi comparar o uso de medicamentos durante a gravidez, segundo variáveis sócio-demográficas, em gestantes que fizeram o pré-natal em serviços do SUS em seis grandes cidades brasileiras. Utilizando-se um questionário estruturado, foram entrevistadas 5.564 gestantes que se apresentaram para consulta em serviço de pré-natal do SUS, participantes do Estudo Brasileiro de Diabetes Gestacional, entre 1991 e 1995. O uso de qualquer medicamento mostrou uma associação positiva com o aumento da escolaridade, da idade e com o fato de ter companheiro, e uma associação negativa com maior número de filhos. O uso de medicamentos multivitamínicos e medicamentos que atuam sobre o aparelho digestivo mostrou aumento da associação com maior escolaridade e idade e uma associação negativa com o aumento do número de filhos. O uso de medicamentos antianêmicos mostrou uma associação negativa com o aumento da escolaridade e com o aumento da idade. O uso de multivitamínicos e medicamentos que atuam sobre o aparelho digestivo mostrou uma associação com variáveis que caracterizam gestantes de melhor nível sócio-econômico, sugerindo que o uso de medicamentos é uma expressão de cuidado com a gestação.

Prescription drug use in pregnancy

OBJECTIVE

The purpose of this study was to provide information on the prevalence of the use of prescription drugs among pregnant women in the United States.

STUDY DESIGN

A retrospective study was conducted with the use of the automated databases of 8 health maintenance organizations that are involved in the Health Maintenance Research Network Center for Education and Research on Therapeutics. Women who delivered of an infant in a hospital from January 1, 1996, through December 31, 2000, were identified. Prescription drug use according to therapeutic class and the United States Food and Drug Administration risk classification system was evaluated, with the assumption of a gestational duration of 270 days, with three 90-day trimesters of pregnancy, and with a 90-day period before pregnancy. Nonprescription drug use was not assessed.

RESULTS

During the period 1996 through 2000, 152,531 deliveries were identified that met the criteria for study. For 98,182 deliveries (64%), a drug other than a vitamin or mineral supplement was prescribed in the 270 days before delivery: 3595 women (2.4%) received a drug from category A; 76,292 women (50.0%) received a drug from category B; 57,604 women (37.8%) received a drug from category C; 7333 women (4.8%) received a drug from category D, and 6976 women (4.6%) received a drug from category X of the United States Food and Drug Administration risk classification system. Overall, 5157 women (3.4%) received a category D drug, and 1653 women (1.1%) received a category X drug after the initial prenatal care visit.

CONCLUSION

Our finding that almost one half of all pregnant women received prescription drugs from categories C, D, or X of the United States Food and Drug Administration risk classification system highlights the importance of the need to understand the effects of these medications on the developing fetus and on the pregnant woman.

[Drug prescription for pregnant women: a pharmacoepidemiological study]

Prescription drug use by pregnant women should be viewed as a public health issue, since there are numerous gaps in knowledge on the consequences for both the mother and the fetus. Pharmacoepidemiological studies can help minimize the inherent risks in drug treatment by establishing a profile of drug consumption during pregnancy, providing an evaluation of this service, and identifying intervention measures. The purpose of this study was to establish a prescription profile for pregnant women treated under the National Health System (SUS) in Piracicaba, São Paulo State, Brazil, using prescription indicators recommended by the World Health Organization and the U.S. Food and Drug Administration classification of medicines according to risk to the fetus. According to the current study, during prenatal consultations 44.7% of the women received drug prescriptions, and the most widely prescribed group of drugs were those acting on the hematopoietic system (34.9%). Of this total, 26.0% of the drugs were included in fetal risk category C, 1.5% in category D, and 1.5% in category E. These data point to the medicalization of pregnancy and the need for intervention measures aimed at rational prescription drug use during the prenatal period.

Prescription of drugs to pregnant women in France: the HIMAGE study

The HIMAGE study, conducted in partnership with the principal Public Health Insurance Funds of the Loire region, analysed medicinal prescriptions during pregnancy on the basis of a representative sample of 911 pregnant women resident in this region of France. Altogether 93.5% received at least one prescription, with a mean of 10.9 different drugs per woman. The prescriptions were predominantly for drugs of the following Anatomical Therapeutic Chemical (ATC) classes: "alimentary tract and metabolism" (78%); "genito-urinary system and sex hormones" (62%); "nervous system" (62%); and "blood and blood-forming organs" (57%). Iron supplements, paracetamol, folic acid, magnesium, progesterone, oxaceprol, phloroglucinol, amoxicillin, domperidone and diosmine were the most frequently prescribed drugs. In total, 4.6% of the women were exposed to drugs involving a risk during pregnancy: principally nonsteroidal anti-inflammatory drugs (NSAIDs) prescribed from the sixth month onwards. This study revealed a high frequency of prescription of drugs to pregnant women, largely motivated by non-rational and to some extent culture-specific considerations, and it also highlighted the prescription of drugs known to involve risk during pregnancy. These results provide a basis for advising clinicians on the rational and safe use of drugs during pregnancy.

Can We Ensure the Safe Use of Known Human Teratogens?

The prescription of known teratogenic medications requires a careful balance between allowing women access to medications that they might need and avoiding unnecessary exposure to these medications during pregnancy because of their devastating fetal effects. Isotretinoin, a potent human teratogen, is of particular concern because of its widespread use among reproductive-aged women and the dramatic increase in use from 1992 through 2000. A revised risk management system was implemented in 2002 because of concerns about the continued occurrence of isotretinoin-exposed pregnancies. However, the recent approval of three generic versions of isotretinoin in the US has further complicated risk management and raises concerns that use might increase further if the lower cost of generics serves to increase accessibility. There are now four separate isotretinoin risk management systems in the US, each with its own distinct packaging, though the requirements for and substance of each are identical. Some additional concrete steps could be taken to minimise any unnecessary use of isotretinoin and help allow an adequate assessment of the current risk management systems. In addition to being familiar with and following all aspects of the current risk management system, physicians could choose to limit the use of isotretinoin to those who meet the labelled indications in order to reduce the number of exposed pregnancies. All four companies currently marketing isotretinoin in the US could jointly and voluntarily establish a consolidated, mandatory registration and follow-up of all women of reproductive potential who receive an isotretinoin prescription. Mandatory registration has many challenges, but it could allow a clear accounting of the total number of women for whom follow-up information is and is not available. Although the companies cannot be legally compelled to use a consolidated approach, the use of a single registry for the originator's product and all generic brands would allow identification of duplicates and also avoid the confusion that is introduced by providing materials that not only look different, but also have different addresses, contact information and names for participation in follow-up surveys. This is particularly important because women might take more than one version of isotretinoin during a single course of therapy or might receive a different programme's materials from their doctor than from the pharmacy. Though the introduction of generic versions of isotretinoin further complicates risk management, the companies marketing isotretinoin have an opportunity to work together to demonstrate their commitment to both limit the occurrence of exposed pregnancies and conduct a meaningful evaluation of the occurrence of pregnancies exposed to isotretinoin.

Safe prescribing practices in pregnancy and lactation

Midwives and other health care providers face a dilemma when a pregnant woman develops a condition that usually is treated with a pharmacologic agent. Understanding of basic teratology associated with drugs as well as the FDA categorization of agents can assist professionals in recognizing which pharmaceuticals should be used or avoided. In addition to reviewing teratology, this article addresses the use of common drugs for the treatment of upper respiratory conditions, minor pain, gastrointestinal problems, psychiatric illnesses, and neurologic disorders. In each category, current evidence is presented pertaining to which agents should be recommended for pregnant women.

[Drug use by pregnant women in six Brazilian cities]

OBJECTIVE

To describe drugs used during pregnancy by women attending prenatal clinics of the national public health system (SUS) in Brazilian cities.

METHODS

Using a structured questionnaire, 5,564 pregnant women between the week 21 to 28 who attended prenatal visits of the SUS in six Brazilian cities were interviewed. The interview questions were grouped in "guided use" to cover pain, cramps, nausea, cough, and others, and "guided medicine" to cover vitamins, iron, and fluoride. The Food and Drug Administration gestational risk classification (1991-1995) was applied.

RESULTS

Of a total of 5,564 women, 4,614 (83.8%) used at least one drug during pregnancy, with a total of 9,556 drugs used. The drugs most frequently used were vitamins associated with anti-anemics (33.5%), gastrointestinal drugs (31.3%), analgesics and anti-inflammatory drugs (22.2%), anti-anemics (19.8%), and antibiotics (11.1%). Regarding gestational risk, 3,243 drugs used (34%) belonged to category A risk, 1,923 (22.6%) to category B, 3,798 (39.7%) to category C, 289 (3.0%) to category D, and 55 (0.6%) to category X.

CONCLUSIONS

A large variation in drug use across the cities was observed, especially for anti-anemics and vitamins associated with anti-anemics, revealing the lack of a national consensus regarding the use of these drugs during pregnancy. There was no literature data about safety during pregnancy for 12.9% of the drugs used. This percentage, plus the 26.9% of category C drugs, shows that 40% of the drugs used during pregnancy do not belong to the approved safety categories. However, only 3% of the 9,956 drugs used were clearly contraindicated during pregnancy.

Do pregnant women report use of dispensed medications?

Surveillance of drug safety in pregnancy often draws on administrative prescription registries. Noncompliance in the use of prescribed medication may be frequent among pregnant women owing to their fear of fetotoxic side effects. To estimate compliance in the use of prescription drugs dispensed during pregnancy, we compared prescription data from the North Jutland Prescription Database with information on drug use provided by pregnant women to the Danish National Birth Cohort (DNBC), which is a health interview survey. We used the North Jutland Prescription Database to identify all prescription drugs dispensed during pregnancy for the 2,041 women who were enrolled in the DNBC in the County of North Jutland, Denmark. Compliance was defined as the probability of reporting drug use in DNBC after purchasing a dispensed prescription drug. The overall compliance to drugs purchased within 120 days before the interview was 43% (95% confidence interval = 40-46). Drugs used for treating chronic diseases, for example, beta-blockers, insulin, thyroid hormones, and diuretic and antiepileptic drugs, were always reported to be used, but compliance was low for drugs used for local or short-term treatment such as antihistamines, antibiotics, antacids, nonsteroid anti-inflammatory drugs, and gynecologic drugs. Thus, for the latter drug groups the prescription database may provide an incomplete identification of exposure. Neither data source is unbiased regarding actual drug intake. Nevertheless, our results indicate that for some drug groups risk assessment studies based on prescription data may produce false negative results as a result of noncompliance.

Description and mission evaluation of the Hungarian case-control surveillance of congenital abnormalities, 1980-1996

BACKGROUND

The Hungarian Case-Control Surveillance of Congenital Abnormalities was established in 1980. This article describes how the Hungarian Case-Control Surveillance of Congenital Abnormalities was first organized and is currently maintained. The baseline statistics are provided and potential venues of postmarketing surveillance of drug teratogenicity and other public health tasks and research are proposed.

METHODS

Cases with congenital abnormalities and patient controls with Down syndrome were selected from the Hungarian Congenital Abnormality Registry. Population controls without congenital abnormalities were selected from the National Birth Registry on the basis of three matching criteria: sex, week of birth, and district of parent's residence. Three sources of information concerning drug exposures, maternal disorders, and pregnancy complications, among others, were used: (1) prospective and medically recorded data from antenatal care logbooks and discharge summaries; (2) retrospective maternal self-reported data obtained with a structured questionnaire in all the three study groups; and (3) data collected by regional nurse in house visits to nonrespondent cases and patient controls. Twenty-five congenital abnormality groups were evaluated. During the 17-year period of data collection, 22,843 cases, 38,151 population controls, and 834 patient controls were incorporated into the data set, constituting the largest population-based case-control data set of congenital abnormalities to date.

RESULTS

Demographic features of pregnant women and informative offspring are presented along with the distribution of 25 main groups of congenital abnormalities.

CONCLUSIONS

This system is appropriate for postmarketing the surveillance of drug teratogenicity, for the improvement of congenital abnormality diagnosis, to get informed consent, to have a communication with parents and to provide material for research.

Epidemiologic assessment of the safety of conventional nonsteroidal anti-inflammatory drugs

The use of conventional nonsteroidal anti-inflammatory drugs (NSAIDs) has been associated with upper gastrointestinal bleeding and perforation (UGIB), acute liver injury, acute renal injury, heart failure, and adverse reproductive outcomes. This article summarizes the effects of various factors, such as NSAID dose, duration of treatment, patient age, and ulcer history, on the incidences of these adverse side effects. We used the UK General Practice Research Database to study further the principal safety concern related to NSAIDs, namely, UGIB.

Pharmacokinetic changes during pregnancy and their clinical relevance

The dynamic physiological changes that occur in the maternal-placental-fetal unit during pregnancy influence the pharmacokinetic processes of drug absorption, distribution and elimination. Pregnancy-induced maternal physiological changes may affect gastrointestinal function and hence drug absorption rates. Ventilatory changes may influence the pulmonary absorption of inhaled drugs. As the glomerular filtration rate usually increases during pregnancy, renal drug elimination is generally enhanced, whereas hepatic drug metabolism may increase, decrease or remain unchanged. A mean increase of 8 L in total body water alters drug distribution and results in decreased peak serum concentrations of many drugs. Decreased steady-state concentrations have been documented for many agents as a result of their increased clearance. Pregnancy-related hypoalbuminaemia, leading to decreased protein binding, results in increased free drug fraction. However, as more free drug is available for either hepatic biotransformation or renal excretion, the overall effect is an unaltered free drug concentration. Since the free drug concentration is responsible for drug effects, the above mentioned changes are probably of no clinical relevance. The placental and fetal capacity to metabolise drugs together with physiological factors, such as differences acid-base equilibrium of the mother versus the fetus, determine the fetal exposure to the drugs taken by the mother. As most drugs are excreted into the milk by passive diffusion, the drug concentration in milk is directly proportional to the corresponding concentration in maternal plasma. The milk to plasma (M:P) ratio, which compares milk with maternal plasma drug concentrations, serves as an index of the extent of drug excretion in the milk. For most drugs the amount ingested by the infant rarely attains therapeutic levels.

Drug use in pregnancy: a comparative appraisal of data collecting methods

We have compared the reliability of the information about drug therapy and pregnancy retrieved by interviewing patients with that distilled from pharmacy records. In the initial phase of each interview we used the internationally accepted open-ended technique, and extended this with an indication-oriented set of questions and then a set of specific drug-oriented questions. These data were then compared with those from pharmacy records on dispensing for the same patients during their pregnancy. The results suggest that if drug consumption during pregnancy is evaluated by interview, one should not restrict oneself to open-ended questions but should include indication-oriented and, when appropriate, drug-oriented questions. Such specific questions offer the opportunity of detecting the use of over-the-counter medication and of constructing drug use/complaint profiles. By contrast, pharmacy records will give better information in case of long recall periods and in patients with multiple and/or repeated drug use. Investigators should use the complementary elements of both techniques where appropriate.

Use of prescription and non-prescription drugs in pregnancy. The Baltimore-Washington Infant Study Group

We analyzed use of therapeutic drugs during pregnancy by 2752 mothers of infants without major congenital malformations. During pregnancy, 68% of the women used at least one prescription or non-prescription drug. Drug use in pregnancy was significantly more common for women who were white, older, married, better educated, of higher income and occupational status, receiving private prenatal care and not living in urban areas. Number of maternal illnesses, higher socioeconomic status, white race, multiparity and use of recreational drugs explained 26% of reported drug use. The mean number of drugs reported (1.2) underestimates total drug exposure due to exclusion of some drug categories including multivitamins and illicit drugs. Since the majority of women giving birth to normal infants report use of at least one pharmacologic agent during pregnancy, attribution of adverse outcome to drug use in an individual case is rarely justified.

Transplacental and nonplacental clearances of diphenhydramine in the chronically instrumented pregnant sheep

Pharmacokinetic studies of the histamine H1-receptor antagonist diphenhydramine were conducted in eight chronically instrumented pregnant sheep at 126-138 days of gestation. Diphenhydramine was administered by simultaneous intravenous bolus injection and infusion to steady state given 48 h apart, to the ewe and the fetus on separate occasions. Average steady-state drug concentration in plasma after maternal infusion was 212.1 +/- 67.8 ng/mL in the mother and 36.3 +/- 14.4 ng/mL in the fetus, resulting in a fetal-to-maternal concentration ratio of 0.19 +/- 0.10. Following fetal infusions, maternal and fetal steady-state drug concentrations were 31.1 +/- 11.6 and 447.6 +/- 185.2 ng/mL, respectively. The free fraction of diphenhydramine determined in the fetus (0.277 +/- 0.087) was significantly greater than that in the mother (0.141 +/- 0.079). Transplacental and nonplacental clearances were calculated at steady state according to a general two-compartment open model, with drug elimination occurring from both compartments. The total fetal clearance (472.7 +/- 215.7 mL/min) was relatively small compared with the total maternal clearance (3426.1 +/- 905.8 mL/min). The transplacental clearance from fetus to mother (264.4 +/- 138.7 mL/min) was approximately threefold higher than that from mother to fetus (82.4 +/- 40.5 mL/min). Maternal nonplacental clearance (3343.8 +/- 890.7 mL/min) accounted for 97.8 +/- 1.1% of the maternal total clearance, whereas fetal nonplacental clearance (208.4 +/- 80.4 mL/min) accounted for 45.1 +/- 4.7% of the fetal total clearance. It is concluded that in the fetus both the transplacental and nonplacental pathways are important for drug elimination.

The use of low dose aspirin in pregnancy

Pregnancy-induced hypertension (PIH) in general and preeclampsia in particular are major causes of maternal and perinatal morbidity. Data from our studies and from a number of prospective controlled trials have suggested that aspirin in doses of 60-150 md/day during the second and third trimester reduces the risk of PIH and improves maternal and neonatal outcomes. The number of patients enrolled in these studies is relatively small. However, meta-analysis of existing trials suggests that low dose aspirin reduces the risk of PIH and severe low birth weight. Although no maternal or neonatal adverse effects associated with aspirin were observed, the use of aspirin in the third trimester has been reported to cause hemostatic abnormalities in both mother and neonate. Other complications associated with prostaglandin synthetase inhibitors include premature closure of the ductus and neonatal primary pulmonary hypertension. The use of aspirin in the first trimester is not associated with increased risk of structural malformations. On the basis of these findings and pending the results of ongoing large-scale randomized multicenter trials, we suggest that daily low dose aspirin (1 to 2 mg/kg/day) be recommended only for select women at high risk for developing PIH and its associated complications.

Effects of exposure to benzodiazepine during fetal life

Dysmorphism and mental retardation have been reported in 7 Swedish children born of mothers who had taken high doses of benzodiazepines regularly during pregnancy. To explore this association further, we examined benzodiazepine use during pregnancy in 104,000 women whose deliveries were registered by the US public health insurance system, Medicaid, during 1980-83. Fetal outcomes were assessed from the health claims profiles of their offspring, up to 6-9 years after delivery. 80 pregnant women had received 10 or more benzodiazepine prescriptions during the 4 years. Their records showed heavy general use of health care and frequent alcohol and substance abuse, and other disorders that could confound any effect of the benzodiazepines. For the 80 pregnancies, 3 intrauterine deaths were identified as well as 2 infants with congenital abnormalities whose curtailed records suggested neonatal death. Records of 64 surviving children could be linked to these 80 pregnancies whilst records for 11 apparent survivors could not be located. 6 of the 64 survivors had diagnoses consistent with teratogenic abnormalities. The high rate of teratogenicity after heavy maternal benzodiazepine use occurs with multiple alcohol and substance exposure and thus may not be due to benzodiazepine exposure.

Handling of risk-bearing drugs during pregnancy. Do we choose less risky alternatives?

The drug use of nearly 2,000 pregnant women was evaluated at the level of the individual patient for the drugs belonging to the Australian risk categories B3, C and D. The pattern of changes in the use of these drugs is studied in terms of women who discontinue (d), continue (c) or begin (b) using the drug during pregnancy. The ratios d/(c+b) and d/b were the highest for the drugs belonging to the high-risk groups and the lowest for drugs from the low-risk categories. This suggests a congruence between theoretical knowledge and daily practice. Patients who had already been using a drug for a long time before pregnancy, more frequently continued using that drug than patients who had been using the drug only incidentally before. The described daily dose for the riskful drugs was approximately 20% lower in patients who started to use a drug during pregnancy compared to those who continued drug use. The data from this analysis indicate that the prescribing physician is generally aware of the possible risks of drug use during pregnancy. The d/(b+c) and d/b ratios are shown to be a good measure of prescribing behaviour in relation to pregnancy and can be used to compare knowledge of theory and daily practice.

Prenatal exposure to prescribed drugs in Tennessee Medicaid, 1983-1988

This report describes the prenatal exposure histories of 107,804 women to prescribed drugs other than vitamins, iron and other minerals. The data were obtained from Tennessee Medicaid pharmacy files linked to birth and fetal death certificates for 1983-1988. The utility of these data to other investigators in predicting power or estimating sample size for studies of drug exposure in pregnancy associated with adverse birth outcomes is discussed.

Medication in early pregnancy: prevalence of use and relationship to maternal characteristics

Medication use was assessed in a population of 4186 women who were delivered of infants at Yale-New Haven Hospital, New Haven, Connecticut, between 1980 and 1982. The frequency of over-the-counter and prescription drug use, and the association of such use with maternal characteristics was studied. Of all women, 66% used at least one drug. The mean number of drugs used by all subjects was 1.3 and, among drug users, 2.9. Of all drugs used, 68% were over-the-counter and 32% were prescription preparations. Internal analgesics, autonomic drugs, antiinfective agents, and antacids were most frequently used. Women who used prescription drugs were also more likely to use over-the-counter medications. Maternal characteristics that were associated with an increase in both over-the-counter and prescription drug use were being white, smoking more than 20 cigarettes a day, using alcohol, using caffeine, and smoking marijuana. These findings suggest that women who engage in "risk-taking behavior" during pregnancy are also more likely to use medications while pregnant.

Investigating drug use in pregnancy. Methodological problems and perspectives

In this study the use of prescribed drugs before, during and after pregnancy is described. The study is based on data obtained from pharmacy records of 1,948 women who delivered a live-born infant. Different measures to evaluate drug exposure are used. During the nine months of pregnancy 86% of the women used on average 4.2 prescriptions. During the course of pregnancy the use of gastro-intestinal and blood-forming drugs increased, whereas the use of cardiovascular, antiphlogistic and central nervous system drugs decreased. Anti-emetics were predominantly used in the first trimester, and antacids in the last trimester, whereas laxatives were especially used after delivery. The percentage of women who used a treatment for vaginal infections increased from 2 to 7 during pregnancy. Most of the women (73%) received one or more iron prescriptions during the course of pregnancy, however, the prescribed daily dose was low (prescribed daily dose/defined daily dose = 0.6). At least 1% of the women filled a new prescription for anticonceptives in the first trimester of pregnancy. Most likely, our data reflect the general prescribing pattern for Dutch pregnant women who delivered a live-born baby. Therefore, they form a good and detailed base for further studies, for instance, on the exposure to drugs with known or suspected risks or on the use of drugs in patients with chronic concomitant diseases. Such studies may lead to recommendations that may improve prescribing behaviour.

Evaluation of drug intake during pregnancy in the Hungarian Case-Control Surveillance of Congenital Anomalies

The data of the Hungarian Case-Control Surveillance of Congenital Anomalies, 1980-1987, were evaluated concerning drug intake during pregnancy in 10,698 index patients, 21,546 negative controls, and 828 positive controls (Down syndrome). Excluding pregnancy supplements, the proportion of no drug use was about 30% and the mean number of drugs used was 2.0 in the negative control group. These figures did not differ significantly from data of study and positive control groups. The analysis of most commonly used drugs indicated an extremely high proportion of hormonal support therapy. The teratogenic effect of several human teratogenic drugs was confirmed. However, their use is relatively rare and their attributable risk within the etiology of congenital anomalies is low, at about 0.3-1.0%. At present the teratogenic risk of drugs in humans is exaggerated and it has several unfortunate consequences: negligence in necessary drug use, unnecessary anxiety in pregnant women, and termination of planned pregnancies without any reasonable cause.

Drug use in pregnancy: an overview of epidemiological (drug utilization) studies

The need for further information on drug utilization patterns during pregnancy in different countries was assessed by reviewing literature obtained by hand and computer searches for the years 1960-1988. The 13 identified studies showed that pregnant women used an average of 4.7 drugs. The most commonly ingested medications were vitamins and iron preparations (almost all women), analgesics, antiemetics and antacids. However, the important variables taken into account differently in each study, such as date of surveillance, country, size of population, personal habits, and physiopathological and demographic characteristics, may it impossible to construct a comprehensive, detailed, up-to-date picture of drug utilization during pregnancy. The evaluation confirmed the need for systematic permanent surveillance of drug utilization in pregnancy, so as to avoid the use of data based on widely differing contexts, times and methods, in a field where knowledge is often derived from scanty information.

The relation of aspirin use during the first trimester of pregnancy to congenital cardiac defects

It has been hypothesized that the ingestion of aspirin by women during pregnancy increases their infants' risk of certain congenital heart defects. Using data from a large program of case-control surveillance of congenital malformations, we evaluated this hypothesis. The case groups were made up of infants with any structural cardiac defect (n = 1381) and five selected cardiac defects (the subgroups were not mutually exclusive): aortic stenosis (n = 43), coarctation of the aorta (n = 123), hypoplastic left ventricle (n = 98), transposition of the great arteries (n = 210), and conotruncal defects (n = 791). First-trimester aspirin use among the mothers of these infants was compared with that among the mothers of a control group of infants with other malformations (n = 6966). The prevalence of any maternal aspirin use was similar for cases (25 to 33 percent) and controls (27 percent). The relative risks (and 95 percent confidence interval) among infants whose mothers were aspirin users as compared with those whose mothers did not use aspirin, adjusted for potential confounding factors, were 0.9 (0.8 to 1.1) for any cardiac defect, 1.2 (0.6 to 2.3) for aortic stenosis, 1.0 (0.6 to 1.4) for coarctation, 0.9 (0.6 to 1.4) for hypoplastic left ventricle, 0.9 (0.6 to 1.2) for transposition of the great arteries, and 1.0 (0.8 to 1.2) for conotruncal defects. Furthermore, no dose-effect pattern was identified. The findings of this study indicate that aspirin use during the first trimester of pregnancy does not increase the risk of congenital heart defects in relation to that of other structural malformations.

Potential human developmental toxicants and the role of animal testing in their identification and characterization

Some 50 chemicals have been identified from environmental, occupational, or therapeutic exposure data as being potential developmental toxicants in humans. The toxicity pattern of these chemicals in humans has been characterized and correlated with developmental toxicity end points in laboratory animal models in order to determine the relevance and predictiveness of the results of testing in animals in extrapolation to human data. In general, animal developmental toxicity data closely paralleled human outcomes, and while humans in most cases were more sensitive than animals, the data support the concept that, imperfections aside, studies in animals serve a vital role in the hazard identification process.

Maternal use of prescribed drugs associated with recognized fetal adverse drug reactions

To quantitate the frequency of exposure in pregnancy to selected drugs listed by the American Medical Association's Department of Drugs as having known or suspected association with fetal adverse drug reactions, we examined the prescription records of 18,886 Michigan Medicaid recipients who delivered a liveborn infant between April 1, 1981, and March 31, 1983. Focusing only on specific trimesters considered risk periods for each drug-fetal occurrence of adverse drug reaction, the use of tetracyclines during the first trimester of pregnancy was the most prevalent (21.3 exposed women/1000) prescribed drug associated with known or suspected fetal adverse drug reactions. The second most prevalent was phenobarbital in the first trimester, with 10.8 women exposed/1000. Following a close third was the use of the sulfonamides in the second trimester, with 10.0 women exposed/1000. The prescribing of nitrofurantoin and the sulfonamides in the last trimester and tetracyclines throughout pregnancy appears excessive. There are few indications for the outpatient use of the tetracyclines during pregnancy. Practitioners caring for pregnant women need to carefully evaluate the need for these drugs and consider when risks may outweigh benefits.