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Biomedical subjects

Gideon Koren

Publications and source records attributed to Gideon Koren.

At least 181 records · Page 10Linked to original sources
PubMed2003

Bioavailability of a pediatric amlodipine suspension.

Currently, a suspension of crushed tablets of amlodidpine is widely used in children with hypertension without knowledge of its bioavailability. A comparative bioavailability study of a tablet and suspension formulation of amlodipine was completed in 20 healthy adult volunteers. Bioequivalence of the suspension was not different from the tablets. These results support the use of the suspension in children who cannot take the tablet.

Adult↗
PubMed2003

Effects of aspirin consumption during pregnancy on pregnancy outcomes: meta-analysis.

BACKGROUND: We assessed the effects and safety of aspirin treatment during pregnancy on fetal and neonatal outcomes. METHODS: We searched MEDLINE (1966-2001), EMBASE (1980-2000), TOXLINE (1994-2000), EB M Cochrane Database of Systematic Reviews (1991-2000), Reproductive Toxicology (2001), teratology texts, and bibliographies of all the included studies. We looked for published randomized controlled studies reporting aspirin treatment to improve outcomes of moderate- and high-risk pregnancies. The key words used to search for articles about exposure to aspirin were salicylic acid, pregnancy, and pregnancy complications; key words used to search for outcome were neonatal diseases and abnormalities. Based on our search strategy, 1904 citations were identified; their titles and abstracts were reviewed by one reviewer. Of these citations, 182 papers were selected for detailed review. Two reviewers independently determined whether a study should be included in the final analysis. In cases of disagreement, the decision was based on the assessment of a third reviewer. RESULTS: Data were extracted independently by each reviewer. We calculated the pooled relative risk (RR) or weighted mean difference and 95% confidence intervals (CI), assuming a random-effect model. Thirty-eight studies met the inclusion criteria. The risk for miscarriage did not differ between women treated with aspirin andplacebo (seven studies; RR, 0.92; 95% CI, 0.71-119). Women who took aspirin had a significantly lower risk of preterm delivery than did those treated with placebo (22 studies; RR, 0.92; 95% CI, 0.86-0.98). There was no significant difference in perinatal mortality (20 studies; RR, 0.92; 95% CI, 0.81-1.05) and in the rate of small-for-gestational-age infants (12 studies; RR, 0.96; 95% CI, 0.87-1.07) among offspring of mothers treated with aspirin and those of mothers treated with a placebo. CONCLUSION: For women with moderate- and high-risk pregnancies, aspirin treatment seemed to have a small but significant effect on reducing the rate of preterm deliveries, but did not reduce the rate of perinatal death.

Abnormalities, Drug-Induced↗
PubMed2003

Folic acid food fortification is associated with a decline in neuroblastoma.

BACKGROUND: Neuroblastoma, an embryonic tumor, is the second most common pediatric tumor and is the most prevalent extracranial solid tumor in children. Results of previous studies have suggested that maternal vitamin intake may decrease the risk of several childhood cancers. In January 1997, Canada began fortifying flour with folic acid for the prevention of neural tube defects. The effect of folic acid fortification on the rate of neuroblastoma in offspring is not known. METHODS: We investigated the rates of neuroblastoma (<1 year), acute lymphoblastic leukemia, and hepatoblastoma registered by the Pediatric Oncology Group of Ontario, which captures 95% of all pediatric cancers in Ontario, before and after the introduction of folate fortification. RESULTS: An interventional time series analysis showed that the incidence of neuroblastoma declined from 1.57 cases per 10,000 births before to 0.62 case per 10,000 births after folic acid fortification (P <.0001). The crude incidence rate ratio (0.40; 95% confidence interval, 0.25-0.64) remained significant after adjustment for both age and disease stage at diagnosis (adjusted incidence rate ratio, 0.38; 95% confidence interval, 0.23-0.62). In contrast, there was no significant change in the rate of infant acute lymphoblastic leukemia (incidence rate ratio, 0.97; 95% confidence interval, 0.41-2.27) or hepatoblastoma (incidence rate ratio, 0.81; 95% confidence interval, 0.35-1.89). CONCLUSIONS: Folic acid fortification was associated with a 60% reduction in neuroblastoma but was not associated with any change in the rate of infant acute lymphoblastic leukemia or hepatoblastoma. Further investigation is needed into the role of metabolism in the formation and prevention of neuroblastoma and other embryonically determined cancers.

Canada↗
PubMed2003

Assessment of visual functions following prenatal exposure to organic solvents.

Prenatal exposure to organic solvents has been previously associated with increased risk of color vision deficits and reduced visual acuity in young children. These findings prompted us to evaluate visual functioning in solvent-exposed infants using more sensitive non-invasive visual evoked potential (VEP) techniques. VEP techniques are described in the context of an ongoing prospective longitudinal cohort study of infants exposed to organic solvents in utero. VEPs are recorded via three active electrodes fitted over the occipital cortex while infants view changing visual stimuli. The sweep VEP is used to assess contrast detection and visual acuity by presenting sinusoidal gratings that "sweep" across a range of contrasts and spatial frequencies. Transient VEPs are used to assess responses to equiluminant chromatic- and luminance-modulated sinusoidal gratings presented in pattern onset-offset format. A single case study is presented showing abnormal chromatic responses and reduced contrast sensitivity in a 2.5-year-old boy following prenatal exposure to perchloroethylene (PCE). These VEP techniques therefore appear promising for the clinical assessment of visual toxicity in pediatric populations.

Child, Preschool↗
PubMed2003

Diclectin therapy for nausea and vomiting of pregnancy: effects of optimal dosing.

OBJECTIVES: (1) To quantify rates of suboptimal use of pyridoxine hydrochloride-doxylamine (Diclectin); and (2) to study responses to optimal doses of Diclectin in women previously taking a suboptimal dose. METHODS: Women who called the Motherisk NVP helpline, and were taking only Diclectin (vitamin B6 10 mg and doxylamine 10 mg), were enrolled in the study and assessed for the severity of nausea and vomiting of pregnancy (NVP) with the Motherisk-PUQE (pregnancy-unique quantification of emesis and nausea) scoring system. Their Diclectin doses were subsequently increased according to body weight and individual symptoms. A follow-up phone call occurred within 1 to 3 weeks after the intervention, at which time the overall PUQE score was repeated, along with individual scoring of symptoms of nausea, vomiting, and retching. RESULTS: Sixty-eight women were enrolled and completed the study. Despite moderate to severe NVP, defined by the validated PUQE scoring system, most women (50/68) were receiving 2 tablets a day of Diclectin instead of the recommended dose of 4 tablets a day. Following a mean doubling of the dose to 4 tablets a day, there was a significant decrease in length of nausea (from 4 to 3 hours, P < 0.001), frequency of vomiting (from mean 1.6 to 1.3 a day, P = 0.02), and overall PUQE score (from mean 7.5 to 6.1, P < 0.001). CONCLUSION: Women suffering from NVP are often given subtherapeutic doses of Diclectin. Women should receive a dosage according to their body weight and severity of their symptoms.

Adult↗
PubMed2003

Healthy children as subjects in pharmaceutical research.

Recruitment of healthy children for drug research has emerged due in part to several new American laws and policies that have led to a surge in pharmaceutical research involving children-subjects. In this paper, I review the ethical and scientific issues and the arguments in favor and against this new practice.

Child↗
PubMed2003

Fetal safety of loratadine use in the first trimester of pregnancy: a multicenter study.

BACKGROUND: Women in their childbearing years often require drug therapy for allergic conditions. Loratadine, a newer nonsedating antihistamine, is often used because of its preferred side effect profile. To date no published data exist on the safety of loratadine use in pregnancy. OBJECTIVE: We sought to determine whether the use of loratadine in the first trimester of pregnancy was associated with an increased risk for major malformations. Secondary outcomes included rates of miscarriage, birth weights, and gestational age at delivery. METHODS: All women were prospectively enrolled from 4 participating centers. Detailed maternal medical history and drug exposures were collected at intake, whereas pregnancy complications and outcomes were collected at follow-up. A group of unexposed control subjects were recruited and followed up in a similar manner. RESULTS: This report includes follow-up on 161 loratadine exposed pregnancies and an equal number of unexposed control subjects. Maternal characteristics (age, pregnancy history, alcohol consumption, and smoking habits) were not different between the 2 groups. There were 5 malformations observed in the exposed group and 6 in the control group, which was not significantly different (P =.9) Similarly, the live birth rate, gestational age at delivery, and birth weights were not different between the 2 groups. CONCLUSION: These results suggest that loratadine use in pregnancy is not associated with a large risk for major malformations. Further studies are warranted to confirm these findings and to increase study power.

Abnormalities, Drug-Induced↗
PubMed2003

Hypotension and bradycardia in infants after the use of topical brimonidine and beta-blockers.

Brimonidine is a selective alpha-2 adrenergic agonist used to treat glaucoma. There have been several reports of central nervous system depression after its use in infants. We observed rapid-onset bradycardia and decreased blood pressure in addition to central nervous system depression in 2 infants who received concomitant topical brimonidine and beta-blockers.

Administration, Topical↗
PubMed2003

Digoxin-carvedilol interactions in children.

Digoxin is often coadministered with carvedilol in children with severe ventricular failure. In eight children (age 2 weeks to 8 years), the oral clearance of digoxin decreased by half with carvedilol, and two of them had digoxin toxicity. Carvedilol increases serum concentrations of digoxin in children, and its dose may need to be reduced to avoid toxicity.

Carbazoles↗
PubMed2003

Measuring a toddler's mouthful: toxicologic considerations.

The volume of a toddler's mouthful needs to be defined to estimate poisoning risk. We calculated a toddler's mouthful in 66 healthy children (1.5-4.5 years old) by measuring apple juice remaining in a cup after sipping. Mean volume was 9.3 mL (range, 3.5-29; 95% confidence interval, 8-11), twofold larger than commonly quoted values.

Child, Preschool↗
PubMed2003

Prospective comparative study of the safety and effectiveness of ginger for the treatment of nausea and vomiting in pregnancy.

OBJECTIVES: The primary objective of our study was to examine the safety and the secondary objective was to examine the effectiveness of ginger for nausea and vomiting of pregnancy (NVP). STUDY DESIGN: Pregnant women who called the Motherisk Program who were taking ginger during the first trimester of pregnancy were enrolled in the study. The women were compared with a group of women who were exposed to nonteratogenic drugs that were not antiemetic medications. The women were followed up to ascertain the outcome of the pregnancy and the health of their infants. They were also asked on a scale of 0 to 10 how effective the ginger was for their symptoms of NVP. RESULTS: We were able to ascertain the outcome of 187 pregnancies. There were 181 live births, 2 stillbirths, 3 spontaneous abortions, and 1 therapeutic abortion. The mean birth weight was 3542+/-543 g, the mean gestational age was 39+/-2 weeks, and there were three major malformations. There were no statistical differences in the outcomes between the ginger group and the comparison group with the exception of more infants weighing less than 2500 g in the comparison group (12 vs 3, P < or =.001). There were a total of 66 completed effectiveness scores with the mean score of 3.3+/-2.9 SD. CONCLUSION: These results suggest that ginger does not appear to increase the rates of major malformations above the baseline rate of 1% to 3% and that it has a mild effect in the treatment of NVP.

Birth Weight↗
PubMed2003

Utility of antiepileptic drug monitoring in the pediatric emergency department.

Convulsive disorders are common in the pediatric age group, and measurement of serum concentration of an antiepileptic drug (AED) is frequently ordered for epileptic patients in the emergency department (ED). The objective of this study was to develop a better understanding of the indications for, and consequences of, monitoring AED serum concentrations in the pediatric ED. Charts of 116 patients who visited the ED and were tested for blood levels of AED were retrospectively reviewed. Main outcome measures were number and percentage of levels outside the therapeutic range, discontinuation of an AED or introduction of a new one, dosage modifications, and admission to hospital. Two pediatricians and a pediatric neurologist aware only of patients' age, weight, diagnosis, history, clinical presentation, and drug details reviewed each case and on the basis of predetermined criteria decided whether measurement of AED was indicated. Mean age (+/- SD) of the study population was 7 +/- 5 years (range, 2 months-17 years). Forty-two patients (36%) were on monotherapy, and 74 (64%) were on polytherapy. Sixty-eight patients (59%) presented with increased seizure frequency, 7 (6%) with status epilepticus, and 13 (11%) with suspected AED toxicity. The remainder of the children presented with problems unrelated to epilepsy. No significant difference was found between patients with AED levels within the therapeutic range and those with levels outside it in the proportion of children needing dosage change, change in medication, or hospital admission (P = 0.5, 0.8, and 0.8, respectively). None of the patients presenting with status epilepticus and only 15% of those with increased seizure activity had subtherapeutic levels. Review of the cases suggested that measuring serum AED level was not indicated in 57 (49.1%) patients. In the pediatric ED, abnormal AED levels do not correlate with clinical management. Before ordering tests, physicians should consider whether their results would alter patient treatment.

Adolescent↗
PubMed2003

Population baseline of meconium fatty acid ethyl esters among infants of nondrinking women in Jerusalem and Toronto.

The detection of fatty acid ethyl esters (FAEE) in meconium may provide an objective estimate of prenatal alcohol exposure independent of maternal history. The authors report the results of the first population-based study conducted to investigate basal FAEE levels in the meconium of neonates not exposed to alcohol. Two hundred seven nondrinking women and their neonates were recruited from Toronto and Jerusalem. FAEE were extracted from meconium by solid-phase extraction and analyzed by GC/FID. Similar procedures were conducted in six neonates born to confirmed heavy drinkers. Low levels of meconium FAEE were detected from both cohorts (mean, 1.37 nmol/g vs. 2.08 nmol/g, Toronto vs. Jerusalem). Ethyl stearate, oleate, and linoleate were below the limit of detection in >80% of all samples, whereas ethyl laurate and palmitate were detected in >50% of the samples. Ethyl myristate was the FAEE most commonly detected (>80%). All six meconium samples with confirmed maternal drinking histories tested positive for FAEE at significantly higher levels (mean, 11.08 nmol/g). The use of 2 nmol total FAEE/g meconium as the positive cutoff, when lauric and myristic acid ethyl esters were excluded, yielded the greatest sensitivity (100%) and specificity (98.4%). The authors conclude that certain FAEE are present at measurable levels in the meconium of neonates not exposed to maternal drinking, and correction is needed to allow high specificity.

Adult↗