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Biomedical subjects

Gideon Koren

Publications and source records attributed to Gideon Koren.

At least 19 recordsLinked to original sources
PubMed2007

Validation of the oral mucositis assessment scale in pediatric cancer.

BACKGROUND: Our objective was to examine the construct validity of the Oral Mucositis Assessment Scale (OMAS) in children receiving doxorubicin chemotherapy. METHODS: Children between 6 and 18 years of age with cancer receiving doxorubicin-containing chemotherapy were included. OMAS was measured on days 7, 10, 14, and 17 after chemotherapy. Other measures of mucositis obtained concurrent with OMAS were the World Health Organization (WHO) mucositis scale and pain visual analogue scale (VAS). We also recorded analgesia administration. RESULTS: Sixteen children were studied for 45 post-chemotherapy cycles and 156 OMAS assessments were performed. OMAS was moderately correlated with WHO scores (r = 0.56; P = 0.0006) whereas correlation with the pain VAS was fair (r = 0.37; P = 0.002). OMAS also had fair correlation with the number of doses of topical analgesia (r = 0.43; P = 0.001) and with the cumulative dose of opioid analgesia (r = 0.38; P = 0.003). CONCLUSIONS: The OMAS is valid for use in mucositis clinical trials for children at least 6 years of age.

Administration, Oral↗
PubMed2007

Pharmaceutical agents and pregnancy in urology practice.

Urologic medical conditions are not frequently encountered during pregnancy. Still, urologists often are asked to treat pregnant patients for conditions that require prescriptions. In the generally healthy population of pregnant women, the use of pharmaceutical agents is usually reserved for women who have either infections or necessary surgical procedures. This article addresses the implications for pregnancy of common urologic conditions in generally healthy pregnant women, namely simple urinary tract infections that demand nitrofurantoin and complex urinary tract infections that necessitate fluoroquinolones treatment. It also examines the implications of nonobstetric surgical intervention.

Female↗
PubMed2006

Breast-feeding during maternal use of azathioprine.

OBJECTIVE: To report the clinical outcome of infants whose mothers were taking azathioprine while nursing and to quantify the transfer of 6-mercaptopurine (6-MP), its active metabolite, into breast milk. CASE SUMMARY: We report on a series of 4 patients treated with azathioprine while lactating. Breast milk samples were analyzed for 6-MP in 2 of the mothers. Several milk samples per patient were analyzed; levels of 6-MP were undetectable by high performance liquid chromatography (limit of detection 5 ng/mL). Therefore, the absolute relative infant dose would have been less than 0.09% of the maternal weight-adjusted dose. No adverse effects were encountered in any of the 4 infants. DISCUSSION: A large number of women of reproductive age are treated with azathioprine for a range of chronic conditions that require immunosuppression, such as systemic lupus erythematosus or solid organ transplants. Similar to other antimetabolites, the drug has generally been contraindicated for use during breast-feeding because of the theoretical concern for toxicity in the nursing infant. The available literature in this area is sparse and dated. The data presented here confirm published reports of minimal 6-MP excretion into milk, suggesting that significant systemic adverse effects in the infant are unlikely. CONCLUSIONS: Maternal azathioprine use during lactation does not appear to pose a significant immediate clinical risk to the suckling infant. Continued monitoring and long-term assessment of these infants are warranted.

Adult↗
PubMed2006

Safety and efficacy of black cohosh (Cimicifuga racemosa) during pregnancy and lactation.

BACKGROUND: There is a lack of basic knowledge on the part of both clinicians and patients as to the indications for use and safety of herbal medicines in pregnancy and lactation. This is one article in a series that systematically reviews the evidence for commonly used herbs during pregnancy and lactation. OBJECTIVES: To systematically review the literature for evidence on the use, safety, and pharmacology of black cohosh focusing on issues pertaining to pregnancy and lactation. METHODS: We searched 7 electronic databases and compiled data according to the grade of evidence found. RESULTS: Black cohosh, alone or in combination with other medicinal herbs as "mother's cordial", has a long traditional use and is frequently used by midwives as a uterine stimulant and labour-inducing aid. Low-level evidence based on theory and expert opinion shows the following concerns with respect to black cohosh use during pregnancy: 1) labour-inducing effects, 2) hormonal effects, 3) emmenagogue properties and, 4) anovulatory effects. During lactation, there is low-level evidence from theoretical and expert opinion of black cohosh having hormonal properties. CONCLUSIONS: Black cohosh should be used with caution during pregnancy, particularly during the first trimester where its purported labour-inducing effects could be of concern, and during lactation. Black cohosh should undergo rigorous high quality human studies to determine its safety in pregnancy and lactation.

Cimicifuga↗
PubMed2006

Safety and efficacy of echinacea (Echinacea angustafolia, e. purpurea and e. pallida) during pregnancy and lactation.

BACKGROUND: There is a lack of basic knowledge on the part of both clinicians and patients as to the indications for use and safety of herbal medicines used in pregnancy and lactation. This is one article in a series that systematically reviews the evidence for commonly used herbs during pregnancy and lactation. OBJECTIVES: To systematically review the literature for evidence on the use, safety, and pharmacology of echinacea focusing on issues pertaining to pregnancy and lactation. METHODS: We searched 7 electronic databases and compiled data according to the grade of evidence found. RESULTS: There is good scientific evidence from a prospective cohort study that oral consumption of echinacea during the first trimester does not increase the risk for major malformations. Low-level evidence based on expert opinion shows that oral consumption of echinacea in recommended doses is safe for use during pregnancy and lactation. CONCLUSIONS: Echinacea is non-teratogenic when used during pregnancy. Caution with using Echinacea during lactation until further high quality human studies can determine its safety.

Administration, Oral↗
PubMed2006

Safety and efficacy of St. John's wort (hypericum) during pregnancy and lactation.

BACKGROUND: There is a lack of basic knowledge on the part of both clinicians and patients as to the indications for use and safety of herbal medicines in pregnancy and lactation. This is one article in a series that systematically reviews the evidence for commonly used herbs during pregnancy and lactation. OBJECTIVES: To systematically review the literature for evidence on the use, safety, and pharmacology of St. John's wort focusing on issues pertaining to pregnancy and lactation. METHODS: We searched 7 electronic databases and compiled data according to the grade of evidence found. RESULTS: There is very weak scientific evidence based on a case report that St Johns wort is of minimal risk when taken during pregnancy. There is in vitro evidence from animal studies that St John's wort during pregnancy does not affect cognitive development nor cause long-term behavioral defects, but may lower offspring birth weight. There is weak scientific evidence that St. John's wort use during lactation does not affect maternal milk production nor affect infant weight, but, in a few cases, may cause colic, drowsiness or lethargy. There is weak scientific evidence that St John's wort induces CYP450 enzymes, which may lower serum medication levels below therapeutic range; this may be of concern when administering medications during pregnancy and lactation. CONCLUSIONS: Caution is warranted with the use of St John's wort during pregnancy until further high quality human research is conducted to determine its safety. St John's wort use during lactation appears to be of minimal risk, but may cause side effects. Caution is warranted when using medications along with St John's wort.

Animals↗
PubMed2006

Safety and efficacy of ginkgo (Ginkgo biloba) during pregnancy and lactation.

BACKGROUND: There is a lack of basic knowledge on the part of both clinicians and patients as to the indications for use and safety of herbal medicines used in pregnancy and lactation. This is one article in a series that systematically reviews the evidence for commonly used herbs during pregnancy and lactation. OBJECTIVES: To systematically review the literature for evidence on the use, safety, and pharmacology of ginkgo focusing on issues pertaining to pregnancy and lactation. METHODS: We searched 7 electronic databases and compiled data according to the grade of evidence found. RESULTS: There is some very weak scientific evidence from animal and in vitro studies that ginkgo leaf has antiplatelet activity, which may be of concern during labour as ginkgo use could prolong bleeding time. Low-level evidence based on expert opinion shows that ginkgo leaf may be an emmenagogue and have hormonal properties. The safety of ginkgo leaf during lactation is unknown. Patients and clinicians should be aware of past reports of ginkgo products being adulterated with colchicine. CONCLUSIONS: Ginkgo should be used with caution during pregnancy, particularly around labour where its anti-platelet properties could prolong bleeding time. During lactation the safety of ginkgo leaf is unknown and should be avoided until high quality human studies are conducted to prove its safety.

Animals↗
PubMed2006

The effect of a short tutorial on the incidence of prescribing errors in pediatric emergency care.

BACKGROUND: In the paediatric emergency department (ED) trainees are more likely to commit prescribing errors. OBJECTIVE: To determine whether a short educational intervention reduces the incidence of prescribing errors among trainees in a pediatric ED. METHODS: A prospective cohort study at the ED of a tertiary paediatric hospital. All fellows and residents arriving at the ED at the beginning of the academic year were invited to participate in a 30-minute tutorial focusing on appropriate methods for prescribing medications, followed by a written test. Eighteen days were selected randomly during July 2001. All the charts from these days were reviewed for medication errors. Two reviewers, blinded to whether or not a particular physician attended the tutorial, independently decided whether or not an error had occurred. The main outcome measure was the number of prescribing errors. RESULTS: Twenty-two trainees worked in the ED during July 2001. Of these, 13 trainees attended the tutorial. Eight hundred and ninety nine orders given by trainees were evaluated. We identified 66 (12.4%) errors in 533 orders given by those who attended tutorial, and 46 (12.7%) errors in 363 orders given by those who did not attend tutorial. The adjusted odds of a medication error was not significantly different between those who did not attend the tutorial and those who did (OR: 1.07 95% CI: 0.66-1.70). CONCLUSIONS: A short tutorial, followed by a written test, administered to trainees before entering their rotation in the paediatric ED, did not appear to reduce prescribing errors.

Clinical Competence↗
PubMed2006

Health-related quality of life of Canadian children and youth prenatally exposed to alcohol.

BACKGROUND: In Canada, the incidence of Fetal Alcohol Spectrum Disorder (FASD) has been estimated to be 1 in 100 live births. Caused by prenatal exposure to alcohol, FASD is the leading cause of neuro-developmental disabilities among Canadian children, and youth. OBJECTIVE: To measure the health-related quality of life (HRQL) of Canadian children and youth diagnosed with FASD. METHODS: A prospective cross-sectional study design was used. One-hundred and twenty-six (126) children and youth diagnosed with FASD, aged 8 to 21 years, living in urban and rural communities throughout Canada participated in the study. Participants completed the Health Utilities Index Mark 3 (HUI3). HUI3 measures eight health attributes: vision, hearing, speech, ambulation, dexterity, emotion, cognition, and pain. Utilities were used to measure a single cardinal value between 0 and 1.0 (0 = all-worst health state; 1 = perfect health) to reflect the global HRQL for that child. Mean HRQL scores and range of scores of children and youth with FASD were calculated. A one-sample t-test was used to compare mean HRQL scores of children and youth with FASD to those from the Canadian population. RESULTS: Mean HRQL score of children and youth with FASD was 0.47 (95% CI: 0.42 to 0.52) as compared to a mean score of 0.93 (95% CI: 0.92 to 0.94) in those from the general Canadian population (p < 0.001). Children demonstrated moderate to severe dysfunction on the single-attributes of cognition and emotion. CONCLUSION: Children and youth with FASD have significantly lower HRQL than children and youth from the general Canadian population. This finding has significant implications for practice, policy development, and research.

Adolescent↗
PubMed2006

Comparison of verbal claims for natural health products made by health food stores staff versus pharmacists in Ontario, Canada.

BACKGROUND: This study tested the hypothesis that while there are no written medical claims existing for many NHP, such claims are made verbally, giving a false impression that these are proven medical products. OBJECTIVE: To compare the number and type of verbal claims for NHP made by pharmacists to those made by health food stores personnel. METHODS: Randomly selected Canadian pharmacies selling NHP and health food stores were visited and the staff was asked to recommend natural health products for the treatment of hypertension. RESULTS: All health food stores (n=20) but only 4 out of 38 pharmacies (p< 0.001) recommended NHP for the treatment of hypertension. A majority of health food store staff (70%) stated that NHP are superior or equal to medicinal drugs in treating hypertension based on efficacy. CONCLUSION: Unlike pharmacy practice, verbal claims are common practice in health food stores, despite the lack of either written claims and/or proof of efficacy for most of them. These may be a very effective approach given that 30-40% of North American adults are functionally illiterate. These verbal claims are often inappropriate and not evidence-based.

Adolescent↗
PubMed2006

Novel approaches to the diagnosis of fetal alcohol spectrum disorder.

The diagnosis of fetal alcohol spectrum disorder is a difficult task, especially in cases where clear, physical markers of in utero alcohol exposure are not apparent. Reviewed in the following paper are some older tools for screening alcohol use in pregnancy and present novel approaches to the diagnosis of FASD, including ethanol biomarker development to behavioural phenotyping. Improving current FASD diagnostic methodology through more novel approaches may provide the possibility of earlier and wider diagnosis, allowing intervention and treatment at stages where the advanced effects of alcohol can still be mitigated.

Alcohols↗
PubMed2006

Pregnancy outcome after first-trimester exposure to metformin: a meta-analysis.

OBJECTIVE: To conduct a systematic review and meta-analysis of pregnancy outcome after metformin use for polycystic ovary syndrome (PCOS), because the efficacy of metformin has been demonstrated in the treatment of infertility caused by PCOS, whereas the fetal safety of metformin has received very little attention, and the few studies addressing this issue are limited by small sample sizes. DESIGN: Meta-analytic review. SETTING: All pertinent studies in MEDLINE and EMBASE from 1966 to September 2004. PATIENT(S): Women with PCOS or diabetes. INTERVENTION(S): Exposure to metformin in the first trimester of pregnancy. MAIN OUTCOME MEASURE(S): Major malformations. RESULT(S): Eight studies were included in the meta-analysis, with an odds ratio of 0.50 (95% confidence interval, 0.15, 1.60). After adjustment for publication bias, metformin treatment in the first trimester was associated with a statistically significant 57% protective effect. After pooling the studies, the malformation rate in the disease-matched control group was approximately 7.2%, statistically significantly higher than the rate found in the metformin group (1.7%). CONCLUSION(S): On the basis of the limited data available today, there is no evidence of an increased risk for major malformations when metformin is taken during the first trimester of pregnancy. Large studies are needed to corroborate these preliminary results.

Abnormalities, Drug-Induced↗
PubMed2006

Fatty acid ethyl esters (FAEE); comparative accumulation in human and guinea pig hair as a biomarker for prenatal alcohol exposure.

AIMS: To compare the incorporation rate (ICR) of fatty acid ethyl esters (FAEE) in hair between guinea pigs and humans, and to assess the relationship between ethanol exposure and FAEE concentrations in hair. METHODS: Published data from pregnant guinea pigs, including maximum blood ethanol concentration (BEC), dosage regimen, and total hair FAEE concentration, were compared with published data from alcoholic patients, where dose of ethanol consumed and total hair FAEE concentration were reported. Mean values of ethanol Vmax for pregnant guinea pigs and humans were obtained from published data (26.2 and 24 mg/dl/h, respectively). RESULTS: Total and individual FAEE ICRs, defined as the ratio of hair FAEE to the area under the BEC-time curve (total systemic ethanol exposure), were found to be on average an order of magnitude lower in the guinea pig than in the human. The profiles of ester incorporation also differed slightly between species, with ethyl stearate being highly incorporated in guinea pig hair and less so in human hair. The results may reflect in the human greater FAEE production, greater FAEE deposition in hair, slower FAEE catabolism, differential sebum production and composition, or a combination thereof. Also, ethyl oleate was found to correlate with total systemic ethanol exposure for both guinea pigs and humans, correlation coefficients equalling 0.67 (P < 0.05) and 0.49 (P < 0.05), respectively. No other ethyl esters, nor total FAEE, were found to correlate with systemic ethanol exposure. CONCLUSION: When extrapolating FAEE concentrations in hair from guinea pigs to humans, an order of magnitude difference should be considered, with humans incorporating more FAEE per unit of ethanol exposure. Also, the results suggest caution should be taken when interpreting values of single esters because of their differential incorporation among species. Lastly, our findings suggest ethyl oleate may be of keen interest in FAEE hair analysis, particularly across species.

Adult↗
PubMed2006

Pregnancy outcome following gestational exposure to azithromycin.

BACKGROUND: Azithromycin is an azalide antibiotic with an extensive range of indications and has become a common treatment option due to its convenient dosing regimen and therapeutic advantages. Human studies addressing gestational use of azithromycin have primarily focused on antibiotic efficacy rather than fetal safety. Our primary objective was to evaluate the possibility of teratogenic risk following gestational exposure to azithromycin. METHODS: There were 3 groups of pregnant women enrolled in our study: 1) women who took azithromycin, 2) women exposed to non-teratogenic antibiotics for similar indications, and 3) women exposed to non-teratogenic agents. They were matched for gestational age at time of call, maternal age, cigarette and alcohol consumption. Rates of major malformations and other endpoints of interest were compared among the three groups. RESULTS: Pregnancy outcome of 123 women in each group was ascertained. There were no statistically significant differences among the three groups in the rates of major malformations; 3.4% (exposed) versus 2.3% (disease matched) and 3.4% (non teratogen) or any other endpoints that were examined. In the azithromycin group, 88 (71.6%) women took the drug during the first trimester CONCLUSION: Results suggest that gestational exposure to azithromycin is not associated with an increase in the rate of major malformations above the baseline of 1-3%. Our data adds to previous research showing that macrolide antibiotics, as a group, are generally safe in pregnancy and provides an evidence-based option for health professionals caring for populations with chlamydia.

Journal Article↗
PubMed2006

Occurrence and impact of unanticipated variation in intravenous methotrexate dosing.

BACKGROUND: Studies using direct measurement suggest that the doses of up to 65% of drug infusions are outside industry standards. These preparation-associated errors occur despite routine safety procedures. As of April 5, 2006, the clinical impact of these errors had not been evaluated. OBJECTIVE: To measure the occurrence and associated clinical outcomes of variations in intravenous methotrexate dosing. METHODS: A prospective observational study was performed on 47 methotrexate infusions of 800 mg/m2 that were administered to 19 children with acute lymphoblastic leukemia. Serum methotrexate concentrations were measured at the end of the infusions, which were administered over 24 hours. The total methotrexate dose was determined by direct measurement of the concentration and the volume of each infusion. RESULTS: Dosing errors greater than or equal to 10% occurred in 11 (23%) infusions and ranged from -61% to 55% of the ideal dose. Repeated measures regression analysis found the measured total methotrexate dose was not significantly associated with the serum methotrexate concentration (p = 0.58) or with clinical toxicities. The methotrexate dose administered over the last hours of infusion (p = 0.006) and the serum creatinine level at diagnosis (p = 0.05) were the most significant predictors of the methotrexate concentration. High methotrexate concentrations were significantly associated with increased hepatic aminotransferase levels; however, the degree of elevation was of limited clinical relevance. CONCLUSIONS: While unexpected errors in drug dosing are more common than is suggested by other methods, the clinical impact observed in this model of methotrexate infusion was not demonstrably greater than medication errors described by other methods. Subsequent studies in this model of dosing error will require larger sample sizes, and other drugs should be evaluated.

Antimetabolites, Antineoplastic↗
PubMed2006

Nonsteroidal antiinflammatory drugs during third trimester and the risk of premature closure of the ductus arteriosus: a meta-analysis.

BACKGROUND: Nonsteroidal antiinflammatory drugs (NSAIDs) are increasingly being used during pregnancy to treat a variety of conditions. An evaluation of the risk of premature closure of the ductus arteriosus is useful in determining the safety of NSAIDs at different stages of pregnancy. OBJECTIVE: To determine whether NSAID use during the third trimester of pregnancy is associated with an increased risk of premature constriction of the ductus arteriosus. METHODS: A systematic review was conducted of MEDLINE (1966-2004), Embase (1980-2004), and the Cochrane Database of Systematic Reviews (1991-2004). Summary estimates of the odds ratios, comparing ductal outcomes in exposed and unexposed fetuses, and their 95% confidence intervals were calculated assuming a random effects model. RESULTS: Based on 217 patients exposed to indomethacin and 221 to placebo, the risk of ductal closure was 15-fold higher in the group of women exposed to NSAIDs compared with those receiving either placebo or other NSAIDs (8 studies; OR = 15.04, 95% CI 3.29 to 68.68). There was no significant increased risk of ductal closure in the infants of women treated with indomethacin compared with those receiving other drugs (4 studies; OR = 2.12, 95% CI 0.48 to 9.25). Similar results were found when calculating rate differences. CONCLUSIONS: Short-term use of NSAIDs in late pregnancy is associated with a significant increase in the risk of premature ductal closure.

Abnormalities, Drug-Induced↗
PubMed2006

A randomized cross over trial of tolerability and compliance of a micronutrient supplement with low iron separated from calcium vs high iron combined with calcium in pregnant women [ISRCTN56071145].

BACKGROUND: Prenatal micronutrient combinations with high iron content are associated with high rates of gastrointestinal symptoms. This coupled with nausea and vomiting of pregnancy results in women often discontinuing their multivitamins. A new prescription supplement (PregVit) that separates iron from calcium in two tablets--morning and evening, has lower elemental iron content (35 mg), but results in similar extent of iron absorption when compared to another supplement containing (60 mg) of elemental iron (Materna). The objectives of this study were to compare tolerability and compliance with PregVit vs. a supplement with high iron content (Materna), in pregnant women. METHODS: Randomized, crossover open labeled study in 135 pregnant women attending outpatient clinics in Ontario and Quebec. RESULTS: Use of PregVit was associated with a 30% reduction in constipation rate as compared to Materna. Both products demonstrated similar compliance rates. Compliance of Materna was negatively associated with the severity of nausea and vomiting of pregnancy. No such correlation was found for PregVvit. CONCLUSION: PregVit, a supplement with lower iron content (35 mg), has significantly decreased constipation rates as compared to 60 mg iron--Materna and has similar compliance rates. High iron content in multivitamin supplements is associated with adverse effects in pregnancy.

Journal Article↗