Changes in renal function over time in outpatients with eGFR ≥ 30 mL/min/1.73 m2: implication for timing of renal function testing before contrast-enhanced CT imaging

PURPOSE

To evaluate the associations between comorbidities and kidney function decline at 6-month and 1-year follow-up in outpatients with initial estimated glomerular filtration rate (eGFR) ≥ 30 mL/min/1.73 m2.

MATERIALS AND METHODS

Outpatients aged 18 and older with confirmed diagnosis, who had eGFR ≥ 30 mL/min/1.73 m2 measured between April 2017 and March 2019, were included in this retrospective observational study. Of them, 30,595 included outpatients had 6-month eGFR test and 27,698 included outpatients had 1-year eGFR test. The outpatients were further divided into two groups based on initial eGFR: between 30 and 59 and ≥ 60 mL/min/1.73 m2. Impaired renal function was defined as eGFR declined to below 30 mL/min/1.73 m2. The comorbidities with P values less than 0.1 identified in univariable logistic regression models were entered into the multivariable analysis with backward selection, thereby identifying comorbidities that increased the risk of eGFR decline at 6-month and 1-year follow-up.

RESULTS

Outpatients with initial eGFR between 30 and 59 mL/min/1.73 m2 were 175.94 times more likely to have eGFR decline at 6 months, and were 94.10 times more likely to have eGFR decline at 1 year, compared with their corresponding initial eGFR ≥ 60 counterparts. Multivariable logistic regression analyses disclosed that chronic kidney disease, hypertension, and heart failure were independent risk factors for eGFR decline in outpatients with initial eGFR between 30 and 59 mL/min/1.73 m2.

CONCLUSIONS

Outpatients with initial eGFR ≥ 60 mL/min/1.73 m2 might not need routine eGFR test prior to contrast-enhanced CT scan for 1 year. In addition, chronic kidney disease, hypertension, and heart failure increased the risk of declined renal function, particularly, in outpatients with initial eGFR between 30 and 59 mL/min/1.73 m2.

Strategies to Address Current Challenges in Real-World Evidence Generation in Japan

The generation of real-world evidence (RWE), which describes patient characteristics or treatment patterns using real-world data (RWD), is rapidly growing more popular as a tool for decision-making in Japan. The aim of this review was to summarize challenges to RWE generation in Japan related to pharmacoepidemiology, and to propose strategies to address some of these challenges. We first focused on data-related issues, including the lack of transparency of RWD sources, linkage across different care settings, definitions of clinical outcomes, and the overall assessment framework of RWD when used for research purposes. Next the study reviewed methodology-related challenges. As lack of design transparency impairs study reproducibility, transparent reporting of study design is critical for stakeholders. For this review, we considered different sources of biases and time-varying confounding, along with potential study design and methodological solutions. Additionally, the implementation of robust assessment of definition uncertainty, misclassification, and unmeasured confounders would enhance RWE credibility in light of RWD source-related limitations, and is being strongly considered by task forces in Japan. Overall, the development of guidance for best practices on data source selection, design transparency, and analytical methods to address different sources of biases and robustness in the process of RWE generation will enhance credibility for stakeholders and local decision-makers.

Perioperative Analgesics and Anesthesia as Risk Factors for Postoperative Chronic Opioid Use in Patients Undergoing Total Knee Arthroplasty: A Retrospective Cohort Study Using Japanese Hospital Claims Data

BACKGROUND

Patients with chronic postsurgical pain are commonly prescribed opioids chronically because of refractory pain although chronic opioid use can cause various severe problems.

OBJECTIVE

We aimed to investigate postoperative chronic opioid use and its association with perioperative pain management in patients who underwent a total knee arthroplasty in a Japanese real-world clinical setting.

METHODS

We conducted a retrospective cohort study using an administrative claims database. We used a multivariate logistic regression analysis to examine the association between perioperative analgesic and anesthesia prescriptions and postoperative chronic opioid use. We calculated all-cause medication and medical costs for each patient.

RESULTS

Of the 23,537,431 patient records, 14,325 patients met the criteria and were included in the analyses. There were 5.4% of patients with postoperative chronic opioid use. Perioperative prescriptions of weak opioids, strong and weak opioids, and the α₂δ ligand were significantly associated with postoperative chronic opioid use (adjusted odds ratio [95% confidence interval], 7.22 [3.89, 13.41], 7.97 [5.07, 12.50], and 1.45 [1.13, 1.88], respectively). Perioperative combined prescriptions of general and local anesthesia were also significantly associated with postoperative chronic opioid use (3.37 [2.23, 5.08]). These medications and local anesthesia were more commonly prescribed on the day following surgery, after routinely used medications and general anesthesia were prescribed. The median total direct costs were approximately 1.3-fold higher among patients with postoperative chronic opioid use than those without postoperative chronic opioid use.

CONCLUSIONS

Patients who require supplementary prescription of analgesics for acute postsurgical pain are at high risk of postoperative chronic opioid use and these prescriptions should be given careful consideration to mitigate the patient burden.

Validation of algorithms to identify colorectal cancer patients from administrative claims data of a Japanese hospital

BACKGROUND

Administrative claims data are a valuable source for clinical studies; however, the use of validated algorithms to identify patients is essential to minimize bias. We evaluated the validity of diagnostic coding algorithms for identifying patients with colorectal cancer from a hospital's administrative claims data.

METHODS

This validation study used administrative claims data from a Japanese university hospital between April 2017 and March 2019. We developed diagnostic coding algorithms, basically based on the International Classification of Disease (ICD) 10th codes of C18-20 and Japanese disease codes, to identify patients with colorectal cancer. For random samples of patients identified using our algorithms, case ascertainment was performed using chart review as the gold standard. The positive predictive value (PPV) was calculated to evaluate the accuracy of the algorithms.

RESULTS

Of 249 random samples of patients identified as having colorectal cancer by our coding algorithms, 215 were confirmed cases, yielding a PPV of 86.3% (95% confidence interval [CI], 81.5-90.1%). When the diagnostic codes were restricted to site-specific (right colon, left colon, transverse colon, or rectum) cancer codes, 94 of the 100 random samples were true cases of colorectal cancer. Consequently, the PPV increased to 94.0% (95% CI, 87.2-97.4%).

CONCLUSION

Our diagnostic coding algorithms based on ICD-10 codes and Japanese disease codes were highly accurate in detecting patients with colorectal cancer from this hospital's claims data. The exclusive use of site-specific cancer codes further improved the PPV from 86.3 to 94.0%, suggesting their desirability in identifying these patients more precisely.

Impact of "time zero" of Follow-Up Settings in a Comparative Effectiveness Study Using Real-World Data with a Non-user Comparator: Comparison of Six Different Settings

BACKGROUND

Time-related bias can lead to misleading conclusions. Properly setting the "time zero" of follow-up is crucial for avoiding these biases. However, the time-zero setting is challenging when comparing users and non-users of a study drug because the latter do not have a time point for starting treatment.

OBJECTIVE

This methodological study aimed to illustrate the impact of different time-zero settings on effect estimates in a comparative effectiveness study using real-world data with a non-user comparator.

METHODS

Data for type 2 diabetes patients were extracted from an administrative claims database, and the onset of diabetic retinopathy (study outcome) was compared between users (treatment group) and non-users (non-use group) of lipid-lowering agents. We applied six time-zero settings to the same dataset. The adjusted hazard ratio (HR) for the outcome was estimated using a Cox regression model in each time-zero setting, and the obtained results were compared among the settings.

RESULTS

Of the six settings, three (study entry date [SED] vs SED [naïve approach], treatment initiation [TI] vs SED, TI vs Matched [random order]) showed that the treatment had a reduced risk of the outcome (HR [95% CI]: 0.65 [0.61-0.69], 0.92 [0.86-0.97], and 0.76 [0.71-0.82], respectively), one (TI vs Random) had an increased risk (HR [95% CI]: 1.52 [1.40-1.64]) , and two (SED vs SED [cloning method], and TI vs Matched [systematic order]) had neither increased nor decreased risk (HR [95% CI]: 0.95 [0.93-1.13], and 0.99 [0.93-1.07], respectively).

CONCLUSIONS

This study demonstrates that different time-zero settings can lead to different conclusions, even if the same dataset is analyzed for the same research question, probably because improper settings can introduce bias. To minimize such biases, researchers should carefully define time zero, particularly when designing a non-user comparator study using real-world data.

Context and Considerations for Use of Two Japanese Real-World Databases in Japan: Medical Data Vision and Japanese Medical Data Center

In Japan, an increasing interest in real-world evidence for hypothesis generation and decision-making has emerged in order to overcome limitations and restrictions of clinical trials. We sought to characterize the context and concrete considerations of when to use Medical Data Vision (MDV) and JMDC databases, the main Japanese real-world data (RWD) sources accessible by pharmaceutical companies. Use cases for these databases, and related issues and considerations, were identified and summarized based on a literature search and experience-based knowledge. Studies conducted using MDV or JMDC were mostly descriptive in nature, or explored potential risk factors by evaluating associations with a target outcome. Considerations such as variable ascertainment at different time points, including issues relating to treatment identification and missing data, were highlighted for these two databases. Although several issues were commonly shared (e.g., only month of event occurrence reported), some database-specific issues were also identified and need to be accounted for. In conclusion, MDV and JMDC present limitations that are relatively typical of RWD sources, though some of them are unique to Japan, such as the identification of event occurrence and the inability to track patients visiting different healthcare settings. Addressing study design and careful result interpretation with respect to the specificities and uniqueness of the Japanese healthcare system is of particular importance. This aspect is especially relevant with respect to the growing global interest of conducting RWD studies in Japan.

Lyotropic liquid crystal-based transcutaneous peptide delivery system: Evaluation of skin permeability and potential for transcutaneous vaccination

Transcutaneous drug delivery is a promising method in terms of drug repositioning and reformulation because of its non-invasive and easy-to-use features. To overcome the skin barrier, which is the biggest challenge in transcutaneous drug delivery, a number of techniques, such as microemulsion, solid-in-oil dispersions and liposomes, have been studied extensively. However, the low viscosity of these formulations limits drug retention on the skin and reduces patient acceptability. Although viscosity can be increased by adding a thickening reagent, such an addition often alters formulation nanostructures and drug solubility, and importantly, decreases skin permeability. In this study, a gel-like lyotropic liquid crystal (LLC) was used as a tool to enhance skin permeability. In particular, we prepared 1-monolinolein (ML)-based LLCs with different water contents. All LLCs significantly enhanced skin permeation of a peptide drug, an epitope peptide of melanoma, despite their high viscoelasticity. Fourier transform infra-red spectroscopic analysis of the skin surface treated with the LLCs revealed that the gyroid geometry more strongly interacted with the lamellar structure inside the stratum corneum (SC) than the diamond geometry. Finally, as the result of the in vivo tumor challenge experiment using B16F10 melanoma-bearing mice, the LLC with the gyroid geometry showed stronger vaccine effect against tumor than a subcutaneous injection. Collectively, ML-based LLCs, especially with the gyroid geometry, are a promising strategy to deliver biomacromolecules into skin. STATEMENT OF SIGNIFICANCE: Transcutaneous drug delivery is a promising method for drug repositioning and reformulation because of its non-invasive and easy-to-use features. To overcome the skin barrier, which is the biggest challenge in transcutaneous drug delivery, we used a gel-like lyotropic liquid crystal (LLC) as a novel tool to enhance skin permeability. In this paper, we demonstrated that an LLC with a specific liquid crystalline structure has the highest skin permeation enhancement effect for a peptide antigen as a model drug. Moreover, the peptide antigen-loaded LLC showed a vaccine effect that was comparable to a subcutaneous injection in vivo. This study provides a basis for designing a transcutaneous delivery system of peptide drugs with LLC.

460Social inequalities in second-hand smoking among Japanese adults: A repeated cross-sectional study

Background

We aimed to examine the association between educational history and second-hand smoke (SHS) exposure in Japanese adults.

Methods

We conducted a repeated cross-sectional study using data from the 2007-2011 baseline and the 2013-2016 follow-up survey in a Japanese suburban area. Overall, 5,562 male and 5,381 female non-smokers participated in the study, which evaluated the SHS exposure and educational history of the participants through self-reported questionnaires. We performed a multilevel ordered logistic regression analysis with survey year as the first level and the individual as the second level, SHS exposure as the dependent variable, educational history as the explanatory variable, and age, smoking history, marital status as covariates, stratified by gender and working status.

Results

The prevalence of SHS exposure was 45.4% in males and 41.9% in females in the 2007-2011 survey, and 31.6% in males and 28.7% in females in the 2013-2016 survey. Multilevel analysis indicated that less educational history was associated with higher SHS exposure in both genders (among males, the odds ratio compared with ≥13 years was 1.75 for 10-12 years and 1.64 for ≤9 years; among females, it was 1.79 for 10-12 years and 2.43 for ≤9 years). Stratified analysis by working status showed that for females, education-based inequalities in SHS exposure more strongly impacted for workers than non-workers (p for interaction <0.001).

Conclusions

Education-based inequalities in SHS exposure exist in Japan and might be severe among female workers.

Key messages

Measures against SHS in Japan should be promoted to reduce social and gender inequalities.

The Impact of Job Conditions on Health-Related Quality of Life among Working Japanese Older Adults: A Five-Year Longitudinal Study Using J-MICC Okazaki Study Data

OBJECTIVES

The number of older adults who continue working after retirement is increasing in Japan. Little is known about how job conditions affect older adults' health. We examined the association between job conditions and health-related quality of life (HRQOL) during a five-year follow-up study.

METHODS

This study included participants aged 65 years or older from the Japan Multi-Institutional Collaborative Cohort Study in the Okazaki area recruited at baseline between 2007 and 2011 and followed up five years later. Participants completed a self-reported questionnaire on the physical and mental health aspects of HRQOL (SF-8™), employment status, and job conditions (job satisfaction, skill use, and job suitability).

RESULTS

Data of 1,146 men and 522 women were analyzed (mean age: 69.1 and 68.6 years, respectively). Generalized mixed linear regression analysis revealed that, compared to the not-working group, skill use was positively associated with mental health aspects among men (skill use × time: β = 0.16, SE = 0.08, p < 0.05), while poor job satisfaction and job suitability were negatively associated with mental health aspects among women (job satisfaction, not satisfied × time: β = -0.93, SE = 0.47, p < 0.05; job suitability, not suitable × time: β = -1.06, SE = 0.50, p < 0.05).

CONCLUSIONS

Regarding job conditions among older adults, skill use in men was marginally associated with mental health, and poor job satisfaction and suitability in women were negatively associated with mental health. Considering the job conditions of older workers is necessary to protect their mental health.

Association Between Second-hand Smoke Exposure and Depressive Symptoms Among Japanese Adults: A Cross-sectional Study

Background

Second-hand smoke exposure has been associated with poor mental health. However, among Japanese adults, little is known about the association between second-hand smoking and depressive symptoms. We examined this association in a cross-sectional study among a Japanese general adult population sample.

Methods

Japanese adults were recruited from the Japan Multi-Institutional Collaborative Cohort Study in the Okazaki area between 2012 and 2017. Second-hand smoke exposure and smoking status were assessed using a self-administered questionnaire. Based on their frequency of exposure to second-hand smoke, non-smokers and smokers were categorized as “almost never,” “sometimes,” and “almost every day”. Depressive symptoms were defined by a Kessler 6 score ≥5 points. We performed a multivariable Poisson regression analysis to obtain adjusted prevalence ratios (PRs) and 95% confidence intervals (CIs) for depressive symptoms.

Results

Overall, 5,121 participants (4,547 non-smokers and 574 smokers) were included whose mean age was 63.6 (standard deviation [SD], 10.3) years for non-smokers and 59.33 (SD, 10.2) years for smokers. The association between second-hand smoking and depressive symptoms was significant among non-smokers, but not among smokers. Among non-smokers, PRs compared with “almost never” were 1.25 (95% CI, 1.09–1.42) for “sometimes” and 1.41 (95% CI, 1.09–1.84) for “almost every day” (P for trend <0.001); among smokers, PRs compared with “almost never” were 1.30 (95% CI, 0.82–2.06) for “sometimes” and 1.44 (95% CI, 0.90–2.33) for “almost every day” (P for trend = 0.144).

Conclusions

Second-hand smoking and depressive symptoms were associated among non-smokers. Our findings indicate the importance of tobacco smoke control for mental health.

Physical Activity Earlier in Life Is Inversely Associated With Insulin Resistance Among Adults in Japan

Background

It is known that physical activity affects glucose metabolism. However, there have been no reports on the influence of physical activity earlier in life on subsequent glucose metabolism. Therefore, we analyzed the influence of physical activity in earlier decades of life on insulin resistance in middle aged and older residents in Japan.

Methods

The subjects were 6,883 residents of Okazaki City between the ages of 40 and 79 years who underwent physical examinations at the Okazaki City Medical Association Public Health Center from April 2007 through August 2011. They gave informed consent for participation in the study. Data on individual characteristics were collected via a questionnaire and from the health examination records. Fasting blood glucose and insulin levels were used to calculate the homeostatic model assessment of insulin resistance (HOMA-IR). HOMA-IR >1.6 was considered to indicate insulin resistance for the purpose of logistic regression models.

Results

The study sample included 3,683 men and 3,200 women for whom complete information was available. For those who exercised regularly throughout their teens to their 30s–40s, the odds ratio for having insulin resistance was 0.75 (95% confidence interval [CI], 0.58–0.96) for men and 0.76 (95% CI, 0.58–0.99) for women after adjusting for other variables, including age, body mass index, and present physical activity. A linear trend was also observed in both men and women.

Conclusions

Subjects who have exercised regularly in the early decades of life are less likely to have insulin resistance later in life.

Accuracy of self-reported height, weight and waist circumference in a Japanese sample

Objective

Inconsistent results have been found in prior studies investigating the accuracy of self‐reported waist circumference, and no study has investigated the validity of self‐reported waist circumference among Japanese individuals. This study used the diagnostic standard of metabolic syndrome to assess the accuracy of individual's self‐reported height, weight and waist circumference in a Japanese sample.

Methods

Study participants included 7,443 Japanese men and women aged 35–79 years. They participated in a cohort study's baseline survey between 2007 and 2011. Participants' height, weight and waist circumference were measured, and their body mass index was calculated. Self‐reported values were collected through a questionnaire before the examination.

Results

Strong correlations between measured and self‐reported values for height, weight and body mass index were detected. The correlation was lowest for waist circumference (men, 0.87; women, 0.73). Men significantly overestimated their waist circumference (mean difference, 0.8 cm), whereas women significantly underestimated theirs (mean difference, 5.1 cm). The sensitivity of self‐reported waist circumference using the cut‐off value of metabolic syndrome was 0.83 for men and 0.57 for women.

Conclusions

Due to systematic and random errors, the accuracy of self‐reported waist circumference was low. Therefore, waist circumference should be measured without relying on self‐reported values, particularly in the case of women.

Successful double autografts for patients with relapsed clear cell sarcoma of the kidney

Although the prognosis of clear cell sarcoma of the kidney (CCSK) has improved, when metastases occur the probability of cure is very low. We have treated two pediatric patients with relapsed CCSK, one with multiple bone metastases and another with brain metastases. After one or two courses of re-induction chemotherapy and radiation therapy to the sites of metastasis, they received double high-dose chemotherapy with autologous bone marrow rescue. Conditioning regimens were ifosphamide plus melphalan for the first autograft and busulfan plus thiotepa for the second. Hematological recovery was prompt, and no severe complications were observed. They are doing well without evidence of recurrence at 19 and 49 months after the second autograft, respectively.

Serum sialic acid and ankle versus brachial arterial-pressure ratio in NIDDM

Serum sialic acid is related to mortality from cardiovascular disease and is increased in patients with diabetic microangiopathies. The purpose of this study was to examine whether serum sialic acid is associated with ischemic disease of the lower extremities, using the ankle versus brachial arterial-pressure ratio. The subjects were NIDDM patients attending diabetic clinics. They received a questionnaire on smoking and duration of diabetes, and physical examinations including measurement of blood pressure of upper and lower extremities. Fasting blood was taken for measurement of sialic acid, total and HDL cholesterol, and HbA1c. Serum sialic acid was significantly correlated with ankle versus brachial arterial-pressure ratio (r = -0.32) and HbA1c (r=0.45). The correlation with ankle versus brachial arterial-pressure ratio was evident in the patients with low ankle versus brachial arterial-pressure ratios (r = -0.66), but was not significant in those with normal ankle versus brachial arterial-pressure ratios (r=0.16). The correlation with HbA1c was significant independently of ankle versus brachial arterial-pressure ratios. Mean serum sialic acid was higher in patients with very low ankle versus brachial arterial-pressure ratios (< 0.9) than in those with normal ankle versus brachial arterial-pressure ratios (> or = 1.0) or slightly low ankle versus brachial arterial-pressure ratios (0.9 approximately 1.0). These results suggest that serum sialic acid reflects the status of blood glucose control and the progression of ischemic disease of the lower extremities in NIDDM patients.

[Phase I Study of RA-700. RA-700 Clinical Study Group]

An antitumor substance, RA-700, isolated from Rubia akane or Rubia cordifolia has the novel structure. Phase I clinical study was conducted by the RA-700 clinical study group consisting of 6 institutions. A single dose administration and 5-day schedule administration were evaluated with 14 patients respectively. RA-700 was given from 0.2 to 1.4 mg/m2 in single i.v. dose study, from 0.4 to 2.0 mg/m2 in 5-day i.v. schedule study. Nausea and vomiting, fever, stomachache, mild hypotension and slight abnormality of electric-cardiogram were observed as the toxicities. In pharmacokinetic study, the elimination half-lives (t1/2) of RA-700 in plasma were 55 min, of alpha-phase and 3.9 hrs. of beta-phase by single dose study, and 23-25 min. of alpha-phase and 6-14 hrs. of beta-phase by 5-day schedule study. Accumulation was not found by 5-day schedule administration, and metabolite were not observed in plasma and urine. It seems that RA-700 is metabolized by the liver and excreted in the feces. In conclusion, the maximum tolerated dose was 1.4 mg/m2 for 5-day schedule administration.

[Fundamental and clinical studies of sulbactam/cefoperazone in the pediatric field]

Fundamental and clinical studies were carried out on sulbactam/cefoperazone (SBT/CPZ) in the field of pediatrics. The following results were obtained: A total of 185 clinical isolates that had been stocked at our department was employed to determine the minimum inhibitory concentrations (MICs) of SBT/CPZ against various bacterial species. SBT/CPZ showed strong antibacterial potency against E. coli, Salmonella, Klebsiella and P. mirabilis, and relatively strong potency against S. marcescens, P. aeruginosa and S. aureus. Antibacterial potency of SBT/CPZ was stronger than that of CPZ alone against E. coli, and it also showed strong activity against strains of Salmonella, S. marcescens and S. aureus, moderately or highly resistant to CPZ. SBT/CPZ was administered by intravenous bolus infusion to pediatric patients to determine the serum concentrations of SBT and CPZ. At a dose of 10 mg/kg the mean serum levels of SBT and CPZ were as follows; 17.8 micrograms/ml, 40.7 micrograms/ml at 15 minutes and 0.3 microgram/ml at 6 hours, respectively. The half-lives of SBT and CPZ in the serum were 1.05 hours and 1.76 hours, respectively. Similarly, at a dose of 20 mg/kg the mean serum levels of SBT and CPZ were; 31.9 micrograms/ml, 81.0 micrograms/ml at 15 minutes and 0.5 microgram/ml, 6.1 micrograms/ml at 6 hours, and the half-lives were 1.00 hour and 1.72 hours, respectively. At a dose of 40 mg/kg, only 1 case was determined. The serum levels of SBT and CPZ were 34.4 micrograms/ml, 74.8 micrograms/ml at 30 minutes and 0.2 microgram/ml at 6 hours, and the half-lives were 0.78 hour and 1.38 hours, respectively. SBT/CPZ was drip-infused intravenously over a period of 1 hour, and the serum concentrations of SBT and CPZ were determined. At the dose of 10 mg/kg or 20 mg/kg, the peak serum levels of SBT and CPZ were observed at 1 hour or at the end of drip infusion. At a dose of 10 mg/kg the mean serum levels of SBT and CPZ were 14.4 micrograms/ml, 33.7 micrograms/ml at 1 hour and 1.4 micrograms/ml, 4.6 micrograms/ml at 7 hours, respectively. The half-lives was 1.86 hours for SBT and 2.23 hours for CPZ, respectively. Similarly at a dose of 20 mg/kg, the mean serum levels of SBT and CPZ were, 22.2 micrograms/ml, 34.6 micrograms/ml at 1 hour and 0.5 microgram/ml, 2.8 micrograms/ml at 7 hours, and the half-lives was 1.17 hours and 1.75 hours, respectively. The urinary recovery rate was determined for the 6 hours period after administration.(ABSTRACT TRUNCATED AT 400 WORDS)

[Basic and clinical studies on ceftazidime in the pediatric field]

Basic and clinical studies were made on ceftazidime (CAZ) in pediatric field, and the following results were obtained. The antibacterial activity of CAZ against clinically isolated and maintained strains was examined. CAZ was unequivocally more active than CEZ and CMZ against Gram-negative rods, with MIC distribution similar to that of CTX, except for that for P. aeruginosa. The MIC of CAZ was lower than that of CTX for P. aeruginosa. Compared with the MICs of CEZ, CMZ and CTX, CAZ showed slightly higher MICs for Gram-positive bacteria. The blood concentrations of CAZ, at 0.25, 0.5, 1, 2, 4 and 6 hours after a one shot intravenous injection of 10 mg/kg of CAZ were 64.9, 36.9, 28.3, 14.7, 4.92 and 2.42 micrograms/ml, respectively, with the half-life of 1.27 hours. The blood concentrations of CAZ, at 0.25, 0.5, 1, 2, 4 and 6 hours after a 1-hour drip infusion of 10 mg/kg of CAZ were 16.6, 24.5, 41.4, 17.1, 5.38 and 2.62 micrograms/ml, respectively, with the half-life of 1.28 hours. The blood concentrations of CAZ, at 0.25, 0.5, 1, 2, 4 and 6 hours after a one shot intravenous injection of 20 mg/kg of CAZ were 73.1, 60.8, 39.3, 17.3, 8.23 and 4.45 micrograms/ml, respectively, with the half-life of 1.42 hours. The blood concentrations of CAZ, at 0.5, 1, 2, 4 and 6 hours after a 1-hour drip infusion of 20 mg/kg of CAZ were 55.1, 69.0, 32.1, 11.4 and 4.56 micrograms/ml, respectively, with the half-life of 1.27 hours. Urinary recovery rate of CAZ during the first 6 hours after a one shot intravenous injection of 10 mg/kg of CAZ was 86.7%. CAZ was administered to 17 children with infections, and the clinical response was excellent or good in 94%. CAZ was bacteriologically effective in 14 patients, all bacteria having been eradicated in them. The bacteria were E. coli in 10 patients, H. influenzae in 2, P. aeruginosa in 1 and S. pneumoniae in 1. As for side effects, slight elevation in GOT was observed in 1 case and eosinophilia, in another case.

[Experimental and clinical evaluation of cefpiramide in pediatrics]

Fundamental and clinical studies on cefpiramide (CPM), a new semisynthetic cephalosporin, were made and the following results were obtained. The antibacterial activities of CPM against clinical isolates were almost similar to those of conventional cephems except for Pseudomonas aeruginosa. The antibacterial activity of CPM against P. aeruginosa was excellent and superior than those of the others. Ten or twenty mg/kg of CPM was given intravenously at one shot to 11 cases. The mean serum levels of CPM reached 231 micrograms/ml at 15 minutes, 119 micrograms/ml at 30 minutes, 88 micrograms/ml at 1 hour, 65 micrograms/ml at 2 hours and 33 micrograms/ml at 6 hours after administration at a single dose of 10 mg/kg, respectively with the half-life of 3.42 hours. In case of 20 mg/kg, the mean serum levels attained 306 micrograms/ml at 15 minutes, 245 micrograms/ml at 30 minutes, 160 micrograms/ml at 1 hour, 118 micrograms/ml at 2 hours and 66 micrograms/ml at 6 hours respectively after administration with the half-life of 5.20 hours. CPM was given intravenously to 12 patients with various bacterial infections. The clinical effects were excellent in 5 cases, good in 6 cases and poor in 1 case and the effective rate was 92%. No side effect was observed in all cases.

[Experimental and clinical studies of an ampicillin suppository (KS-R1) in pediatrics]

Blood levels of ampicillin (ABPC) were measured in 10 childish patients with heart disease after the rectal administration of KS-R1 at doses of 125 mg and 250 mg. Average blood levels of ABPC at 15, 30 minutes, 1, 2 hours and 4 hours after the administration of KS-R1 were 6.8, 6.9, 3.1, 1.1 mcg/ml and 0.1 mcg/ml with half-life of 0.64 hours in patients of age from 1 year to 4 years 7 months old (dose level 8.9 approximately 13.9 mg/kg, average 10.5 mg/kg), and 5.2, 6.1, 3.4, 1.0 mcg/ml and 0.1 mcg/ml with half-life of 0.65 hours in patients of age from 7 years 10 months to 10 years 7 months old (dose level 8.3 approximately 13.9 mg/kg, average 9.8 mg/kg), respectively. Clinical effective rate (excellent and good) was 87% in 55 childish patients with infections. Bacteriologically, 13 strains (74%) out of 18 strains which were isolated from the patients were eradicated. No severe side effects were observed. Diarrhea was observed in 3 cases.

[Experimental and clinical evaluation of cefotetan in pediatrics]

Preclinical studies were carried out on cefotetan (CTT), together with clinical studies in the field of pediatrics. The following results were obtained. A total of 114 clinical isolates that have been stored in the authors' department was employed to determine the minimum inhibitory concentrations (MICs) of CTT against various bacterial species. Against E. coli, Salmonella, K. pneumoniae and P. mirabilis, the MICs of CTT showed a peak at 0.78 micrograms/ml, and most of the strains were inhibited by a CTT concentration of 6.25 micrograms/ml or less. The MICs for S. marcescens strains showed a peak at 25 micrograms/ml, with 25% of the strains having MICs of 3.13 micrograms/ml or less, and 67% having MICs of 25 micrograms/ml or more. All of the P. aeruginosa strains had MICs of over 100 micrograms/ml. Against all of the tested strains of S. aureus, a Gram-positive bacterium, CTT showed MICs of 12.5 micrograms/ml or more, while all of the strains of S. faecalis were found to have MICs of over 100 micrograms/ml. CTT was administered intravenously to pediatric patients as a bolus injection, and then the concentration of the antibiotic in the serum was determined as a function of time. When the dosage rate was 10 mg/kg, the mean serum levels were as follows; 58.2 micrograms/ml at 30 minutes, 45.5 micrograms/ml at 1 hour, 33.6 micrograms/ml at 2 hours, 18.0 micrograms/ml at 4 hours and 11.7 micrograms/ml at 6 hours after the injection. The half-life of CTT in the serum at this dosage was thus 2.40 hours. Similarly, at a dosage rate of 20 mg/kg, the mean values at the various times were; 98.6 micrograms/ml at 30 minutes, 75.6 micrograms/ml at 1 hour, 57.8 micrograms/ml at 2 hours, 35.5 micrograms/ml at 4 hours and 23.2 micrograms/ml at 6 hours subsequent to the injection. The half-life of CTT in the serum in these cases was 2.73 hours. CTT was drip-infused intravenously over a period of 1 hour, and then the serum concentration of the drug was monitored with the passage of time. Subsequent to the administration of 10 mg/kg, the mean serum concentrations were as follows; 48.8 micrograms/ml at 30 minutes, 81.5 micrograms/ml at 1 hour, 42.2 micrograms/ml at 2 hours, 23.6 micrograms/ml at 4 hours and 14.8 micrograms/ml at 6 hours subsequent to the injection. The half-life of CTT in the serum after this intravenous drip infusion was thus 2.13 hours.(ABSTRACT TRUNCATED AT 400 WORDS)

[Pharmacokinetics study on gentamicin intravenous drip infusion in children]

Pharmacokinetics of gentamicin in children after intravenous infusion over 60 minutes were compared with that after intramuscular injection. 1. Mean measured peak serum levels after intravenous infusion of 2.5 mg/kg and intramuscular injection of 2.0 mg/kg were 6.1 micrograms/ml at termination of infusion and 6.5 micrograms/ml at 30 or 60 minutes after injection, respectively. Older children showed higher serum levels. 2. There was no difference in serum half-life between both modes of administration. 3. The AUC after intravenous infusion was slightly larger than that after intramuscular injection. 4. It was suggested that the efficacy and safety of the treatment by intravenous infusion in children are comparable to that by the intramuscular injection, and optimum single dose is 1.5--2.5 mg/kg.

[Basic and clinical studies on cefmenoxime in pediatric field]

Basic and clinical studies were made on cefmenoxime (CMX) in pediatric field, and the following results were obtained. 1. The antibacterial activity of CMX against clinically isolated and maintained strains was examined. CMX had stronger antibacterial activity than CEZ against Escherichia coli, Salmonella, Klebsiella pneumoniae, Proteus mirabilis, Serratia marcescens and Pseudomonas aeruginosa, but CEZ had stronger antibacterial activity against Staphylococcus aureus. 2. The blood concentrations of CMX, 0.5, 1, 2, 4 and 6 hours after a one-shot intravenous injection of 20 mg/kg of CMX were 33.6, 15.1, 4.5, 2.5 and 0.6 mcg/ml, respectively, with the half-life of 1.04 hours. 3. The blood concentrations of CMX, 0.5, 1, 2, 4 and 6 hours after a 1-hour intravenous drip infusion of 20 mg/kg of CMX were 32.0, 55.2, 8.4, 4.2 and 1.0 mcg/ml, respectively, with the half-lite of 0.96 hour. 4. A complete or partial clinical response to therapy with CMX was obtained in all 10 children with infectious diseases. 5. Bacteriological examination made on 3 patients showed that all bacteria had been eradicated, and that therapy was effective. The bacteria were E. coli in 2 patients and Proteus mirabilis in 1 patient. 6. The side effects produced were neutropenia, eosinophilia and skin eruption in 1 patient, and diarrhea in 1 patient.

[Fundamental and clinical evaluation of 9,3"-diacetylmidecamycin in pediatric field (author's transl)]

1. The dry syrup of MOM was administered orally to 17 patients mainly with heart diseases at doses of 10 mg/kg and 20 mg/kg. In 17 cases, the serum level was measured and in 4 cases, the urinary excretion rate including the metabolites of MOM. 2. The mean maximal concentrations were 0.54 mcg/ml at 30 minutes for the group of 10 mg/kg treatment and 0.33 mcg/ml at 1 hour for the group of 20 mg/kg treatment. The dose response was not observed obviously in both groups. 3. In each of the cases, the sum of excretion rates of metabolites in the 24-hour urine was about 1%. 4. MOM was administered clinically to 39 cases with respiratory tract infections and the overall efficacy rate was 85%. 5. In this study, 5 strains of S. pyogenes were isolated and the eradication rate was 60%. 6. Although severe side effects were not observed, gastrointestinal abnormalities like diarrhea and vomiting were seen in 3 cases. 7. Any pediatric patient did not refuse taking.