The clinical pharmacokinetics of a new pharmacokinetically enhanced formulation of amoxicillin/clavulanate

BACKGROUND

A new oral pharmacokinetically enhanced formulation of the broad-spectrum antibiotic amoxicillin/clavulanate has been developed to provide more effective therapy against resistant pathogens than is provided by currently available formulations by maintaining therapeutically useful plasma amoxicillin concentrations for a longer period after dosing.

OBJECTIVE

This study explored the pharmacokinetics of the new oral formulation of amoxicillin/clavulanate in healthy male and female subjects.

METHODS

A single oral dose of pharmacokinetically enhanced amoxicillin/clavulanate (2000/125 mg; 16:1 ratio) was administered to subjects at the start of a meal. After dosing, blood samples were collected at frequent intervals up to 12 hours, and plasma was assayed for amoxicillin and clavulanate concentrations using validated procedures. The new formulation consisted of 1 layer of immediate-release amoxicillin and clavulanate and another of sustained-release amoxicillin in a proportion such that for an amoxicillin minimum inhibitory concentration (MIC) of 4 microg/mL, the time above the MIC (T >MIC) would be approximately > or = 40% over a 12-hour dosing interval.

RESULTS

The study enrolled 24 and 31 healthy male and female subjects, respectively. Their mean age was 35 years (range, 18-58 years) and mean body weight was 69 kg (range, 51-86 kg). After the expected sharp peak in plasma amoxicillin concentration, there appeared to be a slower decline with the pharmacokinetically enhanced formulation than is usually seen with conventional formulations, and there was evidence of a second amoxicillin absorption phase. The mean T >MIC for an amoxicillin MIC of 4 microg/mL was 49.4% of a 12-hour dosing interval, a value that cannot be achieved with existing approved doses and formulations of amoxicillin/clavulanate. By 12 hours, plasma amoxicillin concentrations were very low (approximately 0.05 microg/mL), suggesting no expectation of notable dose-to-dose accumulation on repeat dosing with a BID regimen. The terminal half-lives of amoxicillin (1.27 hours) and clavulanate (1.03 hours) with the new formulation were similar to those of existing formulations of amoxicillin/clavulanate. No deaths or serious adverse events were reported.

CONCLUSIONS

The enhanced pharmacokinetic profile of amoxicillin/clavulanate seen in this study suggests that this formulation is likely to be highly effective for the oral treatment of infections caused by bacteria--including beta-lactamase-producing organisms--and strains with amoxicillin MICs < or = 4 microg/mL.

Triggers that prompt people with urinary symptoms to seek help

Urinary symptoms are fairly common among the adult population yet only a small percentage report them as bothersome. There are many reasons why people do not seek help for urinary symptoms, e.g. the embarrassment felt by those experiencing them. Little research, however, has looked at the reasons why some people seek healthcare professional help for urinary symptoms. This article describes a study aimed to identify the triggers that prompt a person with urinary symptoms to seek help. The findings suggest that health promotion campaigns play an important role in both raising awareness and demand for services. Furthermore, this study highlights the personal and social reasons why people seek help for urinary symptoms. It is important, therefore, that healthcare professionals take these personal and social circumstances into account when carrying out any assessment to ensure that a successful management of symptoms is achieved.

First example of anti-Kx in a person with the McLeod phenotype and without chronic granulomatous disease

BACKGROUND

Kx is lacking in the RBCs of patients with the McLeod syndrome. This condition is sometimes associated with chronic granulomatous disease (CGD). If given allogeneic RBCs, CGD patients with the McLeod phenotype may produce anti-Kx and anti-Km, and only phenotypically matched McLeod blood would be compatible. McLeod phenotype persons without CGD have made anti-Km but not anti-Kx (2 examples), and thus both McLeod and K(O) blood would be compatible.

CASE REPORT

RBCs from a transfused patient with the McLeod phenotype but not with CGD (non-CGD McLeod) were typed for the Kell blood group antigens, and the plasma was analyzed for the presence of antibody by agglutination. The molecular basis was determined by analyzing for XK protein on RBC membranes by Western immunoblotting, by sequencing the XK gene, and by RFLP.

RESULTS

The RBCs did not react with anti-Kx + anti-Km and showed weakening of Kell system antigens. The patient's plasma reacted moderately (2+) with RBCs of common Kell type and strongly (4+) with K(O) RBCs and RBCs of common Kell type treated with dithiothreitol, and did not react with McLeod RBCs. XK protein was absent from the RBC membranes. The XK gene had a point mutation in the donor splice site of intron 1 (G>C).

CONCLUSION

This is the first report describing the molecular alteration in a non-CGD McLeod patient who has made anti-Kx. The immune response of people with the McLeod phenotype can vary, and K(O) blood may not always be compatible.

An epidemiological study to establish the prevalence of urinary symptoms and felt need in the community: the Leicestershire MRC Incontinence Study. Leicestershire MRC Incontinence Study Team

BACKGROUND

The aim of the study was to establish the prevalence of urinary symptoms and felt need in adults. This paper discusses problems with setting thresholds to distinguish cases from non-cases in this field of research. Few studies have provided detailed age- and sex-specific prevalence estimates for felt need in relation to urinary symptoms.

METHODS

A cross-sectional postal survey was carried out of 15,904 community-dwelling adults aged 40 years or more registered with general practitioners in Leicestershire. Subjects were selected randomly by household from the Leicestershire Health Authority Register. The postal questionnaire consisted of questions on general health, urinary and bowel symptoms, quality of life, service use and demographic characteristics.

RESULTS

Thirty-four per cent of the sample reported clinically significant symptoms. The prevalence and severity of symptoms increased with age. However, only 2 per cent of the sample reported symptoms that were clinically significant, bothersome and socially disabling.

CONCLUSION

Urinary symptoms are very common in adults over 40 years of age living in the community. However, symptom-based estimates probably overestimate the level of need for health care in the community. It may be more effective and efficient to target services, in the first instance, on those people who report clinically significant symptoms that are bothersome or socially disabling. A consensus on thresholds and definitions of urinary symptoms is required to standardize clinical and research work and to target services more appropriately.

Non-invasive assessment of rejection in pediatric transplant patients: serologic and echocardiographic prediction of biopsy-proven myocardial rejection

BACKGROUND

Cardiac allograft rejection is a multifocal immune process that is currently assessed using biopsy-guided histologic classification systems (International Society for Heart and Lung Transplantation). Cardiac troponin T and I are established serologic markers of global myocyte damage. The use of load-independent measures of contractility have also been shown to accurately assess the presence of ventricular dysfunction. Little is known about their utility in accurately predicting rejection in the pediatric age group. We undertook the present study to compare rejection grade with echocardiographic and serologic estimates of transplant rejection-related myocardial damage.

METHODS

We compared histologic rejection grades (0 to 4) with patient characteristics, echocardiographic measurements, catheterization measurements, and biochemical markers for 86 evaluations in 37 transplant recipients at Children's Hospital.

RESULTS

In univariate analyses, biopsy scores correlated (p < 0.05) inversely with left ventricular systolic function (shortening fraction) and contractility (stress velocity index, SVI), and directly with mitral E-wave amplitude. In multivariate analyses, lower contractility and higher mitral E-wave amplitude remained significantly (p < or = 0.01) associated with rejection (SVI, p = 0.002, odds ratio = 0.393; E wave, p = 0.0002, odds ratio = 228). Most rejection episodes were associated with elevation of biochemical markers of myocardial injury. Although troponin I was weakly associated with differences between rejection grades (p = 0.034), troponin T, creatine kinase-MB fraction, and C-reactive protein did not differ with biopsy-rejection scores. Serum markers had a poor predictive capacity for biopsy-detected rejection. Troponin T and I did correlate with increased left ventricular wall thickness and mass.

CONCLUSION

Progressively depressed left ventricular contractility and diastolic function are found with worsening pediatric heart transplant rejection-biopsy score; however, sensitive and specific serum markers do not correspond to the degree of active myocardial injury. The use of echocardiographic measures of contractility is associated with a specificity of 91.8% but low sensitivity of 66.7%. Overall we found poor concordance between serum markers and grade of rejection. It is unclear whether myocardial injury as assessed by serum markers, echocardiography, or histologic scoring is more important for assessment of acute rejection or long-term outcome, but it does not appear that serum and tissue markers of rejection can be used interchangeably.

Development, implementation and evaluation of a new nurse-led continence service: a pilot study

The Leicestershire Medical Research Council (MRC) Incontinence Study is a series of interrelated studies exploring the epidemiology of urinary symptoms, including incontinence, and evaluating service provision and treatment options for these symptoms. This paper describes one aspect of the Leicestershire MRC Incontinence Study, namely the development, implementation and evaluation of a new nurse-led continence service. When developing a new service it is important to determine its acceptability and suitability to the target population. The new mode of service delivery was dependent on specially trained Continence Nurse Practitioners (CNP) delivering predefined evidence-based treatment interventions. Objective and subjective outcome measures were used to evaluate the service. The service was shown to be effective in reducing urinary symptoms and led to high levels of patient satisfaction. This service is currently being evaluated in a randomized controlled trial.

Transmission of response to trauma? Second-generation Holocaust survivors' reaction to cancer

OBJECTIVE

Opinions differ about the effects of the Holocaust on the adult offspring of survivors. The authors studied cancer patients who were second-generation Holocaust survivors in an attempt to determine whether they react to their illness with the high distress found to be a characteristic of Holocaust survivors.

METHOD

In a study population of women with breast cancer, 106 second-generation Holocaust survivors were compared to 102 women whose parents were not in the Holocaust. Background information was obtained by interviews. In addition, all patients completed three self-reports: the Mental Attitude to Cancer Scale, the Brief Symptom Inventory, and the Impact of Event Scale.

RESULTS

The two groups had identical mean scores on the Mental Attitude to Cancer Scale. The offspring of Holocaust survivors had scores on the Brief Symptom Inventory and the Impact of Event Scale that were substantially and significantly higher and in the range of psychopathology. Within the group, married women and women whose mothers were still alive were even more distressed. Other independent variables shed little light on why the second-generation Holocaust survivors suffered from extreme distress.

CONCLUSIONS

Second-generation Holocaust survivors are particularly vulnerable to psychological distress and, when faced with a trauma such as breast cancer, react with extreme psychological distress.

Co-expression in Helicobacter pylori of cagA and non-opsonic neutrophil activation enhances the association with peptic ulcer disease

AIMS

To investigate the association of cagA positivity and non-opsonic neutrophil activation capacity in wild-type Helicobacter pylori strains with peptic ulcer disease or chronic gastritis only.

METHODS

Helicobacter pylori were isolated from antral biopsies of 53 consecutive patients with chronic antral gastritis, of whom 24 had peptic ulcer disease endoscopically. The presence of cagA, a marker for the cag pathogenicity island, was determined by polymerase chain reaction with specific oligonucleotide primers, and non-opsonic neutrophil activation capacity by luminol enhanced chemiluminescence.

RESULTS

The cagA gene was present in 39 of 53 (73.6%) strains, 20 of which (83.3%) were from the 24 patients with peptic ulcer disease and 19 (65.5%) from the 29 patients with chronic gastritis only. Non-opsonic neutrophil activation was found in 29 (54.7%) strains, 16 of which (66.7%) were from patients with peptic ulcer disease, and 13 (44.8%) from those with chronic gastritis. Non-opsonic neutrophil activation was found more frequently in cagA+ than cagA- strains (59% v 42.9%). Whereas four of the 14 cagA- strains and eight of the 24 non-opsonic neutrophil activation negative strains were from patients with peptic ulcer disease, only two of 24 (8.3%) peptic ulcer disease strains expressed neither cagA nor non-opsonic neutrophil activation. The cagA gene and non-opsonic neutrophil activation capacity were co-expressed in 14 of 24 (58.3%) strains from patients with peptic ulcer disease, and in nine of 29 (31%) strains from individuals with chronic gastritis.

CONCLUSIONS

Positivity for cagA and non-opsonic neutrophil activation occur independently in wild-type H pylori strains. However, co-expression of the two markers enhanced the prediction of peptic ulcer disease.

The role of clinical suspicion in evaluating a new diagnostic test for active tuberculosis: results of a multicenter prospective trial

CONTEXT

In laboratory trials, nucleic acid amplification tests for the diagnosis of tuberculosis (TB) are more accurate than acid-fast bacilli (AFB) smear microscopy and are faster than culture. The impact of these tests on clinical diagnosis is not known.

OBJECTIVE

To assess the performance of a nucleic acid amplification test, the enhanced Mycobacterium tuberculosis Direct (E-MTD) test, against a uniform clinical standard stratified by level of clinical suspicion.

DESIGN

Prospective multicenter trial conducted between February and December 1996, documenting the clinical suspicion of TB at enrollment and using final comprehensive diagnosis as the criterion standard.

SETTING

Six urban medical centers and 1 public health TB clinic.

PATIENTS

A total of 338 patients with symptoms and signs consistent with active pulmonary TB and complete clinical diagnosis were stratified by the clinical investigators to be at low (< or =25%), intermediate (26%-75%), or high (>75%) relative risk of having TB.

MAIN OUTCOME MEASURES

Sensitivity, specificity, and positive and negative predictive values of the E-MTD test in clinical suspicion of groups with low (n = 224); intermediate (n = 68); and high (n = 46) clinical suspicion of TB.

RESULTS

Based on comprehensive clinical diagnosis, sensitivity of the E-MTD test was 83%, 75%, and 87% for low, intermediate, and high clinical suspicion of TB, respectively, and corresponding specificity was 97%, 100%, and 100% (P = .25). Positive predictive value of the E-MTD test was 59% (low), 100% (intermediate), and 100% (high) compared with 36% (low), 30% (intermediate), and 94% (high) for AFB smear. Corresponding negative predictive values were 99%, 91%, and 55% [corrected] (E-MTD test) vs 96%, 71%, and 37% (AFB smear).

CONCLUSIONS

For complex diagnostic problems like TB, clinical risk assessments can provide important information regarding predictive values more likely to be experienced in clinical practice. For this series, a clinical suspicion of TB was helpful in targeting areas of the clinical spectrum in which nucleic acid amplification tests can make an important contribution.

Effect of creatine loading on neuromuscular fatigue threshold

The purpose of this investigation was to determine the effect of creatine (Cr) loading on the onset of neuromuscular fatigue by monitoring electromyographic fatigue curves from the vastus lateralis muscle using the physical working capacity at the fatigue threshold (PWC(FT)) test. Using a double-blind random design, 15 women athletes [mean age 19.0 +/- 2.0 (SD) yr] from the university crew team received a placebo (n = 8; 20 g glucose) or Cr (n = 7; 5 g Cr monohydrate + 20 g glucose) four times per day for 5 consecutive days. Analysis of covariance was used to analyze the data (covaried for presupplementation PWC(FT) values). The adjusted mean postsupplementation PWC(FT) value for the Cr group (mean = 186 W) was significantly (P < 0.05) higher than that of the placebo group (mean = 155 W). These findings suggest that Cr loading may delay the onset of neuromuscular fatigue.

The airway longitudinal elastic fiber network and mucosal folding in patients with asthma

A submucosal network of elastic fibers in a collagen and myofibroblast matrix form discrete longitudinal bundles (LB) in the bronchial tree. The LB may affect airway function by altering the mechanical properties of the airway wall or by changing the folding behavior of the airway mucosa. The area and number of LB were quantified from 12 cases each of fatal asthma (FA), nonfatal asthma (NF), and nonasthmatic (NA) control cases on elastic-trichrome stained airways. The effects of group, sex, age, and smoking were examined using multiple linear regression. The area fraction of LB increased (p < 0.05) approximately twofold in cases of FA compared with NA control cases in both large and small airways. The areas of LB were increased in smokers, older subjects, and men (p < 0.05). The number of mucosal folds was related to the number of longitudinal bundles in asthmatics and nonasthmatics and was not different between groups. Collagen and myofibroblasts were increased (p < 0.05) in LB of FA and NF cases compared with NA control cases. The increased size and altered composition of LB in asthma may influence airway function; however, excessive airway narrowing in asthma is not due to altered numbers of mucosal folds.

Prospective survey to verify the Ottawa ankle rules

OBJECTIVE

To determine if the Ottawa ankle rules are valid in the setting of an urban teaching hospital in the UK.

DESIGN

A prospective survey.

SETTING

Accident and emergency department, Western Infirmary, Glasgow from 1 April 1995 to 31 August 1995.

SUBJECTS

800 patients with an acute ankle injury.

RESULTS

800 patients were used for analysis of which 584 (73%) were radiographed; 70 (12%) had fractures, 63 (10.8%) of which were significant. Four of these patients with fractures fulfilled none of the Ottawa ankle rules criteria for plain radiography.

CONCLUSION

Application of the Ottawa ankle rules to this group of patients would have produced a sensitivity of 93.6%. Although useful, decision rules should be used with care and not replace clinical judgment and experience.

Long terminal repeat sequences of equine infectious anaemia virus are a major determinant of cell tropism

The Wyoming strain of equine infectious anaemia virus (EIAV) is a highly virulent field strain that replicates to high titre in vitro only in primary equine monocyte-derived macrophages. In contrast, Wyoming-derived fibroblast-adapted EIAV strains (Malmquist virus) replicate in primary foetal equine kidney and equine dermis cells as well as in the cell lines FEA and Cf2Th. Wyoming and Malmquist viruses differ extensively both in long terminal repeat (LTR) and envelope region sequences. We have compared the promoter activities of the Wyoming LTR with those of LTRs derived from fibroblast-adapted viruses by examining their abilities to drive a luciferase reporter gene as well as by construction of infectious molecular clones differing only in LTR sequence. Our results indicate that LTR sequences are a major restriction for growth of the Wyoming strain of EIAV in fibroblasts.

The role of religious and spiritual beliefs in coping with malignant melanoma: an Israeli sample

This preliminary study examined the possible relationship between a newly developed instrument, the Spiritual Beliefs Inventory (SBI-54), and the coping style of a group of cancer patients in Israel. The sample consisted of 100 malignant melanoma patients diagnosed at stages I and II, A and B. Patients were individually interviewed at home and completed seven self-reports. The present report focuses on the relationship of the SBI-54 with other measures of coping, psychological distress and social support. Findings showed that there was a significantly positive correlation between the SBI-54 and the active-cognitive coping style (r = 0.48, p < 0.01).

Cancer in married couples: higher or lower distress?

This study focuses on the question of what occurs when both spouses become seriously ill. Our hypothesis was that psychological distress in married couples involving two ill partners is far higher than when only one partner is ill. The study group comprised 20 married couples, in which both spouses were diagnosed with cancer. Two comparison groups were also studied: 20 married couples with the husband diagnosed with cancer, and 20 couples with the wife diagnosed with cancer. All patients in the three groups completed four self-report scales: the Brief Symptom Inventory (BSI); the Perceived Family Support (PFS); the Impact of Events Scale (IES); and the Mental Adjustment to Cancer (MAC). The healthy spouses completed only the first three scales. Our findings supported the null hypothesis--that is, that the psychological distress in married couples with both partners diagnosed with cancer was not significantly different than when only one partner had cancer. Our findings also showed that neither sociodemographic background, medical condition, nor family support affect patient distress. Gender differences were found with Intrusiveness contributing to the distress of male, but not female, patients. This study confirms and augments earlier work, and shows that partners of cancer patients report a high degree of distress, with this level of distress not being much different from that of the patients.