International study comparing cefdinir and cefuroxime axetil in the treatment of patients with acute exacerbation of chronic bronchitis

OBJECTIVES

To assess the efficacy and tolerability of three antibiotic regimens in patients with acute exacerbation of chronic bronchitis.

METHODS

In this double-blind, randomized, multicentered, parallel-group study, patients received once-daily cefdinir 600 mg, twice-daily cefdinir 300 mg, or twice-daily cefuroxime axetil 250 mg for 10 days. Primary efficacy measures were microbiologic eradication rate, by pathogen and by patient, and clinical response rate, by patient.

RESULTS

Of 1045 patients, 589 were evaluable for efficacy. At baseline, most patients had moderate or severe cough and sputum production as well as rhonchi, wheezing, and dyspnea. The microbiologic eradication rates by pathogen were 90% with once-daily cefdinir, 85% with twice-daily cefdinir, and 88% with twice-daily cefuroxime. The corresponding values for microbiologic eradication rate by patient were 90% (once-daily cefdinir), 85% (twice-daily cefdinir), and 86% (twice-daily cefuroxime). The respective clinical response rates by patient were 81%, 74%, and 80%. There were no significant differences in the incidence of drug-related adverse events or discontinuations due to adverse events. Diarrhea was the most frequent complaint.

CONCLUSIONS

The results indicate that the efficacy and tolerability of cefdinir, once or twice daily, and cefuroxime were comparable with no significant differences between the regimens used.

Effects of house dust mite avoidance measures on Der p 1 concentrations and clinical condition of mild adult house dust mite-allergic asthmatic patients, using no inhaled steroids

BACKGROUND

Exposure to house dust mite (HDM) allergens often results in worsening of asthma. Therefore, avoidance of exposure to HDM allergens is often proposed. Unfortunately, the most effective and feasible avoidance strategy is still not completely assessed. Consequently, we investigated the effects of a combined HDM avoidance strategy on HDM allergen concentrations and clinical condition of allergic, mild asthmatic, patients using no inhaled steroids.

METHODS

Asthmatic patients, allergic to HDM, using no inhaled corticosteroids, were randomly allocated to an active (n = 76) or a placebo allergen-avoidance group (n = 81). Avoidance measures consisted of applying Acarosan(R) (placebo: water) to the living room and bedroom floors, and the use of HDM-impermeable covers for mattresses and bedding (placebo: cotton covers for mattresses only). Effects on allergen concentrations (Der p 1), FEV1, bronchial hyperresponsiveness, peak flow parameters and asthma symptom scores were studied during 20 weeks and controlled for the allergic status of the patients.

RESULTS

The active covers reduced Der p 1 concentrations to 9.4% (P = 0.0001), and were always significant lower than in the placebo group (P = 0.0002). Acarosan(R) resulted in slight but significant decreases (twofold, P = 0.0001), both on living room and bedroom floors, but concentrations were never significantly lower than the placebo group. Although the combined avoidance strategy resulted in a considerable reduction in allergen load in the active group, no differences were seen between the two groups in any of the clinical parameters during the follow-up period in this group of allergic asthmatics, using no inhaled corticosteroids. Corrections for the allergic status did not alter these results.

CONCLUSIONS

The combined avoidance strategy was effective in reducing HDM allergen concentration. This was especially achieved by the allergen-impermeable covers, while the effects of Acarosan(R) were only marginal. However, this allergen reduction was not reflected in a convincing improvement in clinical condition in this group of mild allergic asthmatics, using no inhaled steroids. Perhaps, a longer follow-up period would have resulted in more pronounced effects.

Long-term effects of clenbuterol on diaphragm morphology and contractile properties in emphysematous hamsters

The aim of the present study was to investigate the effect of chronic long-term clenbuterol treatment (1 mg/kg subcutaneously twice a day for 12 wk) on diaphragm morphology and function in emphysematous (EH) and normal hamsters (NH). Clenbuterol increased body weight, diaphragm weight, and skeletal muscle weight in both EH and NH to a similar extent. In the diaphragm, clenbuterol significantly increased myosin heavy chain type I, IIa, and IIx muscle fiber cross-sectional areas by approximately 35-55% in both EH and NH. This response to clenbuterol treatment was not significantly different between EH and NH diaphragm. In EH, twitch force (Pt), maximal tetanic force, and force-frequency curve were significantly reduced compared with NH. In EH, clenbuterol increased Pt by approximately 10%, restoring Pt to NH level. A similar improvement was observed in the force-frequency characteristics. Clenbuterol did not alter contractile properties in NH. In conclusion, long-term clenbuterol treatment resulted in an increased size of all diaphragm muscle fiber types in both NH and EH. Clenbuterol completely abolished the reduced force generation induced by emphysema.

Anabolic steroids in part reverse glucocorticoid-induced alterations in rat diaphragm

Animal and clinical studies have shown respiratory muscle dysfunction caused by treatment with glucocorticoids. The present study was designed to investigate whether anabolic steroids are able to antagonize the loss of diaphragm force induced by long-term low-dose methylprednisolone (MP) administration. Male adult rats were randomized to receive saline or MP (0.2 mg . kg-1 .day-1 sc) during 9 mo, with or without nandrolone decanoate (ND; 1 mg . kg-1 . wm -1 im) during the last 3 mo. The approximately 10% reduction in force generation of isolated diaphragm bundles induced by MP was completely abolished by addition of ND. The MP-induced decrease in number of fibers expressing type IIb myosin heavy chains was not reversed by ND. MP slightly reduced type I, IIa, and IIx fiber cross-sectional areas (CSA), but not type IIb fiber CSA. Addition of ND abolished the reduction in IIa and IIx fiber CSA. The MP-induced alterations in glycogenolytic activity and fatty acid oxidation capacity were not reversed by ND. In conclusion, the marked reduction in diaphragm force caused by long-term low-dose MP was completely abolished by addition of ND. ND in part also antagonized the effects of MP on diaphragm morphology but showed no beneficial effects on biochemical changes.

Training with supplemental oxygen in patients with COPD and hypoxaemia at peak exercise

Supplemental oxygen has acute beneficial effects on exercise performance in patients with chronic obstructive pulmonary disease (COPD). The purpose of this study was to investigate whether oxygen-supplemented training enhances the effects of training while breathing room air in patients with severe COPD. A randomized controlled trial was performed in 24 patients with severe COPD who developed hypoxaemia during incremental cycle exercise (arterial oxygen saturation (Sa,O2) <90% at peak exercise). All patients participated in an in-patient pulmonary rehabilitation programme of 10 weeks duration. They were assigned either to general exercise training while breathing room air (GET/RA group: forced expiratory volume in one second (FEV1) 38% of predicted; arterial oxygen tension (Pa,O2) 10.5 kPa at rest; Pa,O2 7.3 kPa at peak exercise), or to GET while breathing supplemental oxygen (GET/O2 group: FEV1 29% pred; Pa,O2 10.2 kPa at rest; Pa,O2 7.2 kPa at peak exercise). Sa,O2 was not allowed to fall below 90% during the training. The effects on exercise performance while breathing air and oxygen, and on quality of life were compared. Maximum workload (Wmax) significantly increased in the GET/RA group (mean (SD) 17 (15) W, p<0.01), but not in the GET/O2 group (7 (25) W). Six minute walking distance (6MWD), stair-climbing, weight-lifting exercise (all while breathing room air) and quality of life significantly increased in both groups. Acute administration of oxygen improved exercise performance before and after training. Training significantly increased Wmax, peak carbon dioxide production (V'CO2) and 6MWD while breathing oxygen in both groups. Differences between groups were not significant. Pulmonary rehabilitation improved exercise performance and quality of life in both groups. Supplementation of oxygen during the training did not add to the effects of training on room air.

Effects of salbutamol on rat diaphragm contractility

The aim of this study was to investigate 1) the effects and time course of single doses of salbutamol on isometric contractile properties of isolated rat diaphragm strips and 2) whether these effects were caused by a direct effect on the muscle. Two experiments were performed. In one, salbutamol was administered subcutaneously in doses of 12.5, 25, 50, or 100 micrograms/kg (25 and 50 micrograms/kg sc resulted in serum concentrations of approximately 9 and approximately 15 micrograms/l, respectively, 0.5 h after injection) and in vitro contractile properties were determined 0.5, 1, 2, or 4 h after administration; in the other, salbutamol was added to the tissue bath in a concentration of < or = 2, approximately 10, approximately 20, and approximately 80 micrograms/l. Twice force, maximal tetanic force, and twitch force-to-tetanic force ratio all increased in a dose-dependent way in both experiments. The increases in force generation were slightly higher after subcutaneous administration. Force-frequency curves were shifted upward in both experiments. No significant effects of time of salbutamol administration were found, but the increase in force generation was most pronounced within 2 h after subcutaneous administration. In conclusion, in vitro force generation can be improved by low concentrations of salbutamol. The slightly higher increases in force generation after subcutaneous administration suggest that in vivo salbutamol may have additional positive inotropic actions on diaphragm contractility besides a direct beta 2-adrenergic effect on the muscle itself.

Evaluation of the suitability of weekly peak expiratory flow rate measurements in monitoring annual decline in lung function among patients with asthma and chronic bronchitis

BACKGROUND

Early detection and treatment of patients with asthma or chronic bronchitis who have a rapid annual decline in lung function is essential in order to improve their long-term prognosis. This annual rate of decline can be assessed accurately by monitoring the forced expiratory volume in one second (FEV1) which is a routine procedure in hospital respiratory laboratories but not in general practice. General practitioners usually measure patients' peak expiratory flow rate (peak flow) to evaluate lung function. If annual decline in lung function can be assessed by monitoring peak flow, this method could be used in general practice for detecting patients at an early stage who have a rapid decline.

AIM

A study aimed to investigate the long-term correlation between FEV1 and peak flow among a group of patients in Nijmegen, the Netherlands.

METHOD

FEV1 and peak flow were monitored in 53 patients with moderate asthma and 78 patients with moderate chronic bronchitis over four years. FEV1 was measured in a laboratory once every six months and peak flow was measured by patients once a week. The correlation between the two sets of measurements was studied for each patient.

RESULTS

Four-year data for 83 of the 131 patients were analysed; the other 48 patients received inhaled steroids during the second half of the study period so their data were not considered for all the analyses. Of the 83 patients, 35 (42%) showed a decrease in both FEV1 and peak flow. Thirty six patients (43%) showed a decrease in FEV1 and an increase in peak flow. Four patients (5%) showed an increase in FEV1 and a decrease in peak flow and eight patients (10%) showed an increase in both rates. Approximately similar results were seen in a separate analysis of all 131 patients during the first two years of the study.

CONCLUSION

No long-term correlation was found between FEV1 and peak flow. Peak flow is not capable of detecting annual decline in lung function. Therefore it cannot be used to detect patients with asthma or chronic bronchitis who have a rapid annual decline in lung function. Spirometers, which measure peak flow and FEV1, could be used in general practice. These would allow general practitioners to continue measuring peak flow in order to assess short-term changes in lung function while providing an important means for monitoring FEV1 to assess long-term changes in lung function.

Pancreatic morphology and function in adult patients with cystic fibrosis

To determine the relation between pancreatic morphology and pancreatic exocrine and endocrine function, we have studied 8 adult cystic fibrosis patients and 14 normal control subjects by ultrasonography and pancreatic function testing. In the patients with cystic fibrosis the maximum anteroposterior diameter of the pancreatic head was significantly increased over that in control subjects (p less than 0.01), whereas the maximum diameter of the body was significantly decreased (p = 0.05). Increased echogenicity of the pancreatic body was observed in most patients. In the cystic fibrosis patients postprandial insulin secretion was reduced in the 1st h (p less than 0.005 versus control), whereas pancreatic polypeptide secretion was virtually abolished for at least 3 h (p less than 0.01 versus control). All cystic fibrosis patients had evidence of exocrine pancreatic dysfunction as reflected by a diminished urinary para-aminobenzoic acid excretion. Intraduodenal enzyme and bicarbonate output in response to secretin-cholecystokinin was reduced in all of three patients studied. It is concluded that loss of endocrine and exocrine pancreatic function in adult cystic fibrosis patients is accompanied by a small and echo-dense pancreatic body relative to a large pancreatic head.

Interacting effects of atopy and bronchial hyperresponsiveness on the annual decline in lung function and the exacerbation rate in asthma

The relationship between atopy and bronchial hyperresponsiveness (BHR) on the one hand and the annual rate of decline in FEV1 and the annual exacerbation rate on the other was studied in 71 adult patients with asthma during a period of 2 yr. Atopy (based on seven RAST tests) and BHR (PC20-histamine) were assessed at the start of the 2-yr follow-up period, and they were related to the decline in FEV1 (FEV1 slope) and the exacerbation rate. The results indicated that BHR was related to the FEV1 slope independently of the FEV1 level. The mean prebronchodilator FEV1 slope was -94 ml/yr (-39 to -149 ml/yr) in patients with PC20 less than or equal to 2 mg/ml and -21 ml/yr (+34 to -76 ml/yr) in patients with PC20 greater than 2 mg/ml. Atopy alone was not related to the FEV1 slope. However, in atopic patients BHR was related to a more pronounced FEV1 slope than in nonatopic patients. The slope of the postbronchodilator FEV1 was comparable with the slope of the prebronchodilator FEV1, which may indicate that the loss of FEV1 was not only due to increased bronchospasm but also to fixed obstruction. BHR and atopy were not associated with the exacerbation rate. Asthmatic patients with atopy and marked BHR should be looked upon as patients with a risk of developing progressive airflow obstruction.

Psychological changes during pulmonary rehabilitation and target-flow inspiratory muscle training in COPD patients with a ventilatory limitation during exercise

The effects of pulmonary rehabilitation (PR), target-flow inspiratory muscle training (IMT) and a combination of both treatments (PR + IMT) on psychological parameters and the physical performance were studied in a group of sixty chronic obstructive pulmonary disease (COPD) patients with a ventilatory limitation during exercise (mean age +/- 59, mean FEV1 +/- 50% of predicted). After the ten week training period scores of anxiety and depression were decreased in the PR and the PR + IMT group, but not in the IMT group. In the PR group these scores were still decreased after a one year follow up period. Maximal workload and the activities in daily life (ADL) scores were improved significantly after the training period in the PR and the PR + IMT group. Most of these improvements had disappeared after one year. The 12 min walking distance was increased in all patient groups after the training period and was still increased after the follow up period. The exercise capacity was correlated significantly to lung function parameters. The psychological well-being, however, was not correlated with lung function parameters, but was closely related to ADL scores. The improvement of the psychological parameters was not correlated to the improvement of the exercise capacity after the training period or after one year. The results indicate that the psychological well-being and the physical condition are improved by different mechanisms during a pulmonary rehabilitation programme.

Muscarinic receptor sensitivity in airway smooth muscle of patients with obstructive airway disease

The hypothesis of an increased muscarinic receptor sensitivity in airway musculature of patients with asthma, chronic obstructive bronchitis and emphysema was investigated through methacholine-induced contraction of isolated airway smooth muscle strips. Contractile responses were recorded isotonically in tracheal smooth muscle preparations of 5 patients with chronic obstructive bronchitis, 2 patients with emphysema and 1 patient with allergic asthma, as well as in bronchial tissue preparations of 7 patients with chronic obstructive bronchitis. The responses were compared to those obtained in airway tissue preparations of 25 control subjects. The sensitivity to methacholine was normal in all groups of patients. This suggests that muscarinic receptor behaviour is normal in airway smooth muscle of patients with obstructive airway disease.

The effect of the 4-quinolone enoxacin on plasma theophylline concentrations

In patients treated concomitantly with theophylline and enoxacin, a broad spectrum antibacterial agent for oral administration, unexpectedly high plasma theophylline concentrations were observed. In six patients receiving intravenous aminophylline under controlled conditions, enoxacin was started in a daily dose of 800 or 1200 mg. Plasma theophylline concentrations increased from 8.4 +/- 2.4 mg/l to 15.0 +/- 5.1 mg/l at day 3 of co-administration. Total body clearance of theophylline decreased significantly, whereas renal clearance and protein binding did not change. When enoxacin, 800 mg daily, was administered to seven patients with a stable chronic obstructive pulmonary disease, who were on long-term theophylline treatment a significant increase in plasma theophylline concentrations occurred as well: elimination half-life was prolonged. It is concluded that the rise of plasma theophylline concentrations is caused by a reduced metabolic clearance of theophylline. If concomitant use of both drugs is necessary, monitoring of plasma theophylline concentration and adjustment of the theophylline dose is recommended, to avoid toxicity.

Enoxacin decreases the clearance of theophylline in man

In patients treated concurrently with theophylline and enoxacin, a new broad-spectrum antibacterial agent of the quinolone class, unexpectedly high plasma theophylline concentrations were measured. In part I of this study, daily plasma theophylline concentrations were measured in 14 patients. The mean +/- s.d. theophylline concentrations increased from 8.5 +/- 2.8 micrograms ml-1 prior to enoxacin to a maximum of 21.7 +/- 7.8 micrograms ml-1 during coadministration. In part II, six of these patients received aminophylline intravenously at a constant infusion rate and under controlled conditions. Plasma theophylline concentrations rose from 8.4 +/- 2.4 micrograms ml-1 prior to enoxacin treatment to 15.0 +/- 5.1 micrograms ml-1 at day 3 of coadministration (P less than 0.005). Plasma protein-binding and renal clearance of theophylline remained unchanged, whereas total body clearance of theophylline significantly decreased (P less than 0.005). From these observations it is concluded that the rise of plasma theophylline concentrations is caused by a reduced metabolic clearance of theophylline. If concomitant use of both drugs is necessary, monitoring of plasma theophylline concentration and adjustment of the theophylline dose is recommended.

Influence of selective and non-selective beta-adrenoreceptor blockade on the haemodynamic effect of adrenaline during combined antihypertensive drug therapy

1. Haemodynamic effects of adrenaline were studied in 27 hypertensive patients, succesively during treatment with propranol and metoprolol. In 12 patients beta-adrenoreceptor blockade was combined with diuretics and in 15 patients the blockade was combined with vasodilators. 2. During propranolol adrenaline caused a marked pressor effect: there was a considerable rise in systolic as well as in diastolic blood pressure and a marked fall in heart rate. During metoprolol there was only a slight rise in blood pressure and an increase in heart rate. 3. Forearm blood flow was decreased by adrenaline during propranolol and was increased during metoprolol. Calculated vascular resistance showed opposite changes. 4. Results were essentially the same when beta-adrenoreceptor blockade was combined with diuretics or with vasodilators and did not differ from previous results obtained in patients treated by blockade alone. 5. If adrenaline infusion can be considered as a model for acute stress, our results seem to favour a selective beta 1-adrenoreceptor blocking agent over a non-selective one, even when the blocker is combined with a diuretic or a vasodilator.