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PubMed1995

Do inhaled steroids have similar efficacy? A case of bronchial asthma suggesting different efficacy of inhaled glucocorticosteroids.

We report a 35-year-old woman who had had bronchial asthma for 17 years. Her asthma worsened and became unstable on treatment with beclomethasone dipropionate (BDP), budesonide (BUD), and oral glucocorticosteroids (GC). At the age of 31, she had participated in a clinical trial with fluticasone propionate (FP), and after 2 weeks' treatment her asthma was well controlled. Because of pregnancy, her participation was terminated and treatment continued with available inhaled GC; however, the disease deteriorated and treatment with FP was resumed 2 years ago. Lung function normalized after 3 weeks and she has remained clinically stable since.

Administration, Inhalation↗
PubMed2005

Comparison of inhaled corticosteroid combined with theophylline and double-dose inhaled corticosteroid in moderate to severe asthma.

OBJECTIVE: Recent studies have found that theophylline exerts anti-inflammatory and immunomodulatory effects. This study was performed to compare the efficacy of inhaled corticosteroids (ICS) combined with slow-release theophylline (SRT) with that of double-dose ICS in asthma control, anti-inflammatory activity and safety. METHODOLOGY: In a randomized, open, parallel, control trial, 41 patients with asthma were randomly treated with either beclomethasone dipropionate 500 microg b.i.d. (BDP group) or a combination of BDP 250 microg b.i.d and SRT 0.2 g b.i.d. (SRT/BDP group) for 6 weeks. At the start and at the end of treatment, lung function testing and sputum induction were performed, and plasma cortisol levels were measured. Sputum was analyzed for cell differential counts and the interleukin (IL)-5 level. Patients kept a record of peak expiratory flow (PEF), symptom score, and beta2-agonist use. RESULTS: Significant increases in the morning and the evening PEF and FEV1 were observed (P < 0.05), together with an obvious reduction in symptom score and beta2-agonist use (P < 0.01). Significant decreases in the percentage eosinophils and IL-5 level in induced sputum also occurred (P < 0.05). However, there was no difference between the two groups for all these parameters. There was no significant change in the plasma cortisol level for either group. CONCLUSIONS: Both ICS combined with SRT and double-dose ICS had the same effect on asthma control, improving symptoms and ameliorating lung function. Both therapies had similar anti-airway inflammatory effects and therapeutic safety. Combining SRT with ICS may allow a reduction in ICS dose when treating asthma.

Administration, Inhalation↗
PubMed2005

Moderate dose inhaled corticosteroids plus salmeterol versus higher doses of inhaled corticosteroids in symptomatic asthma.

BACKGROUND: There is uncertainty as to the dose of inhaled corticosteroids (ICS) at which to start concomitant long acting beta agonist (LABA) treatment in patients with asthma not adequately controlled by ICS alone. METHODS: A meta-analysis was carried out of randomised, double blind clinical trials that compared the efficacy of adding salmeterol to moderate doses of ICS (fluticasone propionate 200 mug/day or equivalent) with increasing the ICS dose by at least twofold in symptomatic adult patients with asthma. The main outcome measures were the number of subjects withdrawn from the study due to asthma and the number of subjects with at least one moderate or severe exacerbation. RESULTS: Twelve studies with a total of 4576 subjects met the inclusion criteria for the analyses. The number of subjects withdrawn due to asthma and with at least one moderate or severe exacerbation was higher in the high dose ICS group (odds ratios 1.58, 95% CI 1.12 to 2.24 and 1.35, 95% CI 1.10 to 1.66, respectively). For the secondary outcome variables (forced expiratory volume in 1 second, morning and evening peak expiratory flow, and daytime beta agonist use) there was significantly greater benefit in the salmeterol group. CONCLUSIONS: This meta-analysis shows that the addition of salmeterol to moderate doses of ICS (fluticasone 200 mug/day or equivalent) in patients with asthma symptomatic at that dose results in significantly greater clinical benefit than increasing the dose of ICS by twofold or more.

Administration, Inhalation↗
PubMed2005

Neonatal Ventilation With Inhaled Nitric Oxide Versus Ventilatory Support Without Inhaled Nitric Oxide for Preterm Infants With Severe Respiratory Failure: the INNOVO multicentre randomised controlled trial (ISRCTN 17821339).

BACKGROUND: Although inhaled nitric oxide (iNO) may be a promising treatment for newborn infants with severe respiratory failure, the results from 3 previous small trials were inconclusive. METHODS: Infants of <34 weeks' gestation, <28 days old, and with severe respiratory failure requiring ventilatory support were randomized to receive or not receive iNO. The study was not blinded. FINDINGS: Recruited were 108 infants (55 allocated to receive iNO and 53 not allocated to receive iNO) from 15 neonatal units in the United Kingdom and Republic of Ireland. Fifty-nine percent (64 of 108) died, and 84% of the survivors (37 of 44) had signs of some impairment or disability, 9 (20%) of them classified as severely disabled. There was no evidence of an effect of iNO on the primary outcomes: death or severe disability at 1 year corrected age (relative risk [RR]: 0.99; 95% confidence interval [CI]: 0.76 to 1.29); death or supplemental oxygen on expected date of delivery (RR: 0.84; 95% CI: 0.68 to 1.02); or death or supplemental oxygen at 36 weeks' postmenstrual age (RR: 0.98; 95% CI: 0.87 to 1.12). There was a trend for infants allocated to the iNO group to spend more time on the ventilator (log rank: 3.6), on supplemental oxygen (log rank: 1.4), and in hospital (log rank: 3.5) than those allocated to receive no iNO. This pattern predominantly reflected the infants who died. Mean total costs at 1 year corrected age were significantly higher in the iNO group, partly because of the costs of the gas but mainly because of the difference in initial hospitalization costs. INTERPRETATION: Evidence of prolongation of intensive care and increased costs of such care, without clear beneficial effects, implies that iNO cannot be recommended for preterm infants with severe hypoxic respiratory failure.

Administration, Inhalation↗
PubMed1992

Recommendations for the conduct of acute inhalation limit tests. Prepared by The Technical Committee of the Inhalation Specialty Section, Society of Toxicology.

This paper reviews the scientific issues related to exposure concentrations and particle sizes used in acute inhalation limit tests. The current United States Environmental Protection Agency (USEPA) recommended exposure concentration for such tests is 5 mg/liter; while this level is very high, it is often achievable. On the other hand, its toxicological relevance is questionable. The USEPA recommendation that 25% of the particle distribution be less than 1 micron is a more difficult issue to address. Physical laws for aerosol particle generation and behavior limit the minimum size of particles in an exposure atmosphere at a concentration of 5 mg/liter. Particle size also influences deposition site in the respiratory tract. Since damage to any region of the respiratory tract can produce lethality, and it is not possible to predict, a priori, the most responsive region of the tract or the most harmful particle size of an untested agent, acute limit testing should employ particles in a size range that deposits throughout the entire rodent respiratory tract. Particles between 1 and 4 microns mass median aerodynamic diameter (MMAD) are well suited for such studies. It is, therefore, recommended that the limit test concentration should be the highest concentration (up to 5 mg/liter) that can be achieved while still maintaining a particle size distribution having an MMAD between 1 and 4 microns.

Administration, Inhalation↗
PubMed1997

Retardation of the age-related increase in spontaneous cortical spike-wave discharges (SWD) in rats after a 28-day inhalation (SWD) in rats after a 28-day inhalation exposure to an industrial solvent, pseudocumene (1,2,4-trimethylbenzene).

It has been hypothesized that exposure to neurotoxins may hasten the process of brain ageing. Volatile hydrocarbons are in common use as solvents and their neurotoxic properties are acknowledged. In the rat, the age-related neurodegenerative changes in the brain develop together with an increased occurrence of bursts of spontaneous spike-wave discharges (SWD) in the neocortex. Therefore, the number and/or duration of SWD bursts may serve as an index allowing to distinguish between young and old brains (7). Measuring the SWD activity after exposure may thus reveal the effect of the studied neurotoxicant on brain ageing. Pseudocumene (1,2,4-trimethylbenzene, TMB), is a component of industrial solvent mixtures. The present study investigated the effect of a 4-week (6h/day, 5 days/week) inhalation exposure to TMB at concentrations of 0, 25, 100 or 250 ppm on the occurrence of SWD bursts. EEG recordings were performed before and one day, 30 days and 4 months after exposure. In rats exposed to TMB at 0 and 25 ppm, the level of the SWD activity increased progressively after exposure. In rats exposed to TMB at 100 or 250 ppm, the SWD activity did not increase during the post-exposure period or even dropped below the pre-exposure level. This result indicates that the persistent changes in the rat central nervous system (CNS), following the exposure to TMB, differ in some respects from those which develop in the course of normal ageing.

Administration, Inhalation↗
PubMed1976

A study of inhalation of pentachlorophenol by rats. IV. Distribution and excretion of inhaled pentachlorophenol.

It appears that in the rat repeated respiratory exposures to PCP do not result in an increase in the body burden of this compound as would be suspected from the 24 hour half-life determined from a single inhalation exposure. These results suggest some mechanism induced by prior exposure to PCP that increases the ability of the animals to remove this compound from its body. Increased excretion may be a factor in this activity, however, it cannot account for the total effect. Storage appears unlikely, since the elimination rate and time period remain unchanged after five doses as compared to after one. Increased matebolism may be the explanation, although this mechanism can only be inferred from these data. Quantitative metabolic results will be necessary to support this hypothesis.

Aerosols↗
PubMed2001

Effects of inhalation of perfluorocarbon aerosol on oxygenation and pulmonary function compared to PGI2 inhalation in a sheep model of oleic acid-induced lung injury.

OBJECTIVE: To evaluate the effects of PFC aerosol compared to PGI2 aerosol and NaCl aerosol on gas exchange and lung mechanics in oleic acid-induced acute lung injury. DESIGN: A prospective, controlled, randomised, in vivo animal laboratory study. SETTING: Research laboratory at an university hospital. SUBJECTS: Twenty one (n = 21) adult sheep of either gender weighing 26.8+/-6.4 kg. INTERVENTIONS: The animals were randomised to three groups: PFC aerosol (perfluorooctane), PFC group; prostacyclin aerosol (Flolan), PGI2 group; and NaCl aerosol (0.9% sodium chloride solution), control group. After induction of anaesthesia and placement of vascular catheters, lung injury was induced with 0.12 ml x kg(-1) oleic acid. Aerosols were continuously administered for 2 h using a jet nebuliser. Gas exchange, pulmonary mechanic, and haemodynamic parameters were obtained at regular intervals. MEASUREMENTS AND MAIN RESULTS: PFC aerosol increased oxygenation (PaO2) 15 min after the initiation of treatment up to 120 min (P < 0.05). Transpulmonary shunt improved in the PFC group (P < 0.05) while it did not change in the two other groups. PFC aerosol reduced maximum airway pressure (Pmax) (median) significantly from (median) 38 mbar to 32 mbar (P < 0.05). Static compliance improved significantly in the PFC group (P < 0.05). CONCLUSION: The inhalation of a PFC aerosol led to a significant improvement in pulmonary mechanics and gas exchange, which was not observed in the other two groups. These data suggest that a small dose of perfluorocarbon will have beneficial effects on gas exchange and respiratory mechanics. Therefore, the non-invasive aerosol application technique seems to be a reasonable alternative to administer perfluorocarbons in severe lung injury.

Aerosols↗
PubMed1983

Influence of elastase-induced emphysema and the inhalation of an irritant aerosol on deposition and retention of an inhaled insoluble aerosol in Fischer-344 rats.

The purpose of this study was to assess the effects of elastase-induced pulmonary emphysema and the inhalation of an irritant aerosol (Triton X-100, a nonionic surfactant similar to those used in a number of pressurized consumer products) on pulmonary deposition and retention of an insoluble test aerosol, 59Fe-labeled Fe2O3. Untreated rats or rats pretreated by intratracheal instillation with elastase were exposed to an aerosol of 59Fe-labeled Fe2O3 either 18 hr or 7 days after exposure to aerosolized Triton X-100 which was administered in doses of 20, 100, or 200 micrograms/g of lung. Rats pretreated with elastase had significantly lower pulmonary deposition of 59Fe than the untreated controls (p less than 0.005). Pulmonary deposition of Fe2O3 was unaffected by pretreatment with Triton X-100. Elastase treatment alone had no effect on retention of Fe2O3. Triton X-100 administered 18 hr prior to exposure of rats to Fe2O3 aerosol resulted in dose-related increases in whole-body retention of 59Fe. When rats were exposed to Triton X-100 7 days before exposure to Fe2O3, increased retention of 59Fe was noted only in those treated at the highest Triton X-100 dose level (200 micrograms/g).

Aerosols↗
PubMedDate not supplied

Inhalation toxicity studies on cigarette smoke II. Tobacco smoke inhalation dosimetry studies on small laboratory animals.

A newly developed exposure system has been used to carry out smoke dosimetry studies on rats, mice, hamsters and guinea pigs. In all species, smoke total particulate matter (TPM) deposited in significant amounts in the lower respiratory system (LRS) at dose levels ranging from 0.515 to 1.710 mg TPM/g respiratory tissue. Nasal deposition of smoke particulates did occur in all of the species examined. The significance of these dosimetry data in relation to the conduct of long-term comparative inhalation toxicity studies with tobacco smoke is discussed.

Air↗
PubMedDate not supplied

Inhalation toxicity studies on cigarette smoke III. Tobacco smoke inhalation dosimetry study on rats.

Smoke inhalation dosimetry studies have been carried out on rats, using a new exposure system. A range of cigarettes, tobacco types and smoke concentrations was used. Penetration of smoke into the lungs was clearly demonstrated, and loads of total particulate matter (TPM) of up 1 mg were detected in the lower respiratory system of rats. The mass of TPM deposited was affected by the smoke concentration during exposure. Deposition of TPM in the head of the rat was low in relation to total respiratory system deposition. A pattern of predominantly lung deposition was achieved under the conditions used for this series of experiments. This pattern was not affected by changes in smoke dilution level, cigarette or tobacco type.

Animals↗
PubMed1990

Optimized inhalation aerosols. II. Inertial testing methods for particle size analysis of pressurized inhalers.

Pressurized metered dose inhaler (MDI) output from three different albuterol formulations was characterized using three inertial separation devices. Results were compared for the Delron six-stage cascade impactor (DC16), the Andersen Mark II eight-stage impactor (AC18), and Copley's twin-stage liquid impinger (LI). None of the devices tested in this study was ideal in all respects. All devices could differentiate between formulations in terms of respirable doses (albuterol amount with aerodynamic diameters less than 5.5 through 6.4 microns). Only the high-flow rate LI could differentiate among all three formulations when data were presented in terms of respirable percentage (RP) of drug collected. Values for RP were in excellent agreement for the independently calibrated impactors when the same evaporation chamber was used atop the impactors. The LI appeared to overestimate values for RP in vivo. Results are discussed in light of the debate surrounding the revision of USP aerosol testing requirements. Rigorous specifications for evaporation chambers and methodologies are necessary for meaningful inter- and intra-laboratory comparison of results when any of these devices are used.

Aerosols↗
PubMed1984

Measurement of cerebral blood flow using bolus inhalation of C15O2 and positron emission tomography: description of the method and its comparison with the C15O2 continuous inhalation method.

This article describes a rapid method for the regional measurement of cerebral blood flow using a single breath of C15O2 and positron emission tomography. The technique is based on the bolus distribution principle and utilises a reference table for the calculation of flow. Seven subjects were studied using both this method and the C15O2 continuous inhalation steady-state technique. The single-breath method gave flow values 20% higher than those obtained using the steady-state method. A simulation study was performed in an attempt to define the reasons for the difference between the two techniques. Estimations were made of identified sources of error in the measurement of regional cerebral blood flow using the single-breath technique and compared with results from a similar study previously described for the steady-state technique. However, further comparative studies will be necessary to satisfactorily explain the difference between both techniques.

Adult↗
PubMed1975

Inhalation carcinogenicity of alpha halo ethers. I. The acute inhalation toxicity of chloromethyl methyl ether and bis(chloromethyl)ether.

A range of acute studies were performed with chloromethyl methyl either (CMME) and bis(chloromethyl)ether (BCME), including 14-day LC50's following single seven-hour inhalation exposures. The LC50's for CMME were 55 ppm for rats and 65 ppm for hamsters. The LC50's for BCME were 7 ppm for both species. All animals showed characteristic changes of acute irritation of the respiratory tract manifested by congestion, edema, and hemorrhage. Severe shortening of life span was seen in 30-day exposures of rats to CMME and in all studies with BCME. Incidences of mucosal changes, including atypia, were generally increased in a dose-related manner in both species. The carcinogenicity of BCME in these range finding experiments was demonstrated by a skin cancer in a rat after three exposures and a nasal tumor in a hamster after one exposure to 1 ppm BCME.

Animals↗
PubMed1985

Hemodynamic effects of inhaled ipratropium bromide, alone and combined with an inhaled beta 2-agonist.

Inhaled ipratropium bromide's reported lack of cardiovascular side effects has led to recommendations for its use as a bronchodilator in patients with coexisting cardiovascular disease and in combination regimens with adrenergic agents. To assess the hemodynamic effects of ipratropium, we monitored 10 volunteers by M-mode echocardiography following metered-dose ipratropium administered alone and with fenoterol. On 2 separate days, subjects were monitored for 90 min as they received either 160 micrograms of ipratropium or placebo in divided doses plus 400 micrograms of fenoterol at time 60 min. Following ipratropium alone, heart rate (HR) decreased 3 beats/min, a small but significant difference from placebo (p less than 0.04). Stroke volume (SV) and ejection fraction rose significantly (3 ml and 2%, respectively; p = 0.05) so that cardiac output (CO) was unchanged. By contrast, fenoterol alone (following placebo) produced marked increases in HR (13 beats/min), SV (14 ml), and CO (44%), with a marked fall in total peripheral vascular resistance (29%). Ipratropium administered before and with fenoterol had minimal additive effect. Although SV was slightly higher with the combination of drugs than with fenoterol alone (100.1 ml versus 93 ml; p = 0.05), CO was not significantly greater (6.9 L/min versus 6.4 L/min; p greater than 0.10). We conclude that metered-dose ipratropium alone has small and clinically unimportant hemodynamic effects and produces no clinically significant increases in the cardiovascular side effects of the bronchodilator regimen when given with fenoterol.

Adrenergic beta-Agonists↗
PubMed1993

Nurses' performance of inhalation technique with metered-dose inhaler plus spacer device.

OBJECTIVE: To determine if nurses could correctly use a metered-dose inhaler plus spacer (MDI-spacer) device after a brief description and demonstration of proper use by a clinical pharmacist. DESIGN: Pretest, educational intervention, posttest. SETTING: University hospital. PARTICIPANTS: Twenty-three nurses. INTERVENTIONS: Nurses were asked to use the MDI-spacer (Aerochamber) and were scored using a nine-point checklist (pretest). Educational intervention by the clinical pharmacist consisted of a five-minute discussion and correct demonstration of the device. Nurses were then asked to use the device again (posttest). MAIN OUTCOME MEASURES: Pre- and posttest scores. RESULTS: Total scores were improved after the educational intervention (66 percent pretest vs. 88 percent posttest, p = 0.0001). In an item analysis, four of the nine steps had improved significantly. CONCLUSIONS: A brief discussion and demonstration of correct use of MDI-spacers is effective in improving nurses' skill in using the device.

Clinical Competence↗