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Biomedical subjects

Leslie Hendeles

Publications and source records attributed to Leslie Hendeles.

15 recordsLinked to original sources
PubMed2005

Automatic replacement of albuterol nebulizer therapy by metered-dose inhaler and valved holding chamber.

PURPOSE: Evidence supporting the delivery of bronchodilators with a metered-dose inhaler and a valved holding chamber (MDI+VHC) in place of a small-volume nebulizer (SVN) is discussed, and the steps taken to accomplish such a conversion program at one institution are described. SUMMARY: Double-blind, randomized studies in patients with acute exacerbations of asthma have demonstrated that higher doses of albuterol delivered by MDI+VHC (4-10 puffs per dose) are as effective as 2.5 mg of albuterol sulfate delivered by SVN. Three double-blind studies support the conclusion that the two methods are equivalent with respect to both efficacy and adverse effects in patients with chronic obstructive pulmonary disease. MDI+VHC offers practical advantages over SVN, including the capacity for home use by the patient, portability, less setup time, and no need for daily disinfection. Pharmacists and respiratory therapists obtained approval through the pharmacy and therapeutics committee for respiratory therapists to convert orders for bronchodilators delivered by SVN to administration by MDI+VHC. The conversion policy allows physicians to override it, but none have exercised this option. On intensive care units (ICUs), the policy resulted in a 53% increase in the use of MDI+VHC during the six-month period after it went into effect. Respiratory therapists have been less thorough in implementing the policy for non-ICU patients. CONCLUSION: Delivery of bronchodilators by MDI+VHC is as effective as delivery by SVN but offers several advantages. A policy to switch patients from SVN to MDI+VHC for bronchodilator administration met with limited success.

Adult↗
PubMed2004

Response to inhaled albuterol during nocturnal asthma.

BACKGROUND: During conventional daytime studies of beta(2)-agonists, 1 puff of a metered-dose inhaler often produces a near maximum bronchodilator response. Consequently, the US Food and Drug Administration-approved dose of albuterol is only 1 to 2 puffs every 4 to 6 hours. OBJECTIVE: To determine whether a higher dose of albuterol is required to normalize lung function during nocturnal asthma. METHODS: Fifteen subjects (age, 18-37 years) were treated with albuterol metered-dose inhalers in a randomized crossover manner at the onset of nocturnal symptoms while sleeping in the Clinical Research Center and during the day when they were asymptomatic. The dose was doubled at 15-minute intervals to 16 cumulative puffs. RESULTS: The mean +/- SD predose FEV(1) was lower at night than during the day (44% +/- 12% vs 68% +/- 9% predicted; P=.0001). The maximum FEV(1) achieved was also lower at night (84% +/- 15% vs 90% +/- 12%; P=.02). The nocturnal dose-response curve was shifted to the right. The median (25th, 75th percentiles) dose required to achieve 80% of the subject's personal best FEV(1) was substantially higher at night (5 [1, 19] vs 0.4 [<0.25, 2] puffs; P=.02), and the median time to achieve this endpoint was longer (47 [21, 90] vs 10 [0.2, 42] minutes; P=.005). No significant systemic effects were observed. CONCLUSION: At night, the response was slower and required a higher dose because more severe airway obstruction was present on awakening. These results suggest that studies establishing the clinical dose of a beta(2)-agonist or assessing the equivalence of different formulations should be conducted in subjects with more severe reversible airway obstruction than is present during conventional daytime studies.

Administration, Inhalation↗
PubMed2004

Evaluation of cytokine modulators for asthma.

Th2 cytokines play an important role in producing and maintaining airway inflammation in asthma. As a consequence, there is considerable interest in developing agents that modulate their effects. Therapeutic strategies include decreasing cytokine synthesis or release, blocking their effects by antibodies or soluble receptors, as well as administration of anti-inflammatory cytokines. Initial studies of three of these approaches have shown interesting results. The first is suplatast tosilate, a selective Th2-inhibitor that suppresses the synthesis of IL-4 and IL-5 in vitro. In a randomised double-blind placebo-controlled parallel study, suplatast, given orally TID, improved lung function and symptom control when added to inhaled beclomethasone for 4 weeks and prevented deterioration when the beclomethasone dose was decreased by 50% during a second 4 weeks. The second is CDP840, a second generation phosphodiesterase type 4 inhibitor, that may decrease the release of cytokines from eosinophils and Th2 lymphocytes. In a double-blind placebo-controlled crossover study, CDP840, given orally BID for 9 days, attenuated the late response to allergen by 30% when compared to placebo. The third is a recombinant human soluble IL-4 receptor (altrakincept) that neutralises endogenously produced IL-4. In inhaled steroid-dependent subjects, weekly nebulisation of altrakincept prevented lung function decline and asthma exacerbations after abrupt withdrawal of inhaled corticosteroids. In contrast, studies of anti-IL-5 monoclonal antibodies (mepolizumab and SCH55700) indicate that this strategy only partially depletes eosinophils from the bronchial mucosa and shows no benefit on clinical markers of asthma activity. Of these novel therapeutic approaches, inhibiting Th2 synthesis of IL-4 and IL-5 (suplatast) appears to offer the greatest potential and long-term studies of this approach should be undertaken.

Asthma↗
PubMed2004

Methacholine challenge testing: comparison of the two American Thoracic Society-recommended methods.

STUDY OBJECTIVES: Recent American Thoracic Society guidelines recommend two different methods of methacholine challenge testing: the 2-min tidal breathing method with twofold increases in concentration, and the five-breath dosimeter method with fourfold increases. Since the tidal breathing method delivers more methacholine to the mouthpiece, we hypothesized that the provocative concentration of methacholine required to decrease FEV(1) by 20% (PC(20)) would be lower than with the dosimeter method. DESIGN: Twelve subjects 18 to 45 years old with stable asthma were selected on the basis of a screening PC(20) (by tidal breathing) of < 1 mg/mL, 1 to 4 mg/mL, or 4 to 16 mg/mL (4 subjects in each concentration range). On subsequent visits within a 7-day period, methacholine challenge testing with tidal breathing or dosimeter were performed on separate days, in a randomized crossover manner. RESULTS: The geometric mean PC(20) was 1.8 mg/mL (95% confidence interval [CI], 0.7 to 4.3) after tidal breathing and 1.6 mg/mL (95% CI, 0.7 to 3.7) after dosimeter (p = 0.2). There was no significant difference between the screening PC(20) and the PC(20) obtained by either method on randomized study days. The maximum decrease in FEV(1) from diluent baseline after the last concentration was 27.8% (range, 20 to 50%) during tidal breathing and 27.9% (range, 16 to 47%) during the dosimeter method (p = 0.35). CONCLUSIONS: Both methods give similar results. Fourfold increases in methacholine concentration with the dosimeter method are as safe as twofold increases with the tidal breathing method.

Administration, Inhalation↗
PubMed2003

Levalbuterol.

Explore the source record for details and available documents.

Adrenergic beta-Agonists↗
PubMed2003

Are inhaled corticosteroids effective for acute exacerbations of asthma in children?

If started early and at high doses, the acute use of inhaled corticosteroids (ICS) provides modest benefit in patients with mild exacerbations of asthma. In more severe exacerbations, oral corticosteroids are significantly more effective in preventing hospitalizations and improving lung function. We conclude that ICS should not be used routinely to treat acute exacerbations.

Acute Disease↗
PubMed2003

Selecting a systemic corticosteroid for acute asthma in young children.

Oral corticosteroids are as effective as intravenous therapy for treating acute exacerbations of asthma. They are available in tablets that can be crushed and mixed with soft food or syrup, and in a variety of liquid formulations that differ in volume required, palatability, patient acceptance, and cost. The most important consideration in product selection for a young child is that the doses can be easily swallowed and retained.

Acute Disease↗
PubMed2002

Efficacy of calcium channel blockers as maintenance therapy for asthma.

AIMS: Previous bronchoprovocation studies indicate that nifedipine attenuates airway responsiveness to several stimuli whereas diltiazem has no effect. The aim of this study was to determine whether such studies predict the efficacy of calcium channel blockers as maintenance therapy for persistent asthma. METHODS: Twenty-one otherwise healthy adults with persistent asthma, mean age 25 years, completed treatment with maximum tolerated doses of placebo (P), nifedipine (N), and diltiazem (D) in a double-blind, randomized, three-treatment, three-period, crossover manner, each for 4 weeks. Frequency and severity of asthmatic symptoms were recorded twice daily, as well as peak expiratory flow and frequency of 'prn' use of inhaled terbutaline. Blood pressure, heart rate, P-R interval of the ECG and spirometry were measured biweekly. At the end of each treatment, airway responsiveness to exercise was measured. RESULTS: The mean (s.e. mean)% of days with wheeze was 69plus minus7% during P, 75plus minus6% during N and 72plus minus6% during D (P=0.7). FEV1 was 79plus minus2% of predicted during P, 81plus minus2% during N and 79plus minus2% during D (P=0.6). The decrease in FEV1 after exercise was 32plus minus4% during P, 32plus minus5% during N and 27plus minus4% during D (P=0.5). Heart rate was elevated during N (P=0.0002) whereas P-R interval was prolonged during D (P=0.0001). CONCLUSIONS: Maintenance therapy with calcium channel blockers, at doses that produce cardiovascular effects, do not suppress the signs and symptoms of persistent asthma. Previous bronchoprovocation studies did not predict these results.

Adolescent↗
PubMed2002

Asthma therapies and Churg-Strauss syndrome.

The pulmonary vasculitides are a group of rare but serious disorders that require early recognition, accurate diagnosis, and effective therapy. Churg-Strauss syndrome (CSS) is classified as small vessel vasculitis. Four different definitions for the diagnosis of CSS have been developed: (1) the pathologic criteria put forth by Churg and Strauss, (2) the criteria based on clinical grounds from Lanham and colleagues, (3) the criteria based on clinical grounds from the American College of Rheumatology, and (4) the criteria from the Chapel Hill Consensus Conference, which closely concur with the Churg and Strauss definition. It is apparent that cessation, diminution, or even a switch from low-dose systemic to inhaled corticosteroid therapy can precipitate the appearance of CSS. The term forme fruste has been used to indicate that the signs and symptoms of CSS were (inadvertently) suppressed by cortico-steroids. The clinical risk factors for CSS are moderately severe or severe asthma, chronic sinusitis, or reductions in systemic corticosteroid therapy. Differential diagnosis, treatment, and ongoing monitoring of CSS therapeutic responses are reviewed. The introduction of leukotriene modifiers and high-potency inhaled corticosteroids have allowed control of asthma symptoms, which results in avoidance or reduction in oral corticosteroid use. The advent of these agents has been associated with reports of CSS appearing in patients with asthma. The available data regarding the association of CSS and antiasthma agents are most consistent with the unmasking of a previously contained pathologic condition (forme-fruste CSS) or disease that progresses because systemic corticosteroids were avoided. Early recognition and immunosuppressive therapy are the keystones of successful treatment of this rare disorder.

Adrenal Cortex Hormones↗
PubMed2002

Accuracy of three electronic monitors for metered-dose inhalers.

BACKGROUND: Prior studies indicate that some devices used to monitor metered-dose inhaler (MDI) use are not accurate. OBJECTIVE: To assess the accuracy of the Doser CT (NEW-MED Corporation; Waltham, MA), the MDILog (Medtrac Technologies; Lakewood, CO), and the SmartMist (Aradigm Corporation; Hayward, CA) in a bench-top study. DESIGN: One, two, and four puffs of fluticasone propionate MDI (Flovent; GlaxoWellcome; Research Triangle Park, NC) were actuated twice daily for 30 days with two units of each device. The date and time of each actuation were recorded in a log and then compared with the output of the device. The percentage of doses recorded accurately was compared by analysis of variance. MEASUREMENTS AND RESULTS: The SmartMist was 100% accurate, while both the Doser CT and MDILog devices occasionally recorded spurious actuations. The Doser CT also had missed actuations after the counter had prematurely reached zero secondary to the spurious recordings. The accuracy (mean plus minus SD) was 94.3 plus minus 2.9% for the Doser CT and 90.1 plus minus 6.9% for the MDILog (p = 0.21). The dose regimen actuated and duration of use did not significantly affect accuracy. CONCLUSION: All three devices are sufficiently accurate to monitor adherence in most clinical settings.

Androstadienes↗
PubMed2002

Stability of frozen methacholine solutions in unit-dose syringes for bronchoprovocation.

OBJECTIVE: Methacholine solutions < 0.25 mg/mL must be prepared fresh daily, while concentrations > or = 0.25 mg/mL must be prepared at 2-week intervals according to US Food and Drug Administration-required labeling. The purpose of this report was to determine whether freezing methacholine solutions in unit-dose syringes would allow less frequent preparation. DESIGN: Diluent containing 0.5% sodium chloride, 0.275% sodium bicarbonate, and 0.4% phenol was used to prepare 11 concentrations of methacholine ranging from 0.031 to 32.0 mg/mL. Three milliliters of each dilution was placed into 5-mL polypropylene syringes and immediately frozen. Methacholine concentrations were determined using a validated high-performance liquid chromatography assay after preparation (time zero) and at 0.5, 1, 1.5, 2, 3, 4, 5, and 6 months. On the day of analysis, the samples were allowed to thaw to room temperature. An additional set of each dilution was stored at room temperature for 24 h after thawing and then analyzed for methacholine. RESULTS: Samples > or = 0.062 mg/mL analyzed immediately after thawing retained > or = 90% of labeled potency for at least 6 months, while the 0.031-mg/mL sample retained 90% potency for 4 months. Most samples analyzed 24 h after thawing lost potency. CONCLUSION: If prepared and stored in unit-dose syringes frozen, methacholine solutions containing 0.062 to 32.0 mg/mL can be prepared at 6-month intervals, and solutions containing 0.031 mg/mL can be prepared at 4-month intervals. Once thawed, unused methacholine solutions should be discarded.

Bronchial Provocation Tests↗
PubMed2002

Differences in inhaled fluticasone bioavailability between holding chambers in children with asthma.

STUDY OBJECTIVE: To determine if differences between holding chambers in previous in vitro aerosol studies would agree with the bioavailability of inhaled fluticasone propionate between the same holding chambers in children with asthma. DESIGN: Double-blind, randomized, crossover study SETTING: University of Florida Clinical Research Center. PATIENTS: Eight children (aged 5-9 yrs) with stable asthma. INTERVENTION: Under observation, the children inhaled two 110-microg puffs of fluticasone twice/day through the InspirEase or E-Z Spacer holding chamber. MEASUREMENTS AND MAIN RESULTS: Blood samples were collected at baseline and then at 0.5, 1, 1.5, 2, 4, and 6 hours after the last dose of fluticasone. Primary outcome measures were peak fluticasone steady-state plasma concentration (Cmax) and area under the fluticasone plasma concentration-time curve from 0-6 hours (AUC0-6). The fluticasone plasma concentrations were determined by high-performance liquid chromatography-mass spectrometric assay. Mean +/- SD Cmax from InspirEase (245 +/- 77 pg/ml) was 18% higher than that after E-Z Spacer (199 +/- 58 pg/ml, p < 0.05). Mean +/- SD AUC0-6 from InspirEase (1103 +/- 305 pg x hr(-1) x ml(-1) was 22% higher than that delivered from E-Z Spacer (863 +/- 258 pg x hr(-1) x ml(-1), p = 0.06). CONCLUSION: Differences in inhaled fluticasone bioavailability between these holding chambers in children with asthma corroborate differences reported in earlier in vitro aerosol studies.

Administration, Inhalation↗