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Objective: A few studies report comparable analgesic efficacy between low-dose ketamine and opioids such as morphine or fentanyl; however, limited research has explored the safety and effectiveness of intravenous low-dose ketamine as a primary analgesic in a civilian prehospital setting. The objective of this study is to compare pain control between low-dose ketamine and fentanyl when administered intravenously (IV) for the indication of severe pain. Methods: This was a retrospective, observational review of prehospital adult patients (≥18 years) who presented with severe pain (numeric rating scale, 7-10) and were treated solely with either low-dose ketamine IV or fentanyl IV between January 1, 2014 and December 31, 2016. Propensity matched analysis was performed adjusting for all baseline variables with p ≤ 0.10 and for baseline pain score to match ketamine and fentanyl patients on a one-to-one ratio. The primary outcome was change in pain score from baseline to after treatment and evaluated with a paired t-test. Secondary outcomes were changes in vital signs and Glasgow coma scale (GCS) from baseline to after treatment, as well as incidence of clinically significant adverse events (AEs); AEs were followed from scene arrival through emergency department discharge. Results: Propensity matched analysis produced 79 matched pairs. Ketamine IV patients, receiving a mean (SD) dose of 0.3 (0.1) mg/kg, showed a significantly larger mean decrease in pain after treatment, compared to the fentanyl IV patients (−5.5 (3.1) vs. −2.5 (2.4), p < 0.001). A significantly greater proportion of patients receiving ketamine IV achieved at least a 50% reduction in pain compared to those receiving fentanyl IV (67% vs. 19%, p < 0.001), marking 52 ketamine IV patients as responders to treatment. Vital signs demonstrated a nonsignificant decrease in blood pressure, respiratory rate, heart rate, and GCS. No clinically significant AEs were reported for patients receiving ketamine IV. Conclusion: The significant reduction in pain, significantly high proportion of ketamine responders, and the lack of clinically significant AEs characterizing patients receiving low-dose ketamine IV compared to fentanyl IV, all provide further support for its use as an effective prehospital analgesic. Level of Evidence: Level III, therapeutic. [ABSTRACT FROM AUTHOR]

Background: Montelukast, an oral, once-daily leukotriene receptor antagonist, provides protection against exercise-induced bronchoconstriction.Objective: To evaluate the effect of 8 weeks of therapy with salmeterol aerosol or montelukast on exercise-induced bronchoconstriction in adults with asthma.Design: 8-week multicenter, randomized, double-blind study.Setting: 17 asthma treatment centers in the United States.Patients: 191 adults with asthma who had documented exercise-induced bronchoconstriction.Intervention: Qualified patients were randomly assigned to double-blind treatment with montelukast (10 mg once in the evening) or salmeterol (50 microg [2 puffs] twice daily).Measurements: Changes in pre-exercise and postexercise challenge values; percentage inhibition in the maximal percentage decrease in FEV1; the area above the FEV1-time curve; and time to recovery of FEV1 at days 1 to 3, week 4, and week 8 of treatment.Results: By day 3, similar and statistically significant reductions in maximal percentage decrease in FEV1 were seen with both therapies. Sustained improvement occurred in the montelukast group at weeks 4 and 8; at these time points, the bronchoprotective effect of salmeterol decreased significantly. At week 8, the percentage inhibition in the maximal percentage decrease in FEV1 was 57.2% in the montelukast group and 33.0% in the salmeterol group (P = 0.002). By week 8, 67% of patients receiving montelukast and 46% of patients receiving salmeterol had a maximal percentage decrease in FEV1 of less than 20%.Conclusions: The bronchoprotective effect of montelukast was maintained throughout 8 weeks of study. In contrast, significant loss of bronchoprotection at weeks 4 and 8 was seen with salmeterol. Long-term administration of montelukast provided consistent inhibition of exercise-induced bronchoconstriction at the end of the 8-week dosing interval without tolerance. [ABSTRACT FROM AUTHOR]

Background: Though variable, many major metropolitan cities reported profound and unprecedented increases in out-of-hospital cardiac arrest (OHCA) in early 2020. This study examined the relative magnitude of those increases and their relationship to COVID-19 prevalence., Methods: EMS (9-1-1 system) medical directors for 50 of the largest U.S. cities agreed to provide the aggregate, de-identified, pre-existing monthly tallies of OHCA among adults (age >18 years) occurring between January and June 2020 within their respective jurisdictions. Identical comparison data were also provided for corresponding time periods in 2018 and 2019.  Equivalent data were obtained from the largest cities in Italy, United Kingdom and France, as well as Perth, Australia and Auckland, New Zealand., Findings: Significant OHCA escalations generally paralleled local prevalence of COVID-19. During April, most U.S. cities (34/50) had >20% increases in OHCA versus 2018-2019 which reflected high local COVID-19 prevalence. Thirteen observed 1·5-fold increases in OHCA and three COVID-19 epicenters had >100% increases (2·5-fold in New York City). Conversely, cities with lesser COVID-19 impact observed unchanged (or even diminished) OHCA numbers. Altogether ( n  = 50), on average, OHCA cases/city rose 59% during April ( p  = 0·03). By June, however, after mitigating COVID-19 spread, cities with the highest OHCA escalations returned to (or approached) pre-COVID OHCA numbers while cities minimally affected by COVID-19 during April (and not experiencing OHCA increases), then had marked OHCA escalations when COVID-19 began to surge locally. European, Australian, and New Zealand cities mirrored the U.S. experience., Interpretation: Most metropolitan cities experienced profound escalations of OHCA generally paralleling local prevalence of COVID-19.  Most of these patients were pronounced dead without COVID-19 testing., Funding: No funding was involved. Cities provided de-identified aggregate data collected routinely for standard quality assurance functions., Competing Interests: None of the authors or contributing investigators have any conflict of interest with respect to this observational, epidemiological, population-based cross-sectional research study which was based on routinely-collected public agency data sets., (© 2021 The Authors.)

Background: Chronic idiopathic urticaria (CIU) is the most common type of chronic urticaria, and pruritus is the most prominent symptom. Antihistamines are the first-line treatment for CIU. Sedation and anticholinergic adverse effects are often experienced with the first-generation antihistamines and there is a risk of cardiovascular adverse effects and drug interactions with some second-generation agents. Hence, new treatment options are needed. Desloratadine is a new, potent, nonsedating antihistamine that has an excellent cardiovascular safety profile., Methods: This was a multicenter, randomized, double-blind, placebo-controlled study designed to determine the efficacy and safety of desloratadine in the treatment of moderate-to-severe CIU. A total of 190 patients, aged 12-79 years, with at least a 6-week history of CIU and who were currently experiencing a flare of at least moderate severity, were randomly assigned to therapy with desloratadine 5 mg or placebo once daily for 6 weeks. Twice daily, patients rated the severity of CIU symptoms (pruritus, number of hives, and size of largest hive), as well as the impact of CIU symptoms on sleep and daily activity. Patients and investigators jointly evaluated therapeutic response and overall condition. Safety evaluations included the incidence of treatment-emergent adverse events, discontinuations due to adverse events, and changes from baseline in vital signs, laboratory parameters, and ECG intervals., Results: Desloratadine was superior to placebo in controlling pruritus and total symptoms after the first dose and maintained this superiority to the end of the study. Measures of sleep, daily activity, therapeutic response, and global CIU status were also significantly better with desloratadine after the first dose; these clinical benefits were also maintained throughout the 6-week study. No significant adverse events occured., Conclusions: Desloratadine 5 mg daily is a safe and effective treatment for CIU with significant benefits within 24 h and maintained through the treatment period.

Background: Aerosolized asthma medications with chlorofluorocarbon (CFC) propellants are being phased out because of environmental concerns about the ozone layer. Medications are being reformulated with non-ozone-depleting propellants., Objective: To evaluate the clinical comparability of albuterol sulfate formulated in a new hydrofluoroalkane-134a (HFA) propellant (Ventolin HFA Inhalation Aerosol), and conventional CFC-containing albuterol (Ventolin Inhalation Aerosol) in children with asthma., Design: Randomized, double-blind, placebo-controlled 2-week clinical trial with a 1- to 2-week run-in period. During the run-in, patients took Ventolin CFC as needed. Patients (n = 135) aged 4 to 11 years with asthma then were assigned randomly to treatment with Ventolin HFA, Ventolin CFC, or placebo administered 4 times daily via metered-dose inhaler for 2 weeks. All patients were allowed rescue albuterol use in matching propellant as needed for relief of breakthrough symptoms. The main outcome measure was the mean percentage of predicted peak expiratory flow (PEF) after the morning dose of study drug on day 1 and after 2 weeks as assessed by results of 6-hour serial tests., Results: At day 1, the mean (+/- SE) percentage of predicted PEF increased postdose by 14% (+/- 1%) in the Ventolin HFA group and 13% (+/- 1%) in the Ventolin CFC group compared with 6% (+/- 2%) in the placebo group (P

Background: Inhaled corticosteroid therapy in severe persistent asthma has been shown to reduce or eliminate oral corticosteroid (OCS) use while retaining effective asthma control., Objective: We sought to evaluate the ability of mometasone furoate (MF) delivered by means of dry powder inhaler to reduce daily oral prednisone requirements in OCS-dependent patients with severe persistent asthma., Methods: We performed a 12-week, double-blind, placebocontrolled trial (21 centers, 132 patients) comparing 2 doses of MF (400 and 800 microg administered twice daily) with placebo, followed by a 9-month open-label phase in which 128 patients received treatment with MF., Results: At the endpoint of the double-blind trial, MF 400 and 800 mg twice daily reduced daily OCS requirements by 46.0% and 23.9%, respectively, whereas placebo increased OCS requirements by 164.4% (P <.01). Oral steroids were eliminated in 40%, 37%, and 0% of patients in the MF 400 and 800 mg twice daily and placebo groups, respectively. Pulmonary function and quality of life significantly increased for MF-treated patients. Further reductions in OCS requirements were achieved with long-term MF treatment in the open-label phase., Conclusion: MF inhaled orally as a dry powder is an effective alternative to systemic corticosteroids in patients with severe persistent asthma.

Objective: Intranasal corticosteroids are used widely for the treatment of allergic rhinitis because they are effective and well tolerated. However, their potential to suppress growth of pediatric subjects with allergic rhinitis continues to be a concern, particularly in light of reports of growth suppression after treatment with intranasal beclomethasone dipropionate or intranasal budesonide (see the article by Skoner et al in this month's issue). A 1-year study of prepubertal patients between 3 and 9 years of age with perennial allergic rhinitis was conducted to assess the effects on growth of mometasone furoate aqueous nasal spray (MFNS), a new once-daily (QD) intranasal corticosteroid with negligible bioavailability., Methods: This was a randomized, placebo-controlled, double-blind, multicenter study. Ninety-eight subjects were randomized to treatment with either MFNS 100 microg QD or placebo for 1 year. Each subject's height was required to be between the 5th and 95th percentile at baseline, and skeletal age at screening was required to be within 2 years of chronological age, as determined by left wrist x-rays. Washout periods for medications that affect either childhood growth or allergic rhinitis symptoms were established based on estimated period of effect, and these medications were prohibited during the study. However, short courses of either oral prednisone lasting no longer than 7 days or low-potency topical dermatologic corticosteroids lasting no longer than 10 days were permitted if necessary. Height was measured with a calibrated stadiometer at baseline and at 4, 8, 12, 26, 39, and 52 weeks, and the primary safety variable was the change in standing height. The rate of growth was also calculated for each subject as the slope (linear regression) of the change in height from baseline using data from all visits of subjects who had at least 2 visits. Hypothalamic-pituitary-adrenocortical- (HPA)-axis function was assessed via cosyntropin stimulation testing at baseline and at 26 and 52 weeks. All analyses were based on all randomized subjects (intent-to-treat principle). The change from baseline in standing height was analyzed by a 2-way analysis of variance that extracted sources of variation attributable to treatment, center, and treatment-by-center interaction., Results: Demographic characteristics were similar at baseline. Eighty-two subjects completed the study (42 in the MFNS group and 40 in the placebo group), and 93% of subjects achieved at least 80% compliance with therapy. After 1 year of treatment, no suppression of growth was seen in subjects treated with MFNS, and mean standing heights were similar for both treatment groups at all time points. For the primary safety variable (change in height from baseline), both treatment groups were similar at all time points except for weeks 8 and 52. Subjects treated with MFNS had a slightly greater mean increase in height than subjects treated with placebo at these time points: the change in height was 6.95 cm versus 6.35 cm at the 1-year time point. However, the rate of growth (.018 cm/day) averaged for all time points over the course of the study was similar for both treatment groups. Additional analyses found that MFNS did not retard growth in any sex or age subgroup of subjects. The use of exogenous corticosteroids other than the study drug was also similar among the 2 treatment groups. Results from cosyntropin stimulation testing confirmed the absence of systemic effects of MFNS. The change from baseline in the difference between prestimulation and poststimulation levels was similar for both treatment groups after 1 year of treatment, with no evidence of HPA-axis suppression in MFNS-treated subjects at any time point. Incidences of treatment-related adverse events were similar for both treatment groups, with 16% of MFNS-treated subjects reporting adverse events, compared with 22% of placebo-treated subjects., Conclusions: (ABSTRACT TRUNCATED)

Background: A powder formulation of salmeterol has been shown to prevent exercise-induced bronchospasm (EIB) in asthmatic children and adults; however, the delivery device (Diskhaler; Glaxo Wellcome Inc, Research Triangle Park, NC) must be reloaded after 4 doses. A new multidose powder inhaler (Diskus) provides 60 doses of salmeterol in a blister pack presentation with a dose counter., Objective: To evaluate the safety and efficacy of 50-microg salmeterol powder via two different delivery systems (Diskhaler and Diskus) in preventing EIB in asthmatic children., Study Design: A randomized, double-blind, double-dummy, single-dose, placebo-controlled, three-way crossover study was conducted in 24 children 4 to 11 years of age demonstrating EIB and mild to moderate asthma. Serial forced expiratory volume in 1 second (FEV(1)) was measured before and after treadmill exercise challenges conducted at 1, 6, and 12 hours after study drug administration. Adverse events were also assessed., Results: During all exercise challenges, EIB-mediated reductions in FEV(1) were minimized or prevented in patients receiving single doses of salmeterol powder compared with placebo. Single doses of salmeterol powder delivered via either system were equally effective in preventing EIB. There were no drug-related adverse events, cardiovascular, or other clinically relevant safety concerns., Conclusions: Single doses of salmeterol powder delivered by either delivery system are safe and effective in preventing EIB for >/=12 hours in asthmatic children.

Background: The efficacy and safety of mometasone furoate aqueous nasal spray (MFNS; Nasonex) 200 microg once daily for the treatment and prophylaxis of seasonal allergic rhinitis (SAR) and treatment of perennial rhinitis have been demonstrated in adults. However, the dose response of MFNS in pediatric patients has not yet been characterized., Objective: This study was conducted to determine the dose-response relationship of 3 different doses of MFNS in a pediatric population., Methods: This was a multicenter, double-blind, active- and placebo-controlled study of 679 children 6 to 11 years of age with histories of SAR and documented positive skin test responses. Patients were randomized to one of the following treatment groups for 4 weeks: MFNS 25 microgram once daily, MFNS 100 microgram once daily, MFNS 200 microgram once daily, beclomethasone dipropionate 84 microgram twice daily (168 microgram/day), or placebo. Physician evaluations were performed at days 4, 8, 15, and 29, and patient evaluations were analyzed for days 1 to 15 and 16 to 29., Results: The mean reduction from baseline in physician-evaluated total nasal symptom scores at day 8 (the primary efficacy variable) was significantly greater in the MFNS and beclomethasone dipropionate groups than in the placebo group (P

Background: Perennial rhinitis is a common condition that affects up to 10% to 20% of the population. Multiple agents are frequently administered since no single agent provides complete relief. Studies assessing the benefit/risk of combined therapy are important especially for newly approved agents such as ipratropium bromide nasal spray 0.03%, a topical anticholinergic agent, approved specifically for the treatment of rhinorrhea in allergic and non-allergic perennial rhinitis., Objective: To compare the efficacy and safety of the combined use of ipratropium bromide nasal spray 0.03% (42 microg per nostril tid) and beclomethasone dipropionate nasal spray (84 microg per nostril bid) against that of either active agent alone for the treatment of rhinorrhea., Design: Multicenter, 6-week, double-blind, randomized active- and placebo-controlled, parallel trial., Setting: Allergist and general practitioner clinical practices., Patients: Five hundred thirty-three patients with perennial rhinitis (279 allergic and 274 non-allergic), 8 to 75 years of age, who had at least a mild degree of severity of rhinorrhea for a minimum of 2 hours per day during the 1 week screening period as well as congestion or sneezing also of at least mild severity., Intervention: Either (1) ipratropium bromide nasal spray 0.03% (42 microg per nostril tid) plus beclomethasone dipropionate nasal spray (84 microg per nostril bid), (2) ipratropium bromide nasal spray 0.03% (42 microg per nostril tid) alone, (3) beclomethasone dipropionate nasal spray (84 microg per nostril bid) alone, or (4) vehicle [matching placebo nasal spray for the ipratropium bromide (2 sprays per nostril tid)] or beclomethasone dipropionate (2 sprays per nostril bid)., Main Outcome Measure: Severity and duration of rhinorrhea, and patient and physician global assessment of control of rhinorrhea., Results: Ipratropium bromide nasal spray plus beclomethasone nasal spray was more effective than either active agent alone or vehicle in reducing the average severity and duration of rhinorrhea during 4 weeks of treatment. The advantage of ipratropium bromide plus beclomethasone nasal spray was evident by the first day of combined treatment and continued throughout the 2-week treatment period. Ipratropium bromide nasal spray had a faster onset of action during the first week of treatment and reduced the duration of rhinorrhea more than beclomethasone. Beclomethasone nasal spray was more effective in reducing the severity of congestion and sneezing than ipratropium. In patients who had not responded well to a nasal steroid prior to participation in the study based on a questionnaire administered at screening, ipratropium bromide was as effective in the steroid non-responders as steroid responders, whereas beclomethasone was more effective in steroid responders. Combined active therapy was well tolerated with no increase in adverse events over that seen previously with ipratropium bromide or beclomethasone nasal spray alone., Conclusions: The combined use of ipratropium bromide nasal spray with beclomethasone dipropionate nasal spray is more effective than either active agent for the treatment of rhinorrhea, and does not result in a potentiation of adverse drug reactions. Ipratropium bromide nasal spray 0.03% alone should be considered in patients for whom rhinorrhea is the primary symptom, and its use in combination with a nasal steroid should be considered in patients where rhinorrhea is one of the predominant symptoms, or in patients with rhinorrhea not fully responsive to other therapy.

Objective: To determine the effects of zafirlukast on exercise-induced bronchoconstriction in children., Study Design: Exercise challenges were done 4 hours after single oral doses of zafirlukast or placebo were administered in asthmatic children (6 to 14 years) treated with beta 2-agonists alone. Subjects randomized to treatment had a >/=20% decrease in forced expiratory volume in 1 second (FEV1 ) after a screening challenge. In a randomized, double-blind, 3-way, crossover design, group 1 (n = 20) received placebo and 5 and 20 mg zafirlukast, and group 2 (n = 19) received placebo and 10 and 40 mg zafirlukast. Maximal percentage fall in FEV1, area under the curve, and time to recovery of FEV1 to within 5% of baseline after the challenge were compared with analysis of variance., Results: Mean values for maximal fall in FEV1 ranged from -8.7% +/- 1.7% to -11.1% +/- 1.9% after zafirlukast compared with -17.1% +/- 1.8% and -16.3% +/- 1.9% after placebo. Differences from placebo for fall in FEV1 and area under the curve were significant (P

Chlorofluorocarbon (CFC) propellants deplete stratospheric ozone. Production and use of CFCs, except for certain critical exemptions, has been prohibited by the Montreal Protocol. Use of CFCs as propellants in metered-dose inhalers (MDIs) is still allowed, but the U.S. Food and Drug Administration is planning the transition to alternative propellants for use in MDIs. Hydrofluoroalkane-134a (HFA), a non-ozone-depleting propellant, has been used to reformulate albuterol (HFA albuterol). This study evaluates whether comparable safety and efficacy continues for 12 weeks after patients with asthma are switched from CFC albuterol to HFA albuterol. Patients with asthma stabilized on CFC albuterol during a 12-week safety and efficacy trial were randomized to either continue receiving CFC albuterol or to be switched to receive HFA albuterol in a yearlong safety and efficacy trial. Safety and efficacy were compared over the first 12 weeks of the yearlong trial between patients who had remained on CFC albuterol and those who had been switched to HFA albuterol. Bronchodilator efficacy was evaluated by serial spirometry for 6 hr after the patients self-administered the study drug in the clinic. Safety was assessed by measuring changes in pulse rate, blood pressure, and electrocardiogram (ECG) intervals after dosing with study drug, monitoring adverse events, and performing prestudy and poststudy laboratory testing and physical examinations. No significant differences in bronchodilator efficacy between the patients continuing to receive CFC albuterol and those switched to HFA albuterol were found in the 12 weeks after the switch. No differences between the two products were found for changes in pulse rate, blood pressure, and ECG intervals. Adverse event profiles were similar for the two products, except the patients remaining on CFC albuterol reported increased asthma symptoms and rhinitis significantly more often than the patients switched to HFA albuterol. No clinically meaningful changes in laboratory tests or physical examinations were found in either treatment group. Patients with asthma switched from CFC albuterol to HFA albuterol receive comparable bronchodilation with a similar safety profile as those continuing to receive CFC albuterol.

Tri-Nasal Nasal Spray is an investigational solution of triamcinolone acetonide (TAA) currently being evaluated as a treatment for allergic rhinitis. The safety and efficacy of 200 and 400 micrograms once daily doses of Tri-Nasal Nasal Spray, an active control (440 micrograms once daily of Nasacort Nasal aerosol), and Tri-Nasal Nasal Spray placebo were compared over a 2-week treatment period in a double-blind (the Nasacort treatment was not blinded), parallel design trial. A total of 377 adult patients in 13 centers were enrolled during the grass pollen season. The primary efficacy variable was the weekly average of the SSI (Symptom Severity Index), the sum of daily nasal congestion, rhinorrhea, and sneezing severity scores from the patient diary. A total of 355 patients completed the study. All active treatments were significantly more effective than placebo in relieving nasal symptoms at each treatment week. The 400 micrograms Tri-Nasal Nasal Spray and Nasacort treatments had a rapid onset of action, demonstrating significant improvement in the SSI versus placebo by the second day of treatment. Results for the individual nasal symptoms and other secondary efficacy measures paralleled those of the primary efficacy variables. Tri-Nasal Nasal Spray and Nasacort were comparable in safety, and in treating the nonocular symptoms of seasonal allergic rhinitis.

Background: Patients with mild asthma frequently have only exercise-induced bronchoconstriction, a symptom of inadequate control of asthma. We evaluated the ability of montelukast, a leukotriene-receptor antagonist, to protect such patients against exercise-induced bronchoconstriction., Methods: We randomly assigned 110 patients (age, 15 to 45 years) with mild asthma and a decrease in the forced expiratory volume in one second (FEV1) of at least 20 percent after exercise on two occasions during a placebo run-in period to receive 10 mg of montelukast (54 patients) or placebo (56 patients) once daily at bedtime for 12 weeks in a double-blind study. Treatment was followed by a two-week, single-blind washout period during which all patients received placebo. Exercise challenges were performed at base line; 20 to 24 hours after dosing at weeks 4, 8, and 12; and at the end of the washout period. The primary end point was the area under the curve for FEV1 (expressed as the percent change from base-line values) in the first 60 minutes after exercise. This measure summarized the extent and duration of bronchoconstriction after exercise., Results: At 12 weeks, montelukast therapy offered significantly greater protection against exercise-induced bronchoconstriction than placebo therapy (expressed as the percentage of inhibition of the end points), as evidenced by the improvement in the area under the FEV1 curve (degree of inhibition, 47.4 percent; P=0.002). Montelukast therapy was also associated with a significant improvement in the maximal decrease in FEV1 after exercise (P=0.003) and the time from the maximal decrease in FEV1 to the return of lung function to within 5 percent of pre-exercise values (P=0.04). The differences between groups in the various measures of lung function were similar at 4, 8, and 12 weeks; there was no evidence of rebound worsening of lung function in the montelukast group after the washout period. After 12 weeks of treatment, patients in the montelukast group were more likely to rate their asthma control as better and less likely to require rescue therapy with a beta-agonist during or after exercise challenge. The rates of adverse events were similar in the two groups., Conclusions: As compared with placebo, once-daily treatment with montelukast provided significant protection against exercise-induced asthma over a 12-week period. Tolerance to the medication and rebound worsening of lung function after discontinuation of treatment were not seen.

Background: The efficacy and safety of salmeterol powder have not previously been evaluated in children with asthma in the United States., Objective: The efficacy and safety of salmeterol powder versus placebo were compared in children between the ages of 4 and 11 years with chronic persistent asthma., Methods: A randomized, double-blind, placebo-controlled, parallel group trial was performed at 11 clinical centers. Two hundred seven patients were randomly assigned to receive 50 microg salmeterol powder or placebo (and albuterol as needed) twice daily via a breath-actuated device for 12 weeks. Twelve-hour serial pulmonary function assessments were conducted on day 1 and at week 12. Daily recordings of morning and evening peak expiratory flow (PEF), supplemental albuterol use, asthma symptoms, and nocturnal awakenings were assessed., Results: On day 1 and at week 12, weighted mean percent of predicted PEF (P < .001, day 1 and P=.008, week 12) and weighted mean forced expiratory volume in one second (P < .001, day 1 and week 12) were significantly higher at all timepoints evaluated over the 12-hour postdosing period in patients treated with salmeterol powder compared with placebo. Overall reductions in supplemental albuterol use and mean asthma symptom scores were also significantly greater in children administered salmeterol compared with placebo (P=.004 and P=.006, respectively). The frequency of adverse events was similar in the two treatment groups., Conclusion: Salmeterol powder (50 microg twice daily) is effective and safe in producing bronchodilation and relieving symptoms in children with chronic persistent asthma during 12 weeks of treatment.