The safety and efficacy of arformoterol and formoterol in COPD.

This study evaluated the safety and efficacy of arformoterol and formoterol over 6-months in subjects with COPD. In a multi-center, 6-month randomized, double-blind, double-dummy trial, subjects with COPD (mean FEV(1) 1.21 L, approximately 41.0% predicted) were randomized to receive either nebulized arformoterol (15 microg BID [n = 149][ARF 15], 25 microg BID [n = 147][ARF 25]), or racemic formoterol (12 microg BID [n = 147][FORM]) delivered by DPI. The proportion of subjects with any post-treatment adverse event for ARF 15, ARF 25 microg, and FORM was 67.8%, 76.2% and 66.7%, respectively, and those with at least one COPD exacerbation was 32.2%, 30.6%, and 22.4%, respectively. Pulmonary function improved for all treatment groups and was maintained throughout the study. Mean change from baseline at 6-months for ARF 15, ARF 25 and FORM in peak FEV(1) was 0.30L, and 0.34L, and 0.26L, respectively, in 24-hour trough FEV(1) was, 0.10L, 0.14L, and 0.09L, and in inspiratory capacity was, 0.20L, 0.37L, and 0.23L. Dyspnea, (mean Transition Dypsnea Index (TDI) focal score) improved in all treatment arms (ARF 15: 1.4, ARF 25: 1.5, and FORM: 1.4) at 6 months, as did rescue short-acting beta(2)-agonists use (mean range: -1.1 to -1.3 actuations/day) and ipratropium bromide (mean range: -0.3 to -0.8 actuations/day). Health status, measured by St George's Respiratory Questionnaire, improved from baseline at 6-months in all treatment groups (mean change: -3.7 to -6.8). In this 6-month study, arformoterol and formoterol were well-tolerated, and their use was associated with improvement in pulmonary function and health status in subjects with COPD with no apparent development of tolerance.

Inhalation of vasoactive intestinal peptide in pulmonary hypertension.

Pulmonary hypertension (PH) leads to an increased right ventricular workload, cardiac failure and death. In idiopathic pulmonary arterial hypertension (PAH) the vasodilating vasoactive intestinal peptide (aviptadil) is deficient. The aim of the present study was to test the acute effects on haemodynamics and blood gases, and the safety, of a single dose of inhaled aviptadil in chronic PH. A total of 20 patients with PH (PAH in nine, PH in lung disease in eight and chronic thromboembolic PH in three) inhaled a single 100-microg dose of aviptadil during right-heart catheterisation. Haemodynamics and blood gases were measured. Aviptadil aerosol caused a small and temporary but significant selective pulmonary vasodilation, an improved stroke volume and mixed venous oxygen saturation. Overall, six patients experienced a pulmonary vascular resistance reduction of >20%. In patients with significant lung disease, aviptadil tended to improve oxygenation. The pulmonary vasodilating effect of aviptadil aerosol was modest and short-lived, did not cause any side-effects and led to a reduced workload of the right ventricle without affecting systemic blood pressure. Aviptadil inhalation tended to improve oxygenation in patients with significant lung disease. Further studies are needed to evaluate the full therapeutic potential of aviptadil aerosol, including higher doses and chronic treatment.

A pharmacokinetic/pharmacodynamic study comparing arformoterol tartrate inhalation solution and racemic formoterol dry powder inhaler in subjects with chronic obstructive pulmonary disease.

BACKGROUND: Arformoterol is a single-isomer (R,R-formoterol) nebulized long-acting beta(2)-agonist approved for use in patients with chronic obstructive pulmonary disease (COPD). Exposure (plasma concentrations of (R,R)-formoterol) and forced expiratory volume in 1s (FEV(1)) were compared for 15 microg nebulized arformoterol and 12 and 24 microg racemic formoterol (containing 6 and 12 microg (R,R)-formoterol, respectively) delivered by dry powder inhaler (DPI). METHODS: An open-label, randomized, three-way crossover study in 39 subjects with COPD (FEV(1) 1.4L, 44.4% predicted). Twice-daily treatments included nebulized arformoterol (15 microg) and racemic formoterol DPI (12 and 24 microg) for 14 days. Plasma concentrations of (R,R)- and (S,S)-formoterol were determined on days 1 and 14 of each treatment period. Airway function efficacy endpoints included the percent change in trough FEV(1) from baseline on day 14 of each treatment period. RESULTS: At steady state, exposure to (R,R)-formoterol was similar following nebulized 15 microg arformoterol (C(max): 6.5 pg/mL; AUC(0-tau): 56.5 pgh/mL) and 12 microg racemic formoterol DPI (C(max): 6.2 pg/mL; AUC((0-)(tau)()): 46.3 pgh/mL). The geometric mean ratios between these two treatments (90% confidence intervals) for C(max) and AUC((0-)(tau)()) were 0.91 (0.76, 1.09) and 1.16 (1.00, 1.35), respectively. Treatment with 24 microg racemic formoterol DPI resulted in dose proportionally higher (R,R)-formoterol: C(max) (10.8 pg/mL) and AUC((0-)(tau)()) (83.6 pgh/mL). Detectable (S,S)-formoterol was consistently measured only after treatment with racemic formoterol. The mean percent increase in trough FEV(1) was 19.1% in the arformoterol group, and 16.0% and 18.2% in the 12 and 24 microg racemic formoterol groups, respectively. Changes in (R,R)-formoterol concentrations over time paralleled changes in FEV(1). CONCLUSIONS: In this study, plasma exposure to (R,R)-formoterol was similar for nebulized 15 microg arformoterol and 12 microg racemic formoterol DPI, and 40% lower than 24 microg racemic formoterol DPI. There was no evidence of chiral interconversion following treatment with arformoterol. Finally, temporal changes in airway function in all treatment groups corresponded to changes in (R,R)-formoterol plasma concentrations.

Arformoterol and salmeterol in the treatment of chronic obstructive pulmonary disease: a one year evaluation of safety and tolerance.

INTRODUCTION: Concerns have been raised regarding the safety of extended use of long-acting beta2-agonists (LABAs). The safety of arformoterol (50 microg QD), and salmeterol (42 microg BID), was assessed over 12 months in subjects with COPD. The study also examined the occurrence of tolerance with these agents, i.e. whether improvement in airway function diminished or frequency of exacerbations increased with 12-months of use. METHODS: Subjects with COPD (mean FEV1 1.2 L, ~41% predicted) were enrolled in the study and randomized to receive nebulized arformoterol 50 microg QD (n = 528) or salmeterol 42 microg BID (MDI; n = 265) in a prospective, multicenter, open-label, 12-month trial. The frequency of adverse events, COPD exacerbations, and use of short-acting bronchodilator agents were assessed throughout the study period. Pulmonary function was also examined. RESULTS: Among treated subjects, the frequency of adverse events was similar for those taking arformoterol (90.5%) and salmeterol (88.3%). Tremor was more frequent among subjects treated with arformoterol (13.4%) than those treated with salmeterol (1.1%). The frequency of COPD exacerbations did not increase over 12 months for arformoterol and salmeterol (weeks 0-13: 15.7% and 11.7%, respectively; weeks 39-52: 10.0% and 9.4%, respectively). Supplemental ipratropium bromide and rescue racemic albuterol use decreased for both groups by 0.8 to 1.5 actuations/day, decreases that remained stable throughout the 52-week study. Mean predose (trough) FEV1 improved for arformoterol and salmeterol at week 13 (7.1% +/- 17.0 and 7.6% +/- 17.8, respectively) and the improvement continued at week 52 (5.9% and 6.2%, respectively). Mean peak percent predicted postdose FEV1 over the course of the 52-week study declined by about 2% for both treatments, but throughout was higher for arformoterol than for salmeterol. CONCLUSION: In this trial, both arformoterol 50 microg QD and salmeterol 42 microg BID were well tolerated in patients with COPD. Both LABAs produced effective bronchodilation and their use was not associated with the development of clinically meaningful tolerance over a 1-year treatment period.

Distribution of therapeutic response in asthma control between oral montelukast and inhaled beclomethasone.

The distribution of responses in study populations provides a novel method of comparing the benefit of two treatments. This 6-week, randomised, placebo-controlled, double-blind study compared the effectiveness of oral montelukast with inhaled beclomethasone in chronic asthma by assessing the distribution and overlap of patient responses to therapy, as measured by a clinical outcome (asthma control days). A total of 730 adult patients with asthma, age 15-65 yrs, with a forced expiratory volume in one second (FEV1) at baseline of 50-85% of predicted and > or = 15% improvement in FEV1 after inhaled beta-agonist were enrolled. After a 2-week placebo run-in period, patients were randomly allocated to receive montelukast (10 mg once daily), inhaled beclomethasone (200 microg twice daily) or placebo. The primary end-point (per cent of asthma control days) was compared between treatments as the overlap in the response distributions. The overlap of the distribution of responses between the montelukast and beclomethasone groups was 89% for per cent asthma control days and 96% for change from baseline in FEV1. The mean (+/-SD) per cent asthma control days in the montelukast and beclomethasone groups was significantly higher than that in the placebo group (placebo 40.0+/-35.8, montelukast 50.7+/-37.1, beclomethasone 57.9+/-36.1). The mean differences between montelukast and placebo, beclomethasone and placebo, and montelukast and beclomethasone were significant. The mean per cent change (+/-SD) from baseline in FEV1 was 12.1+/-18.7 and 13.9+/-20.8 in the montelukast and beclomethasone groups, respectively, and significantly greater than that in the placebo group (6.4+/-20.1); there was no significant difference between the montelukast and beclomethasone groups in mean values or response distribution. There was also no difference among treatment groups in the frequency of adverse experiences. A comparison of the response distribution is an important approach to comparing therapies; montelukast and beclomethasone provided similar response distributions for the end-point of per cent asthma control days over a 6-week treatment period.

Low-dose levalbuterol in children with asthma: safety and efficacy in comparison with placebo and racemic albuterol.

BACKGROUND: Racemic albuterol (RAC) is an equal mixture of (R)-albuterol and (S)-albuterol. Only the (R)-isomer, levalbuterol (LEV), is therapeutically active. Lower doses of LEV, devoid of (S)-albuterol, have demonstrated efficacy comparable to that of higher doses of the (R)-isomer administered as a component of RAC. OBJECTIVE: The purpose of this study was to determine whether LEV results in improved safety and efficacy in children. METHODS: Asthmatic children aged 4 to 11 years (n = 338; FEV(1), 40% to 85% of predicted) participated in this multicenter, randomized, double-blinded study and received 21 days of 3-times-a-day treatment with nebulized LEV (0.31 or 0.63 mg), RAC (1.25 or 2.5 mg), or placebo. The primary endpoint was FEV(1) (peak percent change). Adverse events, clinical laboratory test results, vital signs, and electrocardiograms were evaluated for safety. RESULTS: All active treatments significantly improved the primary endpoint in comparison with placebo (P < .001). Significant differences in FEV(1) were noted immediately after nebulization (median change, 2.0%, 19.0%, 18.1%, 12.4%, and 15.6% for placebo, LEV 0.31 and 0.63, RAC 1.25 and 2.5 mg, respectively; P < .05 vs placebo; P < .05 for LEV 0.31 and 0.63 vs RAC 1.25 mg). LEV 0.31 mg was the only treatment not different from placebo for changes in ventricular heart rate, QT(c) interval, and glucose (P > .05). All active treatments decreased serum potassium (range, -0.3 to -0.6; P < .002 vs placebo), and RAC 2.5 mg caused the greatest change (P < .005 vs other actives). In a patient subset with severe asthma, a dose-response relationship was observed for levalbuterol, indicating that higher doses were more effective. CONCLUSION: LEV was clinically comparable to 4- to 8-fold higher doses of RAC, and it demonstrated a more favorable safety profile. LEV 0.31 mg should be used as the starting dose in 4-11 year old children with mild to moderate persistent asthma. Patients with severe disease might benefit from higher doses.

Comparison of the effects of intravenous and oral montelukast on airway function: a double blind, placebo controlled, three period, crossover study in asthmatic patients.

BACKGROUND: Montelukast, a leukotriene receptor antagonist, improves parameters of asthma control including forced expiratory volume in one second (FEV(1)) when given orally to patients aged six years or older. This study was undertaken to compare the effect on FEV(1) of intravenous and oral montelukast and placebo during the 24 hour period following administration. METHODS: Fifty one asthmatic patients (FEV(1) 40-80% predicted and > or =15% improvement after inhaled beta agonist) were enrolled in a double blind, single dose, three period, crossover study to receive intravenous montelukast (7 mg), oral montelukast (10 mg), or placebo in a randomised fashion. The primary end point was area under the curve (AUC)(0-24 h) of the percentage change from baseline in FEV(1). Additional end points were maximum percentage change in FEV(1) and percentage change at different time points. RESULTS: Compared with placebo, intravenous and oral montelukast significantly increased the AUC(0-24 h) (means of 20.70%, 15.72%, and 7.75% for intravenous, oral and placebo, respectively; no statistical difference between intravenous and oral). The difference in least square means from placebo for intravenous montelukast was 13.27% (95% CI 7.07 to 19.46), p<0.001 and for oral montelukast was 7.44% (95% CI 1.20 to 13.68), p = 0.020. The maximum percentage change in FEV(1) was not significantly different for intravenous and oral montelukast (difference in least square means 6.78% (95% CI -0.59 to 14.15), p = 0.071). The mean percentage change in FEV(1) for intravenous montelukast was greater than for oral montelukast within the first hour (15.02% vs 4.67% at 15 min, p< or =0.001; 18.43% vs 12.90% at one hour, p<0.001 for intravenous and oral montelukast, respectively (placebo 3.05% at 15 minutes, 7.33% at one hour). Intravenous and oral montelukast were similar to placebo in the frequency of adverse events. CONCLUSIONS: The onset of action for intravenous montelukast was faster than for oral montelukast and the improvement in airway function lasted over the 24 hour observation period for both treatments. Although not well understood, there was a trend toward a greater improvement in FEV(1) with intravenous than with oral montelukast. These findings suggest that leukotriene receptor antagonists should be investigated as a treatment for acute severe asthma.

Quercetin sensitizes RBL-2H3 cells to polybasic mast cell secretagogues through increased expression of Gi GTP-binding proteins linked to a phospholipase C signaling pathway.

Polybasic secretagogues such as mastoparan, compound 48/80, substance P, and somatostatin stimulate secretion in rat peritoneal mast cells through direct activation of the heterotrimeric G protein, G(i-3). Cultured RBL-2H3 mast cells do not normally respond to these secretagogues, but, as reported here, they do so after prolonged exposure to the kinase inhibitor, quercetin. This inhibitor, which causes phenotypic changes in RBL-2H3 cells, induces a substantial increase (more than sevenfold) in the expression of alpha subunits of the pertussis toxin-sensitive G proteins, G(i-2) and G(i-3). Compound 48/80-induced secretion is associated with transient hydrolysis of phosphoinositides and a transient increase in cytosolic calcium ions. These responses are inhibited by pertussis toxin, and in addition, secretion is blocked by calcium chelation and the protein kinase C inhibitor, Ro31-7549. These results delineate a pathway for compound 48/80-induced secretion in mast cells via Gi protein(s), phospholipase C, calcium, and protein kinase C. The results also imply that phospholipase C, most likely phospholipase Cbeta3, can be transiently activated in RBL-2H3 cells by subunits of Gi proteins to induce cellular responses.

Mitogen-activated protein (MAP) kinase regulates production of tumor necrosis factor-alpha and release of arachidonic acid in mast cells. Indications of communication between p38 and p42 MAP kinases.

Aggregation of the high affinity IgE receptor (FcepsilonRI) in a mast cell line resulted in activation of the p42 and the stress-activated p38 mitogen-activated protein (MAP) kinases. Selective inhibition of these respective kinases with PD 098059 and SB 203580 indicated that p42 MAP kinase, but not p38 MAP kinase, contributed to the production of the cytokine, tumor necrosis factor-alpha, and the release of arachidonic acid in these cells. Neither kinase, however, was essential for FcepsilonRI-mediated degranulation or constitutive production of tumor growth factor-beta. Studies with SB 203580 and the p38 MAP kinase activator anisomycin also revealed that p38 MAP kinase negatively regulated activation of p42 MAP kinase and the responses mediated by this kinase.

Downstream signals initiated in mast cells by Fc epsilon RI and other receptors.

The significant contributions this past year to our understanding of IgE receptor (Fc epsilon RI) signaling in mast cells include studies with truncated Syk in a vaccinia expression system and Syk-negative variants of rat basophilic (RBL-2H3) cells. These studies demonstrate an essential role for Syk in initiating signals for secretion and release of arachidonic acid via phospholipase A2 and mitogen-activated protein kinase. A newly recognized addition to the repertoire of Fc epsilon RI-mediated signaling systems is the activation of sphingosine kinase, which contributes to calcium mobilization in mast cells. Advances have been made in our understanding of other receptors that regulate proliferation and differentiation of mast cells, and in our understanding of the ability of mast cells to mount acquired and acute responses to antigenic and bacterial challenge.

Constitutive and inducible mechanisms for synthesis and release of cytokines in immune cell lines.

We found that production and release of two functionally antagonistic cytokines, TGF-beta and TNF-alpha, were regulated differently in the mast cell, T cell, and macrophage cell lines RBL-2H3, MLA-144, and U-937, respectively. TGF-beta was produced and released constitutively in all three cell lines. When, however, the cell lines were stimulated with Ag, LPS, or calcium ionophore plus PMA, acceleration of release and some additional production of TGF-beta were apparent. In contrast, TNF-alpha was produced and released only when these lines were stimulated. Although neither the glucocorticoid, dexamethasone, nor the protein kinase C inhibitor, Ro31-7549, suppressed constitutive production or release of TGF-beta, these agents inhibited TNF-alpha production and the inducible component of TGF-beta production noted above. The release of these cytokines, whether constitutive or inducible, was dependent on Golgi-processing as indicated by inhibition with brefeldin A. Therefore, although both types of cytokines were processed by Golgi, only TNF-alpha and the inducible component of TGF-beta production were protein kinase C or steroid-regulated processes. These findings suggested that constitutive and inducible pathways exist for production and release of cytokines and that the inducible pathways can be selectively suppressed by pharmacologic agents.

Enhancement of TNF-alpha synthesis by overexpression of G alpha z in a mast cell line.

Ag stimulation of mast cells via the IgE receptor (Fc epsilon RI) elicits production and release of numerous cytokines. This activation of Fc epsilon RI initiates various tyrosine kinase-dependent signaling cascades, which ultimately result in the de novo synthesis of cytokines. To date, no heterotrimeric G proteins have been implicated in this process. Here we report that the alpha subunit of the heterotrimeric G protein, Gz, can regulate production of the cytokine, TNF-alpha. The alpha subunit was overexpressed in a cultured mast cell line (RBL-2H3) known to contain G alpha z. In stimulated cells, overexpression of G alpha z significantly enhanced the production of TNF-alpha. This effect of G alpha z appeared to be restricted in that constitutive synthesis of the cytokine, TGF-beta, and Ag-stimulation of the phosphoinositide-dependent secretory pathway were not significantly affected. Thus, G alpha z, a heterotrimeric G protein, appeared to modulate the stimulatory pathways for induction of TNF-alpha synthesis in RBL-2H3 cells.

Secretion of TNF from a rat mast cell line is a brefeldin A-sensitive and a calcium/protein kinase C-regulated process.

Stimulated mast cells and cognate cultured cell lines produce and secrete a variety of cytokines including TNF. Because the mechanism by which cytokines are delivered to the external milieu is unknown, the release of TNF was studied in a rat mast cell line (RBL-2H3 cells). In these cells, TNF was not constitutively expressed nor incorporated into secretory granules but was generated de novo upon cell stimulation. It was then released by a process analogous to constitutive secretion in that brefeldin A, an agent known to disrupt Golgi membranes in these cells, inhibited this release without inhibiting release of secretory granules. Unlike constitutive secretion, however, the secretion of TNF was highly regulated by Ca2+ and protein kinase C. Studies with various stimulants and inhibitors indicated that simultaneous mobilization of Ca2+ and activation of protein kinase C were sufficient signals for secretion although optimal production of TNF may be dependent on additional synergistic signals. Because suppression of Ca2+ mobilization or inhibition of protein kinase C alone abrogated TNF secretion, the process may be amenable to therapeutic intervention.

Studies with transfected and permeabilized RBL-2H3 cells reveal unique inhibitory properties of protein kinase C gamma.

To characterize protein kinase C (PKC) gamma, an isozyme found exclusively in brain and spinal cord, its cDNA was introduced into basophilic RBL-2H3 cells that lack this isozyme. The expression of PKC gamma significantly attenuated antigen-induced responses including hydrolysis of inositol phospholipids, increase in cytosolic calcium, and secretion of granules but enhanced antigen-induced release of arachidonic acid. Instead of a sustained increase in cytosolic calcium, antigen now induced calcium oscillations; possibly as a consequence of suppression of the phospholipase C activity and incomplete emptying of internal calcium stores. In addition, PKC gamma appeared to inhibit activation of other PKC isozymes because phorbol 12-myristate 13-acetate failed to act synergistically with the Ca(2+)-ionophore on secretion. This was confirmed in other studies where PKC gamma was shown to suppress the transduction of stimulatory signals by other isozymes of PKC on provision of these isozymes to PKC-depleted permeabilized cells. The studies in total indicated that only PKC gamma was capable of inhibiting both early and distal signals for secretion including those signals transduced by endogenous isozymes of PKC.

Serotonin induces constriction and relaxation of the guinea pig airway.

The response of guinea pig trachea to 5-hydroxytryptamine (serotonin; 5-HT) was investigated by studying tracheal strips suspended in organ chambers for isometric tension measurements. Serotonin concentrations of 0.1 to 10 microM produced concentration-dependent contractions, whereas at higher concentrations (10-300 microM) the agonist caused concentration-dependent relaxations. The 5-HT2 antagonist ketanserin shifted the bimodal 5-HT response-curve to the right (pA2 for ketanserin was 8.98). The 5-HT1A agonist, (+)-8-hydroxy-2-(di-N-propylamino)tetralin hydrobromide and 5-HT3 antagonist, ICS 205930 (3-tropanyl-indole-3-carboxylate) had no effect on the 5-HT-response curve. Incubation with atropine resulted in a depression of the maximal contractility and an increase in the EC50 without changing the bimodal nature of the concentration-response curve. Hexamethonium was able to block the atropine effect without significantly affecting the 5-HT concentration-response curve. Neither the constriction nor the relaxation was altered by propranolol, chlorpheniramine or capsaicin pretreatment. Histamine and carbachol preconstricted airways were also relaxed by 5-HT in a concentration-dependent fashion and this relaxation was antagonized by ketanserin (pKb for ketanserin in histamine preconstricted airways was 9.4). Epithelial denudation did not inhibit the 5-HT-induced relaxation. 5-HT stimulated inositol-monophosphate production which also exhibited a bimodal response and correlated well with the functional response. The above findings suggest that 5-HT causes both constriction and relaxation of the guinea pig airway, and that both responses are antagonized by a 5-HT2 receptor blocker. In addition, part of the constrictor response of 5-HT is mediated through a cholinergic preganglionic pathway. Finally, inositol-monophosphate production induced by 5-HT correlates with the functional response.

The role of echocardiography and CT in the diagnosis of cardiac tumors.

A young male who presented with atypical chest pain was found to have a primary cardiac tumor. Chest X-ray, electrocardiogram, and echocardiographic findings can be nonspecific. Differential diagnosis and the role of different diagnostic modalities including echocardiogram, computerized tomography and magnetic resonance imaging are discussed.

Continuously tunable ir lidar with applications to remote measurements of SO(2) and CH(4).

Remote atmospheric measurements of SO(2) and CH(4) were performed using a differential absorption lidar with a continuously tunable LiNbO(3) parametric oscillator and amplifier source in the 1.4-4.0-microm region. A comparison of injected gas concentration in a remotely located sample chamber showed excellent agreement with a SO(2) detection sensitivity of 0.9 ppm-km. An ambient level measurement of methane at the 1.66-microm overtone transition gave 3.9 +/- 0.7 ppm Performance predictions indicate an order of magnitude gain in sensitivity is possible with recently demonstrated tunable source improvements. The wide tuning range capability allows the measurement of numerous other pollutant molecules in the 1.4-4.0-microm region.