Effects of prostaglandin E1alpha cyclodextrin [corrected] treatment on endothelial dysfunction in patients with systemic sclerosis

OBJECTIVE

Systemic sclerosis (SSc) is characterized by an altered nitric oxide (NO): endothelin I ratio and by endothelial dysfunction.

AIMS

To verify the effects of prostaglandin E1 (PGE1) alpha-cyclodestrin treatment on endothelial function, quantified as flow-mediated dilation (FMD) of the radial artery.

METHODS

In 16 women with SSc (age 57 +/- 2.7 years, means +/- SE) in whom a diagnosis of SSc had been made several years earlier (7.1 +/- 1.2 years), FMD was evaluated by an echotracking technique on the radial artery, using trinitroglycerin vasodilation as a non-endothelial measure of the vessel's ability to increase its diameter maximally. FMD was evaluated after 4 months washout period and after 4 months cyclic infusion of PGE1 alpha-cyclodestrin. Expired NO was measured at the same time.

RESULTS

PGE1 alpha-cyclodestrin cyclic infusions did not modify systolic and diastolic blood pressure, heart rate or trinitroglycerin radial artery vasodilation. On the other hand, it induced a marked and significant increase in FMD of the radial artery, which was also accompanied by an increase in blood flow and expired NO.

CONCLUSIONS

Endothelial dysfunction and reduced FMD associated with SSc are improved by cyclic treatment with PGE1 alpha-cyclodestrin. This effect occurs together with a concomitant increase in expired NO, suggesting its direct positive influence on endothelial function. It may also partly explain the clinical beneficial effect of the drug in SSc.

Comparative Efficacy and Tolerability of Pholcodine and Dextromethorphan in the Management of Patients with Acute, Non-Productive Cough

INTRODUCTION

The aim of this study was to compare the efficacy and tolerability of pholcodine with that of dextromethorphan, one of the most used cough sedative products, in patients with acute, non-productive cough.

METHODS

129 adults with a diagnosis of acute, frequent, non-productive cough participated in a randomized, double-blind, parallel-group, multicenter trial. Medications were in a syrup formulation and were taken orally three times daily for 3 days. The efficacy endpoints were the change from baseline in the daytime and night-time cough frequency on 5-point scales at day 3, and cough intensity.

RESULTS

A reduction of 1.4 and 1.3 points in the mean daytime cough frequency at day 3 was seen in the pholcodine and dextromethorphan groups, respectively, in the per-protocol population. The reduction in mean night-time cough was 1.3 for both groups. Cough intensity reduction was 0.7 for pholcodine and 0.8 for dextromethorphan.

CONCLUSIONS

These findings indicate that the efficacy of a 3-day course of pholcodine is similar to that of dextromethorphan in the treatment of adult patients with acute, non-productive cough. Both medications were well tolerated.

Obstructive Sleep Apnea–Dependent and –Independent Adrenergic Activation in Obesity

No agreement exists as to the mechanisms responsible for the sympathetic hyperactivity characterizing human obesity, which has been ascribed recently to a chemoreflex stimulation brought about by obstructive sleep apnea rather than to an increase in body weight, per se. In 86 middle-age normotensive subjects classified according to body mass index, waist-to-hip ratio, and apnea/hypopnea index (overnight polysomnographic evaluation) as lean and obese subjects without or with obstructive sleep apnea, we assessed via microneurography muscle sympathetic nerve traffic. The 4 groups were matched for age, gender, and blood pressure values, the 2 obese groups with and without obstructive sleep apnea showing a similar increase in body mass index (32.4 versus 32.0 kg/m2, respectively) and waist-to-hip ratio (0.96 versus 0.95, respectively) compared with the 2 lean groups with or without obstructive sleep apnea (body mass index 24.3 versus 23.8 kg/m2 and waist-to-hip ratio 0.77 versus 0.76, respectively; P<0.01). Compared with the nonobstructive sleep apnea lean group, muscle sympathetic nerve activity showed a similar increase in the obstructive sleep apnea lean group and in the nonobstructive sleep apnea obese group (60.4+/-2.3 and 59.3+/-2.0 versus 40.9+/-1.8 bs/100 hb, respectively; P<0.01), a further increase being detected in obstructive sleep apnea subjects (73.1+/-2.5 bursts/100 heart beats; P<0.01). Our data demonstrate that the sympathetic activation of obesity occurs independently in obstructive sleep apnea. They also show that this condition exerts sympathostimulating effects independent of body weight, and that the obstructive sleep apnea-dependent and -independent sympathostimulation contribute to the overall adrenergic activation of the obese state.

Different effects of inhaled aspirinlike drugs on allergen-induced early and late asthmatic responses

Little is known about the anti-asthmatic effects of powerful anti-inflammatory agents such as aspirin-like drugs. We compared the effects of two aspirin-like drugs with different pharmacologic activities, sodium salicylate (SSA) and indomethacin, with the effect of lysine acetylsalicylate (LASA), inhaled 30 min before challenge, on the early and the late asthmatic response induced by a single dose of allergen causing a 25% decrease in FEV1 in a preliminary challenge. Inhaled SSA partially prevented both the early and late response, providing a protection with respect to placebo of 22 +/- 6% in the early phase and 23 +/- 9% in the late phase of the response. These values were lower (but not significantly) than those of LASA (41 +/- 9% and 39 +/- 11%, respectively). In a second group of patients, indomethacin failed to affect the early response, while LASA provided a protection of 31 +/- 7%. However, these two drugs were equally effective in reducing the late response (44 +/- 18% and 39 +/- 17% protection for LASA and indomethacin, respectively). In subjects with an early response, despite being ineffective in preventing allergen-induced bronchoconstriction, indomethacin blocked the allergen-induced increase in bronchial hyperresponsiveness measured 2 h after challenge. We conclude that inhaled salicylates, but not indomethacin, exert a protective activity against the early allergic response. This difference is not explained by the different pattern of cyclooxygenase inhibitory activity of these drugs.

Combined lung volume reduction surgery and thoracic aortic aneurysm resection

Postoperative improvement of respiratory function has been reported with lung volume reduction surgery (LVRS) in patients with severe emphysema. Since smoking is an established risk factor for lung cancer, vascular diseases and emphysema, it is not infrequent to find these diseases associated in the same patient. Combined treatment of lung cancer and emphysema has already been reported. Surgical treatment of vascular diseases in emphysematous patients could also benefit from the application of LVRS techniques. We report resection of an aortic aneurysm combined with LVRS in a patient with concomitant thoracic aortic aneurysm and severe emphysema. Respiratory function improved in the postoperative period.

Protective effect of inhaled lysine acetylsalicylate on allergen-induced early and late asthmatic reactions

Conflicting results have been reported on the effect of non-steroidal antiinflammatory drugs on allergen-induced asthmatic responses. The aim of this study was to investigate the effect of inhaled lysine acetylsalicylate (LASA) on the early and late allergen-induced responses. We studied 16 patients with mild, stable asthma who had an early asthmatic response and 10 patients with a dual (early and late) response. Each patient underwent two challenges with a single dose of allergen assessed in a preliminary test, after inhalation of either 720 mg of LASA in 4 ml of saline solution or placebo, according to a randomized, double-blind protocol. Allergen-induced hyperreactivity to methacholine was measured in six patients from each of the early and the dual response groups 2 hours and 24 hours after the challenge, respectively. In the patients with early response, the maximum fall in FEV1 after challenge was 24% +/- 1% after inhalation of placebo and 14% +/- 2% after inhalation of LASA (p < 0.005). No protection was observed in four patients who received the drug orally instead of by inhalation. In the patients with a dual response, the maximum FEV1 decrease during the early response was 27% +/- 2% after placebo and 21% +/- 2% after LASA (p < 0.025). During the late response (between 3 and 8 hours), the maximum decrease in FEV1 was 28% +/- 4% after placebo and 16% +/- 4% after LASA (p < 0.005). In both groups allergen challenge caused a significant reduction in methacholine PD20 after treatment with placebo but not with LASA. Without allergen challenge, LASA had no effect on methacoline reactivity. We conclude that inhaled LASA significantly reduces both the early and the late asthmatic response to allergen challenge and that it prevents the allergen-induced airway hyperresponsiveness that follows these responses.

Attenuation of aspirin-induced bronchoconstriction by sodium cromoglycate and nedocromil sodium

The protective activity of nedocromil sodium and of sodium cromoglycate against aspirin-induced asthma has never been investigated in controlled studies. Because it has been reported that aspirin-induced platelet-mediated cytotoxic activity in vitro is inhibited after treatment in vivo with nedocromil but not with cromoglycate, we investigated whether these compounds also exhibit a different protective activity against aspirin-induced bronchoconstriction. Ten patients with aspirin-induced asthma underwent three bronchial challenges with a single dose of lysine acetylsalicylate (LASA) that caused a decrease in FEV1 of 25% or more in a preliminary dose-response test 30 min after inhalation of 4 mg nedocromil sodium, 10 mg sodium cromoglycate, or placebo. FEV1 and SRaw were recorded at intervals for 195 min. After placebo, LASA caused a maximal decrease in FEV1 of 42 +/- 4% of baseline. After cromoglycate and nedocromil the maximal decrease in FEV1 was reduced to 20 +/- 3% and 18 +/- 4%, respectively (p < 0.01 versus placebo for both treatments), without significant differences between the two treatments. Similar results were observed with SRaw. We conclude that, at the recommended therapeutic doses, sodium cromoglycate and nedocromil sodium are equally effective in attenuating aspirin-induced bronchoconstriction and that it is unlikely that platelet activation participates in the pathogenesis of aspirin-induced asthma.

Inhaled PGE2 prevents aspirin-induced bronchoconstriction and urinary LTE4 excretion in aspirin-sensitive asthma

Bronchial overproduction of leukotrienes and inhibition of prostaglandin synthesis are involved in the pathogenesis of aspirin-induced asthma. We investigated whether inhaled prostaglandin E2 (PGE2) attenuates the response to bronchial challenge with lysine acetylsalicylate (LASA) and the associated increase in urinary leukotriene E4 (u-LTE4) in seven aspirin-sensitive subjects with asthma. Each subject performed two challenges with a single dose of LASA that caused a decrease in FEV1 of 20% or more in a preliminary test, immediately after inhaling 100 micrograms PGE2 in 4 ml saline or placebo, according to a randomized double-blind protocol. FEV1 was recorded at 30-min intervals for 4 h. u-LTE4 was measured by combined high-performance liquid chromatography enzyme immunoassay at 2-h intervals. After placebo, LASA caused an obstructive reaction in all patients, with a maximum decrease in FEV1 of 35 +/- 5% with respect to baseline. u-LTE4 rose from 911 +/- 261 picograms (pg)/mg creatinine at baseline to a maximum value of 2249 +/- 748 after challenge. Inhaled PGE2 provided almost complete protection in all patients. Baseline u-LTE4 was 883 +/- 243 pg/mg creatinine and did not change significantly during the test, reaching a maximum value of 864 +/- 290 (p < 0.05 versus placebo). These results confirm that PGE2 is highly effective in preventing aspirin-induced asthma and suggest that this effect is mediated by inhibition of sulfidopeptide leukotriene production.

Protective effect of furosemide combined with non-steroidal anti-inflammatory drugs administered by inhalation route on guinea-pigs anaphylaxis model

The exposure of ovalbumin sensitized guinea-pig to an areosol of the specific antigen causes a respiratory crisis in approximately 100 s (dispnoea time) associated with a substantial increase in blood concentration of both histamine (from 27.5 +/- 1.8 ng/ml to 1570 +/- 26 ng/ml; n = 8) and thromboxane B2 (TXB2, from 0.52 +/- 0.03 ng/ml to 18.1 +/- 0.6 ng/ml; n = 8). The aerosol treatment of the animals (20 min) with furosemide (CAS 54-31-9, frusemide, FRU), nimesulide (CAS 51803-78-2, NIM), acetylsalicylic acid (CAS 50-78-2, ASA) and indometacin (CAS 53-86-1, INDO) at the concentrations of 1-3-10 and 30 mg/ml, before ovalbumin challenge, brought about an attenuation of anaphylactic response. The rank order of potency for the prolongation of dyspnoea time was FRU > NIM > ASA > INDO. In these experiments blood evaluation performed at the peak of the dyspnoea time for histamine concentration in the treated animals indicated that whereas FRU (ED25 = 2.14 mg/ml (1.97-2.38) and NIM (ED25 = 2.74 mg/ml (2.37-3.19)) were equiactive in reducing the release of histamine, ASA and INDO were devoid of this activity. On the contrary, the results obtained with ASA and INDO indicated a greater intrinsic activity in antagonizing TXB2 formation than that shown by the log-dose response curves of NIM and FRU. In another series of experiments the interaction of FRU with the other anti-inflammatory drugs in protecting guinea-pig from immune bronchoconstriction has been evaluated using the combination of two equiactive doses. The mixture considered were FRU+NIM, FRU+INDO and FRU+ASA. The results obtained indicated that FRU interacts positively with the three non-steroidal anti-inflammatory drugs in delaying the onset of the dyspnoeic crisis in guinea-pig. However, when FRU was combined with NIM the gain obtained (209%) appeared superior to that reached when FRU was combined with ASA (180%) or INDO (126%). Taken together these results suggest that non-steroidal anti-inflammatory compounds given by aerosol may represent a valid pharmacological intervention in protecting guinea-pig from anaphylactic bronchoconstriction.

Steroid-sparing effect of inhaled lysine acetylsalicylate and furosemide in high-dose beclomethasone-dependent asthma

BACKGROUND

Inhaled lysine acetylsalicylate and furosemide exert a mutually potentiating protective activity on experimentally induced bronchoconstriction in asthma.

OBJECTIVE

Our purpose was to investigate the clinical effectiveness of combined treatment of asthma with inhaled lysine acetylsalicylate and furosemide.

METHODS

We performed a randomized, double-blind, crossover study in nine patients with chronic asthma requiring a high dose (2 mg/day) of inhaled beclomethasone for clinical control. Patients were treated with a combination of 720 mg inhaled lysine acetylsalicylate and 40 mg furosemide twice daily, or with matched placebo in addition to inhaled steroids. The dose of inhaled steroids was reduced by half every 15 days and eventually suspended unless a patient's respiratory condition worsened.

RESULTS

During treatment with placebo, all patients had worsening of asthma at dosages of 1 or 0.5 mg/day beclomethasone (mean +/- SE, 833 +/- 83 micrograms/day). During combined treatment complete suspension of inhaled steroids in two patients and reduction to 0.5 to 0.25 mg in the remaining seven patients (mean, 250 +/- 72 micrograms/day) was achieved, with a mean reduction of 71% +/- 7%. Forced expiratory volume in 1 second, weekly peak expiratory flow rate, symptom score, and bronchodilator intake remained significantly better with combined treatment than with placebo.

CONCLUSIONS

Treatment with inhaled lysine acetylsalicylate and furosemide allows a considerable sparing of inhaled steroids without significant side effects in patients with severe asthma.

The efficacy and safety of moguisteine in comparison with codeine phosphate in patients with chronic cough

We conducted a multicentre, double-blind, parallel group study to compare the clinical efficacy of a new antitussive drug, moguisteine (100 mg t.i.d.), to that of a reference standard, codeine (15 and 30 mg, t.i.d.). Both drugs were given orally for a period of two days. A group of 119 patients (mean age 54 yrs; 61 females and 58 males) with chronic, dry or slightly productive cough, associated with various respiratory disorders (including chronic obstructive pulmonary disease, respiratory malignancies and pulmonary fibrosis) were enrolled at six participating centres. The percentage reduction in the number of morning coughs over a period of 6 h after the first administered dose compared to baseline assessment, was 21% with moguisteine (n = 39), 28% with codeine 15 mg (n = 38), and 29% with codeine 30 mg (n = 36). Differences between treatments were not significant. The percentage reduction in the number of nocturnal coughs per hour, after the last evening dose compared to baseline assessment, was 33, 46 and 52%, respectively. Subjective assessments (patients' visual analogue scale scores of cough frequency, cough intensity and sleep disturbance, and investigators' ranking of cough severity) indicated that there was a similar improvement in cough symptoms in all treatment groups. Adverse events were observed in two patients on moguisteine, three on codeine 15 mg, and five on codeine 30 mg. No event was serious, but discontinuation of treatment was required in two patients on codeine 30 mg. The results of our study suggest that moguisteine 100 mg t.i.d. is safe, and seems to have an antitussive activity similar to that of codeine 15-30 mg t.i.d.

Influence of acetaldehyde on airway resistance and plasma exudation in the guinea-pig

In anaesthetized ventilated guinea-pig, acetaldehyde (CAS 75-07-0) (40-80 mg/kg i.v.) elicits a dose-dependent increase in intratracheal pressure accompanied by an increase in circulating histamine. When acetaldehyde is injected repeatedly at 15 min intervals in capsaicin-desensitized animals, it already loses its activity at the second administration (50% reduction; p < 0.01); this does not happen in control animals. This phenomenon is even more marked when acetaldehyde is given at the dose of 80 mg/kg i.v., since at the third injection both the bronchoconstriction and the increase in blood histamine are almost completely reduced to baseline values. The increase in intratracheal pressure caused by acetaldehyde (20, 40, 80 mg/kg i.v.) is associated with a dose related increase in microvascular permeability and leakage of protein-bound Evans blue in lower tracheal tissue. This event and the bronchoconstrictor response caused by acetaldehyde (40 mg/kg i.v.) are 87% and 35% inhibited, respectively, (p < 0.01) in tachykinin-depleated animals. On the contrary, thiorphan (2 mg/kg i.v.) remarkably potentiates both the rise in intratracheal pressure (110%; p < 0.01) and Evans blue extravasation (215%; p < 0.01) induced by acetaldehyde (20 mg/kg i.v.) in normal guinea-pigs. Furthermore, treatment with CP-96,345, a selective tachykinin NK1-receptor antagonist, only prevents plasma extravasation in lower tracheal tissue (82% inhibition; p < 0.01) without affecting the bronchoconstriction caused by acetaldehyde (40 mg/kg i.v.).(ABSTRACT TRUNCATED AT 250 WORDS)

Time-limited protective effect of inhaled frusemide against aspirin-induced bronchoconstriction in aspirin-sensitive asthmatics

Inhaled frusemide effectively prevents the bronchial obstructive response to allergens and to a number of nonallergic stimuli. In most of the experimental models in which it has been tested, the protective effect of frusemide has been evaluated for only a short time after administration. In aspirin-sensitive patients, acetylsalicylic acid causes an asthmatic reaction which typically lasts for 2 h or more after exposure. We investigated the presence and duration of the protective effect of inhaled frusemide against the bronchial response to aspirin in sensitive patients, using a specific inhalation challenge with lysine acetylsalicylate (LASA). In the first study, eight subjects with aspirin-asthma underwent two bronchial challenges with a single dose of lysine acetylsalicylate administered through a jet nebulizer, after treatment with 40 mg inhaled frusemide or placebo, according to a randomized, double-blind protocol. Forced expiratory volume in one second (FEV1) was monitored for 120 min after challenge. In the second study in eight patients, the protocol was modified by the use of a dosimeter for delivery of lysine acetylsalicylate, by reducing the dose of lysine acetylsalicylate to avoid intense reactions, and by extending the follow-up to 4 h. In the first study, after placebo, FEV1 gradually decreased, reaching a maximum decrement of 39 +/- 3% at 120min. Inhaled frusemide exerted a significant protection at all time-points, although this activity appeared to decrease with time. In the second study, after placebo, inhaled lysine acetylsalicylate caused a gradual decrease in FEV1, which reached a maximum decrement at 180 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Potentiation of the antireactive, antiasthmatic effect of inhaled furosemide by inhaled lysine acetylsalicylate

Nonsteroid antiinflammatory drugs interfere with the diuretic activity of furosemide, implying that this effect is at least partially dependent on renal prostaglandin synthesis. To investigate whether prostaglandin production could also modulate the bronchial antireactive activity of this diuretic drug, we investigated the effect of inhaled lysine acetylsalicylate (162 mg) and of furosemide (18 mg), alone and in combination, on the bronchial obstructive response to ultrasonically nebulized water in asthmatic patients. The study was also prompted by the conflicting results obtained in previous studies of oral nonsteroid antiinflammatory drugs. Fifteen asthmatic patients underwent bronchial challenge with a mist of ultrasonically nebulized distilled water at the same time of day on four occasions, 2-4 days apart, 15 min after premedication according to a double-blind, randomized protocol. After placebo, mean PD15 to water mist did not differ from a preliminary test (2.1 +/- 0.2 and 2.5 +/- 0.4 ml, M +/- SE, respectively). After lysine acetylsalicylate, mean PD15 rose to 5.0 +/- 0.7 ml (2.8 +/- 0.6 times higher than placebo); after furosemide, to 9.0 +/- 1.5 ml (4.4 +/- 0.9 times over placebo); and after the two drugs in combination, to 32.2 +/- 5.6 ml (16.3 +/- 3.0 times higher than placebo). Similar results were obtained with inhaled indomethacin, whereas sodium salicylate had no effect. These data indicate that the bronchial antireactive activity of inhaled furosemide is greatly enhanced by inhaled lysine acetylsalicylate through a mechanism which probably involves inhibition of the local synthesis of prostaglandins, and could have therapeutic implications.

Protective effect of inhaled piretanide on the bronchial obstructive response to ultrasonically nebulized H2O. A dose-response study

Inhaled furosemide prevents the obstructive response to several bronchoconstrictor stimuli in asthma. To verify whether this protective effect is also shared by other loop diuretics, we investigated the effect of inhaled piretanide on the bronchial obstructive response to ultrasonically nebulized distilled water (UNW) in ten patients with moderate, stable asthma. In a randomized, single-blind dose-response study, each subject performed an UNW test immediately after nebulization of different doses of piretanide between 12 and 48 mg or placebo. The effect of a single 40-mg dose of inhaled furosemide was also investigated in six subjects. Piretanide caused a significant, dose-dependent increase in UNW PD20 with respect to placebo, corresponding to 0.6 +/- 0.2 doubling doses (mean +/- SE) after 12 mg, 1.3 +/- 0.2 after 24 mg, and 2.0 +/- 0.2 after 48 mg, and had a remarkable diuretic effect; 40 mg of furosemide increased UNW PD20 by 2.3 +/- 0.3 doubling doses (p < 0.01), but showed only a modest diuretic activity. These data indicate that inhaled piretanide is as effective as furosemide in preventing UNW-induced asthma, and this effect is unrelated to their diuretic potency.

Inhaled loop diuretics as potential new anti-asthmatic drugs

The observation that changes in bronchial osmolarity can induce bronchoconstriction in asthma inspired the experimental studies which, unexpectedly, revealed that frusemide is an effective bronchoprotective agent against a variety of osmotic and non osmotic stimuli. Although the mechanism of this protective effect is not fully understood, studies in vivo and in vitro suggest that frusemide may inhibit the activation of different cell types induced by bronchoconstrictor stimuli. Other loop diuretics also exert bronchoprotective activity, but frusemide appears to be the more effective bronchoprotective agent of this family, regardless of their diuretic potency and lipid solubility. Despite the relatively large amount of experimental evidence, there is currently little information on the clinical effectiveness of frusemide in asthma and a long-term controlled study is currently in progress. The observations that treatment with a combination of inhaled acetylsalicylate and frusemide results in a markedly increased bronchoprotective effect compared to either drug alone, opens a new perspective in the possible clinical use of these drugs. Preliminary studies suggest that the association of these drugs is well tolerated and may result in a remarkable steroid sparing effect in patients with steroid dependent asthma, for whom a convenient alternative to long-term steroid therapy is not currently available.

Efficacy and tolerability of nimesulide in asthmatic patients intolerant to aspirin

Inflammation of the airways accompanied by eosinophil infiltration appears to play a fundamental role in the pathogenesis of bronchial asthma. Therefore, anti-inflammatory agents (at present corticosteroids, cromoglycate and nedocromil) are the first-line treatment for this condition. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin (acetylsalicylic acid) and indomethacin, however, have never been used in this setting, mainly for fear of adverse effects (e.g. severe obstructive reactions); these can occur, in a consistent number of patients as a consequence (according to the most widely accepted theory) of inhibition of prostaglandin synthesis. In a double-blind crossover placebo-controlled study involving 20 aspirin-sensitive patients with asthma, we found that oral nimesulide 100mg was well tolerated both clinically and functionally (no significant changes in forced expiratory volume in 1 second and specific airway resistance after drug intake). In a more recent study, we observed a mild obstructive reaction (easily controlled with inhaled bronchodilators) after oral administration of nimesulide 400mg to 3 patients who had previously tolerated a 100mg dose. On the basis of clinical experience, nimesulide (unlike most other NSAIDs) in the recommended doses appears to be well tolerated in aspirin-sensitive asthmatic patients. Furthermore, this distinctive anti-inflammatory agent might provide a novel approach to the treatment of bronchial asthma.

Inhaled loop diuretics as potential new anti-asthmatic drugs

The observation that changes in bronchial osmolarity can induce bronchoconstriction in asthma inspired the experimental studies which, unexpectedly, revealed that frusemide is an effective bronchoprotective agent against a variety of osmotic and non osmotic stimuli. Although the mechanism of this protective effect is not fully understood, studies in vivo and in vitro suggest that frusemide may inhibit the activation of different cell types induced by bronchoconstrictor stimuli. Other loop diuretics also exert bronchoprotective activity, but frusemide appears to be the more effective bronchoprotective agent of this family, regardless of their diuretic potency and lipid solubility. Despite the relatively large amount of experimental evidence, there is currently little information on the clinical effectiveness of frusemide in asthma and a long-term controlled study is currently in progress. The observations that treatment with a combination of inhaled acetylsalicylate and frusemide results in a markedly increased bronchoprotective effect compared to either drug alone, opens a new perspective in the possible clinical use of these drugs. Preliminary studies suggest that the association of these drugs is well tolerated and may result in a remarkable steroid sparing effect in patients with steroid dependent asthma, for whom a convenient alternative to long-term steroid therapy is not currently available.

Protective activity of inhaled nonsteroidal antiinflammatory drugs on bronchial responsiveness to ultrasonically nebulized water

Relatively high doses of oral aspirin are needed to afford a significant protective effect against the bronchial obstructive reaction to ultrasonically nebulized distilled water (UNDW) in asthmatic patients. Sodium salicylate at similar doses and indomethacin at normal dose afford no protection. The present study was undertaken to assess the protective activity of these drugs taken by inhalation. Thirteen asthmatic patients performed two UNDW challenges 20 minutes and 24 hours after inhalation of 900 mg lysine acetylsalicylate (L-ASA) or placebo. The volume of UNDW causing a 20% fall in FEV1 (UNDW PD20) was calculated by linear interpolation on the dose-response curve. UNDW response after placebo was not significantly different from the preliminary test (PD20 4.3 +/- 0.7 and 4.1 +/- 04 ml, respectively, mean +/- SE), whereas after L-ASA, UNDW PD20 increased to 17 +/- 2.7 ml (p < 0.01 vs placebo) and remained significantly increased after 24 hours. In another group of 12 patients under the same experimental conditions, an equivalent dose of inhaled sodium salicylate caused no effect. Finally, in a third group of asthmatic patients pretreatment with inhaled indomethacin at two dose levels (6 patients, 25 mg; 10 patients, 50 mg) resulted in a significant dose-related protective effect. These findings indicate that inhaled indomethacin and especially L-ASA exert against UNDW-induced bronchoconstriction a potent protective effect, which appears to be mediated by inhibition of local prostaglandin synthesis in the airways. This fact could have therapeutic implications.

Prevention of exercise-induced bronchoconstriction by a new leukotriene antagonist (SK&F 104353). A double-blind study versus disodium cromoglycate and placebo

The effects of 800 micrograms of inhaled SK&F 104353, a peptidoleukotriene receptor antagonist, and of 20 mg disodium cromoglycate (DSCG) on exercise-induced bronchoconstriction were compared in 18 asthmatic patients. The study was conducted according to a double-blind, crossover, randomized, placebo-controlled design. Two baseline exercise tests were carried out, and pulmonary function tests were done before and at 1, 5, 10, 15, 20, and 30 min after completion of the exercise. Patients showing a 20% or greater decrease in FEV1 in both exercise challenges entered the blinded portion of the study. When placebo was administered before exercise, FEV1 fell to the same extent as during the baseline phase. After SK&F 104353 and DSCG, the bronchoconstriction was attenuated. The mean maximal percentage fall in FEV1 after exercise was 29% after placebo and 20% after SK&F 104353 and DSCG. The differences between the two active treatments did not reach the 5% level of statistical significance, though at 20 min SK&F 104353 showed a more pronounced effect than DSCG. The protective effect suggests an important role of leukotrienes in the pathogenesis of exercise-induced bronchoconstriction.

Protective activity of inhaled frusemide against immunological respiratory changes and mediator release in guinea-pigs

The antianaphylactic activity of inhaled frusemide was studied in ovalbumin-sensitized guinea-pigs. The exposure of the animals to frusemide aerosol (1% solution for 20 min) attenuated the respiratory response to ovalbumin challenge (aerosol 1% solution) and was associated with a significant reduction of blood histamine (70%; P less than 0.01) and thromboxane-B2 (35%; P less than 0.01) compared to control animals. Similar results were obtained in isolated lungs perfused via the trachea excised from ovalbumin-sensitized guinea-pigs exposed to frusemide aerosol (1% solution for 20 min). In this series of experiments frusemide significantly prevented the increase in tracheal perfusion pressure (45%; P less than 0.01) and the concomitant release into the pulmonary effluent of both histamine (75%; P less than 0.01) and thromboxane-B2 (39%; P less than 0.01). In another series of experiments, frusemide (1 x 10(-4) M) significantly reduced the immune release of histamine from mast cells of ovalbumin-sensitized rats. The inhibitory activity of frusemide was in the same range of potency (66%; P less than 0.01) as that of disodium cromoglycate (1 x 10(-4) M). These data taken together indicate that frusemide when given by inhalation prevents histamine release secondary to antigen-antibody reaction.

Bronchodilating activity of broxaterol transdermal patch and its protective effect on bronchial constriction induced by inhaled distilled water mist

The bronchodilating activity and the ability of broxaterol transdermal patch to inhibit bronchial constriction in response to distilled water mist (UNH2O) inhalation were assessed. The study was performed in 10 asthmatic patients in clinical remission according to a placebo-controlled, double-blind, randomized crossover design. Test medications were broxaterol patch (size = 1.75 cm2; programmed delivery = 105 mcg/h) and a matched placebo patch. A spirometric examination was performed before patch application (at 8:30-9:00 a.m.) and 24 hours later. Immediately afterwards, the UNH2O inhalation test was made, consisting of 3 bronchial exposures lasting 30, 60 and 120 s respectively with 3-minute intervals between challenges. Immediately after each exposure, a spirometric examination and specific airway resistance measurements were made. The results obtained show that broxaterol patch exerts a statistically significant bronchodilating effect and has a better protective effect than placebo patch on UNH2O-induced bronchial constriction. The local tolerability of patches was very good. Slight tremors were observed in some subjects.

Hyperreactivity and bronchial obstruction

The main obstructive components in bronchial asthma and chronic obstructive pulmonary disease (COPD) are discussed. It is underscored that bronchospasm plays a significant role also in COPD, and that it merits specific treatment (beta 2-stimulants, antimuscarinics, theophylline) even when, in some cases, obstruction appears to be 'irreversible'. The majority of COPD patients react positively, although to a lower degree than asthmatics, not only to chemical agents (histamine, methacholine), but also to 'osmotic' stimuli, such as ultrasonically nebulized distilled water. Geometric factors seem to be in part responsible for the anomalous response. Considering the potent antireactive activity of bronchodilators (beta 2-stimulants in particular), this finding is a further indication for a regular bronchodilator treatment in COPD. Whether such a therapy serves also to improve the prognosis of COPD in the long run has not yet been established.

Antianaphylactic and antihistaminic activity of the non-steroidal anti-inflammatory compound nimesulide in guinea-pig

Nimesulide (4-nitro-2-phenoxymethane sulfonanilide, Aulin, Mesulid) is a non-steroidal anti-inflammatory compound which shows antihistaminic activity and inhibits the immune release of histamine. The antihistaminic activity of this compound is specific for H1-receptor and has been demonstrated on isolated strips of guinea-pig trachea and on histamine-induced multiphasic inotropic response in left atria of guinea pig electrically driven. The effect of nimesulide is of non competitive type and, at the concentration of 1 x 10(-5) mol/l, is nearly 2 time less potent than pyrilamine (mepyramine) at 1 x 10(-6) mol/l. Nimesulide (1.6 mumol/kg i.v.) inhibits both bronchoconstriction (69%) and TXB2 formation (93%) induced by histamine (0.05 mumol/kg i.v.) in anaesthetized guinea-pigs. In contrast indomethacin (1.6 mumol/kg i.v.) decreases the generation of TXB2 (89%) without affecting the enhancement in tracheal insufflation pressure induced by histamine. In actively sensitized guinea-pigs both nimesulide and indomethacin protect the animals from deadly anaphylactic crisis. The rise in tracheal pressure induced by the antigenic challenge is inhibited of 80% and 63% respectively by nimesulide and indomethacin (6.4 mumol/kg i.v.). At this dose the two compounds reduced of 90% approximately the immunological release of TXB2 in the circulation. The release of histamine, induced by the anaphylactic reaction caused in perfused lungs obtained from actively sensitized guinea-pigs, is lessened by nimesulide (EC50 = 3.06; fid. lim. 2.59-3.63 mumol/l) and potentiated by indomethacin (EC50 = 0.89; fid. lim. 0.67-1.17 mumol/l).(ABSTRACT TRUNCATED AT 250 WORDS)

Prevention of antigen-induced early obstructive reaction by inhaled furosemide in (atopic) subjects with asthma and (actively sensitized) guinea pigs

The present study was undertaken to determine the effect of furosemide on antigen-induced bronchoconstriction. Ten patients with stable asthma (eight men and two women), aged 17 to 48 years, were challenged with the same dose of allergen (Dermatophagoides pteronissinus, Parietaria, and grass mix) that had induced an FEV1 fall of at least 20% in a preliminary study on two occasions: immediately after placebo and furosemide (approximately 28 mg) administered by inhalation in random order and double-blind. Furosemide did not demonstrate any direct bronchodilator effect but markedly attenuated allergen-induced bronchoconstriction. The mean (95% confidence interval) maximum fall in FEV1 was 31.5% (40.2% to 22.8%) after placebo and 8.4% (11.8% to 4.9%) after furosemide administration. Furosemide, administered by aerosol to anesthetized guinea pigs actively sensitized to ovalbumin, dose dependently protected the animals from anaphylactic reaction. Infusion of furosemide (10 mg/kg for 10 minutes) failed to protect the animals from the anaphylactic response. In nonsensitized guinea pigs, the cardiovascular and pulmonary changes induced by histamine (10 micrograms/kg intravenously [i.v.]), leukotriene C4 (1 micrograms/kg i.v.), and platelet-activating factor (0.1 microgram/kg i.v.) were not modified by aerosol administration of furosemide (10 mg/ml for 10 minutes). In conclusion, inhaled furosemide induces a clear-cut protection against immediate obstructive reaction caused by areoallergerns and ovalbumin, both in subjects with asthma and actively sensitized guinea pigs, respectively.

Inhaled frusemide is highly effective in preventing ultrasonically nebulised water bronchoconstriction

A decrease in the osmolarity of the periciliary fluid of central airways is supposed to be the initiating mechanism by which ultrasonically nebulised distilled water (UNH2O) induces bronchoconstriction in asthmatics. It is therefore possible that substances, such as frusemide (F), which, in vitro, interfere with ions and water translocation across the tracheo-bronchial epithelium, can also modify such response. To test this hypothesis, 16 adult asthmatics were challenged with UNH2O after being pretreated with either inhaled F (approximately 28 mg delivered into the mouth) or placebo (the diluent) administered in random order and double-blind by means of a jet nebuliser. F did not modify baseline FEV1 and sRaw but attenuated markedly their changes after UNH2O. Mean max % (95% CI) sRaw increases after placebo and F were 293% (168-419) and 63% (21-104), respectively; mean max % falls in FEV1 were 26% (20-32) and 6% (-1-12). Thus inhaled F is highly effective in preventing UNH2O-induced bronchoconstriction and this unexpected property could have therapeutic implications.

Prevention of exercise-induced bronchoconstriction by inhaled frusemide

To determine whether inhaled frusemide, a diuretic able to interfere with ion and water movement across airway epithelium, can modify exercise-induced bronchoconstriction, a three-part randomised, double-blind, placebo-controlled study was done in asthmatic patients who had a fall in FEV1 of at least 20% after running up and down a corridor. In the first part the effect of approximately 28 mg frusemide given as an aerosol was compared with that of a placebo. In the second part two doses of inhaled frusemide (approximately 14 mg and 28 mg) were examined. In the third part the effect of 20 mg oral frusemide was tested. Inhaled frusemide had a good and dose-related protective effect, whereas oral frusemide was ineffective. The mean (95% CI) maximum percentage falls in the FEV1 were: 11.5 (14.3-8.7) with frusemide and 33.8 (39.1-28.5) with placebo in the first part of the study; 13.6 (21.6-6.0) with 28 mg frusemide, 19.7 (28.2-11.3) with 14 mg frusemide, and 34.6 (39.4-30.0) with placebo in the second part of the study; and 15.2 (19.9-10.5) with inhaled frusemide, 38.2 (47.1-29.3) with oral frusemide, and 35.3 (45.9-24.7) with placebo in the last part of the study. The findings lend support to the hyperosmolarity hypothesis of exercise-induced asthma and may have therapeutic implications.

Control of the bronchial tone

The tone of airway smooth muscle is the functional expression of a dynamic equilibrium between various excitatory and inhibitory mechanisms. On the excitatory side, the vagal reflex mechanism, mainly activated by central airway irritant receptors, is the most important. Bronchial epithelium plays a pivotal role in the regulation of the responsiveness of these receptors. Cholinergic responses of the bronchial muscle are mediated by muscarinic (M2) receptors. On the inhibitory side, the main mechanism is the adrenergic one: beta 2-receptors are mainly stimulated by circulating adrenaline. A dense population of beta 2-receptors has recently been observed in bronchial epithelium. Nonadrenergic-noncholinergic mechanisms--both excitatory and inhibitory--participate in the regulation of bronchial motor tone, but their role in man is still to be defined. Nonsteroidal anti-inflammatory drugs do not modify bronchial motor tone; thus, in this respect, at least in physiological conditions, a modulatory function of the prostaglandin system can be excluded. Probably the same applies to leukotrienes, but for a definite answer, specific antagonists are needed.

Intolerance to tartrazine in aspirin-induced asthma: results of a multicenter study

One hundred and fifty-six German, Italian and Polish patients with confirmed aspirin-induced asthma underwent open oral challenges with increasing doses of tartrazine up to 25 mg. All positive challenges were repeated under double-blind conditions. Only 4 of 156 patients (all Polish) had positive reactions in a double-blind test, as evidenced by a fall in FEV1 greater than 25% from baseline and corresponding clinical symptoms. Sixty-five patients who tolerated 25 mg tartrazine well received 50-3,000 mg tartrazine and none showed adverse reactions. Thus, intolerance to tartrazine appears to be rare among Central-European and South-European patients with aspirin-induced asthma, its frequency amounting to about 2.6%.

Evaluation of a new bronchodilating compound (broxaterol) administered as a pressurized aerosol

The bronchodilating activity and the tolerability of a new beta 2-agonist, broxaterol hydrochloride, administered in single doses of 200 and 400 micrograms as pressurized aerosol were studied in 12 adult patients with reversible airway obstruction, taking placebo as a control. A double-blind three-way cross-over design using a series of randomly chosen latin squares was employed. FVC, FEV1, MMEF, heart rate, and blood pressure were measured immediately before and 7.5, 15, 30, 60, 120, 180, and 240 min after each treatment. Our results show that broxaterol is an effective bronchodilating drug with a dose-related activity. The areas under the curves of the changes in FVC, FEV1, and MMEF after the 400 micrograms dose were found to be significantly greater as compared to the 200 micrograms dose. Both broxaterol doses produced significant increases in all the spirometric indices already at the first measurement, i.e., 7.5 min after treatment. Broxaterol 400 micrograms induced significant increases in FVC, FEV1, and MMEF through at least 4 h. The tolerability of the new compound was good.

Prevention of fog-induced bronchospasm by nedocromil sodium

A single dose double-blind crossover study was performed to compare the efficacy of nedocromil sodium (4 mg) and placebo administered from pressurized aerosols against bronchoconstriction induced by the inhalation of ultrasonically nebulized distilled water (fog) in twelve asthmatic subjects. Neither active nor placebo pre-treatment produced any significant change in baseline FEV1 and SRaw. Nedocromil sodium significantly attenuated fog-induced falls in FEV1 (P less than 0.001) and increased specific airways resistance (SRaw, P less than 0.01). The results provide further evidence of the potential therapeutic usefulness of nedocromil sodium in the management of chronic obstructive airways disease.

Prevention of fog-induced bronchospasm by high doses of ipratropium bromide in asthmatics

In 12 adult asymptomatic, relatively stable adult asthmatics the protective effect of 3 doses (200, 1,000 and 2,000 micrograms) of ipratropium bromide against bronchospasm induced by an ultrasonic mist of distilled water was functionally (sRaw, FEV1) assessed. Ipratropium bromide and placebo were administered as an inhalation powder via a special inhaler in random order and under double-blind conditions at the same time on 4 usually consecutive days 90 min prior to the challenge. A considerable protective effect (clearly inferior, in any case, to that previously observed by us with fenoterol) was demonstrated (% protection approximately equal to 50) without any striking difference among the 3 doses. Mouth dryness (dose-related) was the sole complaint in some patients.

Prevention of fog-induced bronchospasm by Duovent and its components (fenoterol, ipratropium bromide) in asthmatics

16 hyperreactive asthmatics were challenged with an ultrasonic mist of H2O at the same time of day on 4 usually consecutive days 2 h after premedication with placebo, fenoterol (200 micrograms), ipratropium bromide (80 micrograms) and Duovent (fenoterol 200 micrograms + ipratropium bromide 80 micrograms), given in random order and double-blind conditions. The challenge test consisted of 3 exposures of 30, 60 and 120 s with 4-min intervals. Specific airway resistance (sRaw) was measured under basal conditions and 1, 2 and 3 min after each exposure. FEV1 was measured under basal conditions and immediately after the last sRaw measurement. Fenoterol afforded a good protection; ipratropium bromide alone was ineffective but enhanced the protective effect of fenoterol when the two drugs were given in combination (Duovent). A similar effect was also observed after a second challenge performed 1 h (9 patients) or 3 h (6 patients) after the first one, which was performed 2 h after premedication.

Tolerance of carprofen in patients with asthma caused by non-steroidal anti-inflammatory drugs

Eight asthmatics with respiratory intolerance to NSAIDs and two subjects (one asthmatic, one healthy) only sensitive (asthma) to pyrazolone drugs were challenged under single-blind conditions with a new NSAID, carprofen. No adverse effects were observed in patients sensitive to pyrazolones. Among the other patients, only three developed considerable bronchial obstruction which was rapidly reversed by inhalation of a beta 2-stimulant (fenoterol: 2 puffs). Two subjects developed nasal obstruction with rhinorrhoea: in conjunction with bronchoconstriction in one patient and alone in the other. In conclusion, acute administration of carprofen in patients with respiratory intolerance to NSAIDs, in contrast to most other NSAIDs, never creates a situation of real danger even though in some patients it may considerably increase nasal and bronchial resistance.

Effect of prostacyclin on antigen induced immediate bronchoconstriction in asthmatic patients

The effect of premedication with inhaled prostacyclin (PGI2) on the allergen induced immediate bronchoconstriction was investigated in 10 asthmatic patients, under single blind conditions, by means of a body plethysmograph. Statistical analysis (Dunnett's test) did not show any significant difference between PGI2 and placebo. The possible meaning of these results is discussed.

Tartrazine and prostaglandin-system

Tartrazine, a dye largely employed for colouring foods, drinks, drugs and cosmetics, induces in some aspirin-sensitive subjects a bronchoconstriction similar to that caused by aspirin and other nonsteroidal anti-inflammatory drugs. The interference of tartrazine on prostaglandin system of guinea pig lungs perfused with arachidonic acid has been studied. This compound is able to inhibit in the same manner the formation both of prostaglandins and of thromboxane A2 acting at the cyclooxygenase level as has already been demonstrated for aspirin and indomethacin. Preliminary experiments on aspirin asthmatic patients treated or not with tartrazine are discussed.