The T/QRS ratio values in pregnancies complicated by threatened preterm labour treated with intravenous infusions of fenoterol

AIMS

To evaluate values of foetal T/QRS ratios in pregnancies complicated by threatened preterm labour treated with intravenous infusions of fenoterol using non-invasive methods with transabdominal electrodes.

MATERIALS AND METHODS

The study group consisted of 451 Caucasian women (63 preterm pregnancies and 327 healthy controls) whose pregnancies ranged from 28 to 37 gestational weeks. Foetal electrocardiograms were recorded and T/QRS ratios were calculated by KOMPOREL software (ITAM, Zabrze, Poland). The first recording was performed 30 min after the start of fenoterol infusion and the second 2 days after finishing tocolysis. T/QRS ratio variables were calculated. One-way analysis of variance was carried out.

RESULTS

Significantly higher mean values of the T/QRS ratio were observed in pregnancies during tocolytic treatment in comparison to controls and pregnancies after tocolysis (P=0.0158 and P=0.0071, respectively). The T/QRS ratio values fall again shortly after finishing intravenous tocolysis.

CONCLUSIONS

The T/QRS ratio is one of the methods used for non-invasive foetal distress assessment that can be used in antepartum foetal monitoring in complicated pregnancies. Raised values of the T/QRS ratio in the foetus during tocolysis with fenoterol and next its fall to values observed in physiological pregnancies may indicate transient worsening of fetal well-being, however, additional research is required.

[Right ventricular hypertrophic cardiomyopathy in the fetus --may it be caused by chronic oral tocolysis with fenoterol?]

The use of fenoterol in the treatment of preterm labor is associated with the risk of many complications in the mother and the fetus. We present a case of a multipara treated with oral fenoterol due to threatening preterm labor 14 weeks. At 35 weeks of gestation the fetus was diagnosed with hypertrophic cardiomyopathy with severe impairment of the right ventricle. The only factor that might have caused such a state of the fetal circulatory system was fenoterol, used from 21 weeks of gestation. After the withdrawal of the fenoterol the fetal right ventricular function improved gradually. However fetal cardiac hypertrophy persisted until the birth at 39 weeks of gestation. Concentric hypertrophy of the right ventricular wall and interventricular septum were confirmed in the newborn.

Fenoterol did not enhance glucocorticoid-induced skeletal changes in male rats

Glucocorticoids and β(2)-adrenergic receptor agonists are the most commonly used drugs in the treatment of asthma. Both therapies are potentially dangerous to the skeletal system. The aim of the present study was to investigate the effects of fenoterol, a β(2)-receptor agonist, on the development of bone changes induced by glucocorticoid (prednisolone) administration in mature male rats. The experiments were carried out on 24-week-old male Wistar rats. The effects of prednisolone 21-hemisuccinate sodium salt (7 mg/kg s.c. daily) or/and fenoterol hydrobromide (1.4 mg/kg i.p. daily), administered for 4 weeks, on the skeletal system were studied. Bone turnover markers, geometric parameters, mass, mass of bone mineral in the tibia, femur and L-4 vertebra, bone histomorphometric parameters and mechanical properties of tibial metaphysis, femoral diaphysis and femoral neck were determined. Both prednisolone and fenoterol had damaging effects on the skeletal system of mature male rats. However, concurrent administration of fenoterol and prednisolone did not result in the intensification of the deleterious skeletal effect of either drug administered separately.

Tocolysis and delayed delivery versus emergency delivery in cases of non-reassuring fetal status during labor

AIM

To determine whether fetal intrauterine resuscitation using tocolysis and delayed delivery is better for the fetus than emergency delivery when fetal hypoxia is suspected because of a non-reassuring fetal heart-rate (FHR) pattern using conventional heart rate monitoring.

METHODS

This was a prospective and randomized study, conducted between 2001 and 2004 at Pereira Rossell Hospital, Montevideo, Uruguay. The population consisted of 390 fetuses, in which intrauterine distress was diagnosed using electronic FHR monitoring. Of these, 197 were randomly assigned to the emergency delivery group and 193 to the fetal intrauterine resuscitation group. The inclusion criteria were: term singleton pregnancy, in labor, cephalic presentation, and no placental accidents.

RESULTS

The time between randomization and birth was 16.9 +/- 7.6 min (mean +/- SD) for the emergency delivery group, and 34.5 +/- 11.7 min (mean +/- SD) for the resuscitation group. The relative risk (RR) of acidosis in the umbilical artery (pH < 7.1) in the emergency delivery group was 1.47 (0.95-2.27). The RR of base deficit < or =12 mEq/L in the emergency delivery group was higher than in the resuscitation group (RR = 1.48 [1.0-2.2], P = 0.04). When considering the need for admission to the neonatal care unit, the relative risk was higher in the emergency delivery group than in the resuscitation group (RR = 2.14 [1.23.3.74], P = 0.005). No maternal adverse effects were reported.

CONCLUSION

Tocolysis and delayed delivery renders better immediate neonatal results than emergency delivery when fetal distress is suspected because of a non-reassuring fetal heart pattern. In addition, it may decrease the need for emergency delivery without increasing maternal and fetal adverse side-effects.

Myocardial ischemia induced by nebulized fenoterol for severe childhood asthma

We examined for myocardial ischemia induced by continuous inhalation of fenoterol in children with severe acute asthma. Thirty children with severe acute asthma were evaluated for signs of myocardial ischemia when treated with 0.5 mg kg dose (maximum 15 mg) of inhaled fenoterol for one hour. The heart rate was measured before and after inhalation. Cardiac enzymes (creatine kinase, creatine kinase MB fraction and troponin levels) were measured at admission and 12 hours later. An EKG was recorded before inhalation was started and immediately after its completion to detect the presence of any evidence of myocardial ischemia. All patients developed significant increase in heart rate. Six patients showed EKG changes compatible with myocardial ischemia, despite normal enzyme levels. Patients with severe acute asthma show tachycardia and may show EKG changes of myocardial ischemia.

Short-acting inhaled beta-2-agonists increased the mortality from chronic obstructive pulmonary disease in observational designs

OBJECTIVE

The effect of short-acting inhaled beta(2)-agonists on mortality from chronic obstructive pulmonary disease (COPD) is controversial. Different observational designs were used to investigate about this topic.

STUDY DESIGN AND SETTING

A population-based case-control design was performed, by linking automated health databases from the Varese Province of Italy. Deaths of COPD generated from the cohort of 135,871 patients for whom at least one prescription for drugs used to treat COPD had been dispensed between 1997 and 1999 entered into the study as cases. Up to 20 controls were randomly selected for each case from the cohort after matching on gender, age, and date of cohort entry. Risk ratios were estimated using the case-control, case-crossover, and case-time-control approaches.

RESULTS

A total of 222 cases and 3022 controls met the inclusion criteria. Odds ratios (and corresponding 95% confidence intervals) corresponding to more than 0.5 defined-daily-doses were 2.6 (1.7, 4.0), 1.9 (1.1, 3.3), 2.1 (1.1, 4.0), and 2.3 (1.2, 4.6) by using crude and adjusted case-control, case-crossover, and case-time-control estimates, respectively.

CONCLUSION

Evidence that higher doses of short-acting inhaled beta(2)-agonists are associated with higher mortality from COPD was consistently supplied by three observational approaches.

A review of ipratropium bromide/fenoterol hydrobromide (Berodual) delivered via Respimat Soft Mist Inhaler in patients with asthma and chronic obstructive pulmonary disease

Asthma and chronic obstructive pulmonary disease (COPD) can be effectively treated by the use of bronchodilator therapies delivered by inhalation. Berodual is a fixed combination of the anticholinergic agent ipratropium bromide (IB) and the beta2-adrenergic agonist fenoterol hydrobromide (FEN). IB/FEN has been available for the treatment of asthma and COPD in a pressurised metered dose inhaler (MDI) [pMDI] formulation for many years. The pMDI is the most widely used device for the delivery of inhaled medications, such as IB/FEN. However, most conventional pMDIs contain chlorofluorocarbon (CFC) propellants, which are currently being withdrawn because of their detrimental effects on the environment. This has resulted in alternative methods of drug delivery being developed. Respimat Soft Mist Inhaler (SMI) is a new generation, propellant-free inhaler that generates a fine, slow-moving cloud (the Soft Mist) which can be easily inhaled. Scintigraphic studies have shown that this improves deposition of drugs in the lung and results in less oropharyngeal deposition than the CFC-MDI. A clinical development programme has been conducted to compare the efficacy and safety of IB/FEN delivered via Respimat SMI with that of IB/FEN via CFC-MDI in the treatment of patients with asthma or COPD. Five clinical studies (two phase II and three phase III) investigated dosages of IB/FEN 5/12.5 microg to 320/800 microg via Respimat SMI in single and multiple dose administration regimens. Four of the trials were conducted in patients with asthma (three in adults and one in children), while one phase III trial was conducted in patients with COPD. In phase III, 2058 patients participated, with a total of 1112 patients treated with IB/FEN via Respimat SMI. In the phase III studies, each dose from Respimat SMI was given in one actuation compared with two actuations with the CFC-MDI. In the paediatric asthma phase III study, all CFC-MDI doses were delivered via a spacer device. The results of the trials demonstrated that IB/FEN via Respimat SMI allows a reduction in the nominal dose of IB/FEN, while offering similar therapeutic efficacy and safety to a CFC-MDI. In children, Respimat SMI obviates the need for a spacer.

Efficacy and safety of ipratropium bromide plus fenoterol inhaled via Respimat Soft Mist Inhaler vs. a conventional metered dose inhaler plus spacer in children with asthma

The objective of this study was to compare the efficacy and safety of ipratropium bromide/fenoterol hydrobromide (IB/FEN; Berodual) delivered from the novel propellant-free Respimat Soft Mist Inhaler (SMI) with that from a chlorofluorocarbon (CFC) metered-dose inhaler (MDI) plus spacer in children with asthma. The study followed a multicenter, randomized, double-blind (within Respimat SMI), parallel-group design. During the 2-week run-in period, patients received two actuations of CFC-MDI tid (IB 20 microg/FEN 50 microg per actuation) via a spacer (Aerochamber) (MDI 40/100). Patients (n=535) were then randomized to: Respimat SMI containing IB 10 microg/FEN 25 microg (Respimat SMI 10/25), IB 20 microg/FEN 50 microg (Respimat SMI 20/50), one actuation tid or CFC-MDI containing IB 20 microg/FEN 50 microg per actuation (in total 1B 40 microg/FEN 100 microg), or two actuations tid via Aerochamber (MDI 40/100), for 4 weeks. The primary endpoint was the change in forced expiratory volume in 1 second (FEV1) during the first 60 min after dosing (area under the curve from 0-1 h [AUC(0-1 h)]) on day 29. Analysis of the primary endpoint demonstrated that the efficacy of Respimat SMI 10/25 and 20/50 was equivalent to or greater than that of MDI 40/100. Similar results indicating that Respimat SMI 10/25 and 20/50 were not inferior to MDI 40/100 were also found on days 1 and 15. Analyses of other secondary endpoints supported these results. The safety profile of Respimat SMI was comparable to that of the CFC-MDI plus spacer. In conclusion, IB/FEN delivered via Respimat SMI is at least as effective as, and is as safe as, when delivered via CFC-MDI plus Aerochamber in children with asthma. Use of Respimat SMI thus enables a 2-4-fold reduction in the nominal dose of IB/FEN, and obviates the need for a spacer.

[Comparison of the cost of treatment of premature labor with atosiban or beta-sympathomimetics from the perspective of the health care payer--a pharmacoeconomic model]

OBJECTIVE

To evaluate the cost of treating premature delivery with atosiban or beta-sympatomimetic drugs (fenoterol and hexoprenalin) from the perspective of health care payer--the medical insurance company.

DESIGN

A pharmaco-economic model based on the results of randomized, controlled clinical study.

SETTING

Hospital Pharmacy at Vitkovice Hospital of Blessed Mary Antonia, Ostrava.

METHODS

The study is based on the application of clinical decision-making analysis, which includes results of a randomized controlled clinical study as well as data on the cost of clinical interventions and cost of drug therapy. The pharmaco-economic model was created from the perspective of the payer of health care--the insurance company. This model presumes the administration of atosiban or beta-sympatomimetic drugs (fenoterol and hexoprenalin) for the period of 18 and 48 h and the therapy of possible untoward effects for the next 72 h after the administration of the drugs. The analysis of sensitivity of pharmacokinetic model also employs so called low and high estimate of supplementary cost for the treatment of untoward effects.

RESULTS

After the administration of the drugs for the period of 18 h the total cost of the payer of medical care was in the range of 21,914.5-21,974.4 CKr in atosiban, 19,878.7-22,661.4 CKr in fenoterol and 19,942.9-21,974.4 CKr in hexoprenalin. In the administration of the drugs for 48 h, the overall cost of the payer of medical care was in the range of 43,082.5-43,142.4 CKr in atosiban, 19,960.3-23,150.7 CKr in fenoterol and 20,131.3-23,574.0 in hexoprenalin.

CONCLUSIONS

This study compared overall cost associated with hospitalization of a premature delivery from the perspective of the medical care payer, i.e. the health insurance company. The authors applied a pharmaco-economic model evaluating hospitalization for the period of 48 h and subsequent therapy of possible untoward effects for the period of up to 72 h. In case of a shorter administration of atosiban (up to 18 h) the overall cost of hospitalization for premature delivery for the period of 48 h from the point of view of medical insurance company is basically comparable with the administration of beta-sympatomimetic drugs. If atosiban is administered for more than 18 h, the overall cost of hospitalization is higher than with beta-sympatomimetic drugs, and the cost increases in relation to the duration of atosiban administration.

[Effect of high doses of broncholytics on the state of cardiovascular system during treatment of sever exacerbation of bronchial asthma]

The use of broncholytic drugs through nebulizer is a standard treatment for acute episodes of bronchial asthma. However doses of these drugs administered by nebulizer can be much higher than those applied when metered dose inhaler is used. These doses have a potential of cardiotoxic effects.

MATERIAL

Patients (n=75) with severe exacerbation of bronchial asthma.

METHODS

All patients received broncholytic drugs through nebulizer. Doses were adjusted according to age and concomitant pathology among which prevailed ischemic heart disease (21.3%) and hypertension (53.3%). Nebulized beclomethasone was an alternative to systemic corticosteroids. Safety of therapy was controlled with electrocardiography, 24-hour electrocardiography, measurements of serum potassium level, registration of subjective signs (palpitation, tremor) and objective data (heart rate, blood pressure).

RESULTS

Clinical improvement occurred in all patients. By the end of nebulizer therapy arterial blood O(2) saturation increased 4.66% from initial level (p=0.04). Peak expiratory rate and forced expiratory volume in 1 sec also rose (p <0.05). Termination of nebulizer therapy was associated with decrease of number of both supraventricular and ventricular premature beats. Moderate widening of of QT interval above 460 ms was registered in 4 patients, 3 of whom had ischemic heart disease. There were no significant changes of serum potassium levels.

CONCLUSION

Broncholytic drugs administered by nebulizer in therapeutic doses selected with consideration of age and concomitant diseases did not produce cardiotoxic effects.

Fenoterol delivery by Respimat soft mist inhaler versus CFC metered dose inhaler: cumulative dose-response study in asthma patients

OBJECTIVES

Respimat (RMT) soft mist inhaler (SMI) is a novel, propellant-free alternative to chlorofluorocarbon metered-dose inhalers (CFC-MDIs). The aim of this study was to evaluate the safety and establish the equipotent dose of fenoterol delivered by RMT SMI vs. a conventional MDI.

DESIGN

Double-blind, randomized, crossover, comparative study between fenoterol inhaled via RMT (either 50 microg/actuation, RMT50; or 100 microg/actuation. RMT100) and MDI (100 microg/actuation; MDI100).

PATIENTS AND INTERVENTIONS

A total of 41 asthma patients received cumulative doses of fenoterol 600 microg (RMT50) or 1200 microg (RMT100 and MDI100) on 3 test days.

MEASUREMENTS AND RESULTS

The bronchodilator response (forced expiratory volume in 1 second [FEV1]) was considered therapeutically equivalent (i.e., noninferior) if the 95% confidence intervals for the difference in their mean changes from baseline were within limits of +/- 0.15L. Systemic exposure was evaluated from plasma fenoterol levels. Adverse events (AEs) were recorded. RMT50 and RMT100 produced noninferior bronchodilatation to MDI100 from 30minutes after the first dose. RMT50 showed equivalent safety and tolerability to MDI100, whereas RMT100 produced a higher incidence of AEs, a significantly greater plasma potassium reduction and a significant increase in pulse rate. Fenoterol plasma levels were twice as high with RMT100 as with RMT50 or MDI100. CONCLUSIONS; The nominal dose of fenoterol administered via RMT SMI can be at least halved to achieve equivalent efficacy, safety, and tolerability to a MDI.

Supraventricular tachycardia after fenoterol inhalation: report of two cases

Supraventricular tachycardia (SVT) following fenoterol inhalation in metered-dose inhaler (MDI) has never been reported. We report two cases of SVT after fenoterol inhalation in MDI. Case one was a 4-year-old boy who had asthma since early childhood. Paroxysmal supraventricular tachycardia (PSVT) was found after fenoterol inhalation (MDI), which returned to normal sinus rhythm following adenosine injection. The other one was a 9-year-old male who also had asthma since early childhood. He suffered from attacks of PSVT four times after fenoterol inhalation within one year. After verapamil injection and vagal maneuvers, PSVT was converted to normal sinus rhythm. There were no other episodes of SVT after discontinuing usage of fenoterol inhalation for 2 years in the follow-up. We report these two cases to remind pediatricians that cardiac arrhythmias should be evaluated following fenoterol inhalation (MDI).

[Cerebral hemorrhage and periventricular leucomalacia in preterm neonates after intravenous tocolysis with fenoterol: results of postnatal ultrasound examination]

BACKGROUND

This study tested whether tocolysis with beta-adrenergic agonists (Fenoterol) had an effect on the frequency of cerebral lesions in preterm neonates.

PATIENTS AND METHODS

Head ultrasound scans of preterm neonates who were born after long-term (> 24 h) tocolysis were compared with scans of preterm neonates without preceding tocolysis. The gestational and neonatal data were analyzed retrospectively.

RESULTS

Preterm neonates after (n = 102) and without (n = 101) tocolysis were subdivided into three groups according to their gestational age (23 - 28 wk: n = 41; 29 - 33 wk: n = 66; 34 - 36 wk: n = 96). Within these groups, no significant differences were found with respect to birth weight, rate of cesarean section, or pulmonary morbidity. Preterm babies < 28 weeks of gestation from the control group had lower Apgar scores (after 1 and 5 minutes, respectively) and arterial umbilical cord pH values. Intravenous tocolysis did not lead to an increase in pseudocystic periventricular leucomalacia (PVL) or intracerebral hemorrhage (ICH) in any of the subgroups studies. However, cerebral lesions were found in preterm neonates after tocolysis who exhibited signs of infection (29 - 33 wk: PVL n = 2; 23 - 28 wk: ICH n = 1) and in preterm neonates without tocolysis who had undergone fetal hypoxia or abruptio placentae (29 - 33 wk: PVL n = 4; antenatal terminal vein bleeding n = 1; 23 - 28 wk: PVL n = 2; terminal vein bleeding n = 5; posterior cerebral artery bleeding n = 1). When compared to preterm neonates of 34 - 36 weeks of gestation, the risk of infection was increased 4-fold in neonates of 29 - 33 weeks of gestation (odds ratio 5.43, 1.10 - 26.83) and 10-fold in neonates of 23 - 28 weeks of gestation (odds ratio 20.50, 3.65 - 115.03). Chorioamnionitis also was a more common finding in preterm neonates < 28 weeks of gestation.

CONCLUSION

Preterm neonates who were born after intravenous long-term (> 24 h) tocolysis with Fenoterol do not exhibit an increase in periventricular leucomalacia or intracranial hemorrhage. The occurrence of cerebral lesions in these patients merely depends on their degree of immaturity and on the presence or absence of perinatal infection. In preterm neonates without tocolysis, brain lesions are mainly associated with hypoxic events.

Maternal and fetal side effects of tocolysis using transdermal nitroglycerin or intravenous fenoterol combined with magnesium sulfate

OBJECTIVE

To compare the maternal and fetal side effects of transdermal nitroglycerin and intravenous fenoterol combined with magnesium sulfate in a prospective randomised study.

STUDY DESIGN

Fifty pregnant women between 27 and 35 weeks of gestation with preterm labour were treated with either nitroglycerin (0.4-0.8 mg/h) or fenoterol (60 - 120 microg/h). Outcome parameters were (1) the effects on fetal and maternal heart frequency (FHF/MHF) and blood pressure, and (2) subjective experiences of adverse effects assessed by utilising a questionnaire.

RESULTS

In the fenoterol group, elevated mean MHF, FHF and systolic blood pressure were recorded compared to nitroglycerin. Fewer maternal side effects were reported in the nitroglycerin group. Palpitations (82%), tremor (68%) and restlessness (64%) were most common in the fenoterol group (two drop-outs), whereas nitroglycerin caused headaches in 71% of the cases (four drop-outs).

CONCLUSION

Transdermal nitroglycerin appears to be a safe therapy for the mother and fetus and is a promising new option for the treatment of preterm labour.

A comparison of terbutaline and fenoterol unit dose vials in treating children with acute asthmatic attacks

To compare the bronchodilation and adverse effects of two commercially marketed short-acting beta2-adrenergic agonists, terbutaline (Bricanyl, 5.0 mg/2ml) and fenoterol (Berotec,1.25 mg/2ml) unit dose vials (UDV), 108 acute asthmatic children, aged 5 to 14, were randomly enrolled into this study. Nebulization treatment for 10 minutes using an air compressor nebulizer was performed after measurements of baseline spirometry, SaO2, blood pressure and pulse rate. Same measurements were repeated at 0, 5, 15 and 30 minutes after the end of the nebulization treatment. The blood pressure was also monitored immediately and 30 minutes after treatment. Almost all the spirometric parameters of both treatments at various time points significantly improved. The pulse rate significantly increased at 15 and 30 min. The SaO2 significantly increased at 30 min. The systolic blood pressure significantly decreased immediately (terbutaline only) and at 30 min (fenoterol only). No significant change was found in diastolic blood pressure. When the laboratory parameters at the same time points were compared. Significant better results for fenoterol treatment were found in FEV, at 30 min (p = 0.048), PEF at 15 and 30 min (p = 0.049 and p = 0.027, respectively), FEF25-75% at 30 min (p = 0.033), mean absolute increase of PEF at 15 min (p = 0.034) and 30 min (p = 0.021), FEF25-75% at 30 min (p = 0.046), and in mean percent increase of FEF25-75% at 30 min (p = 0.047). The adverse effects for both groups were almost equal and around 21%. In conclusion, both terbutaline and fenoterol UDV nebulization treatments are effective in treating acute asthmatic children. The adverse effects are nearly equal. The fenoterol UDV nebulization treatment shows a little better result in improving pulmonary function than does terbutaline.

[Nitroglycerin patch for tocolysis--a prospective randomized comparison with fenoterol by infusion]

OBJECTIVE

To evaluate tocolytic efficacy of transdermal glyceryl trinitrate (GTN) in comparison to fenoterol per infusionem in a prospective randomized multicenter study.

PATIENTS AND METHODS

50 pregnant women between 27 and 35 weeks of gestation with preterm labour were treated with either GTN patches (0.4-0.8 mg/h) or fenoterol per infusionem (60-120 micrograms/h) up to stop of contractions or 35 weeks in maximum. The primary outcomes were the prolongation of gestation by 48 h, 7 days or up to 37 weeks of gestation as well as the neonatal outcome. The progression of cervical ripening and maternal side effects during tocolysis were assessed as secondary outcome criteria.

RESULTS

There was no difference in successful tocolysis for 48 h and 7 days in both groups, whereas significantly more women passed 37 weeks after GTN therapy. So mean duration of pregnancy, birth weight and height were greater, whereas transfer into neonatal care unit was significantly rare after GTN. There were no differences in neonatal outcome and progression of cervical ripening during tocolysis. Maternal side effects during GTN were fewer and weaker compared with fenoterol. Circa 70% of GTN treated women had a headache temporary, whereas more than 90% of the patients with fenoterol suffered from tachycardia and tremor.

CONCLUSIONS

Tocolytic efficacy of transdermal GTN was at least equivalent to the established beta-mimetic therapy with fenoterol. Because of the lower preterm delivery rate transfer into neonatal care for control was significantly rarer after GTN with equally good neonatal outcome in both groups. Beside the headache transdermal GTN therapy had lower maternal side effects in comparison to fenoterol.

Rise and fall of asthma-related mortality in Italy and sales of beta2-agonists, 1980-1994

We performed this study with the aims of describing the trend of asthma-related mortality in Italy between 1980 and 1994, and to evaluate the relationship between sale estimates of beta2-agonists drugs and mortality from asthma. For asthma mortality we used data provided by National Institute of Statistics, for sale estimates of beta2-agonists we used data provided by IMS HEALTH. We calculated the gender specific age-standardized incidence rates of asthma-related deaths for all ages and for age classes. We found that estimates for asthma-related mortality steadily increased between 1980 and 1987 in both sexes, and thereafter decreased. In people, aged between 34 and 64 and over 64, death rates in males were significantly higher than in females while the rates in those aged less than 34, were mostly similar in both gender. The overall exposure to beta2-agonists (alone and in combination) increased from 1980 to 1990, remained stable between 1990 and 1993, and increased steeply in 1994. We conclude that asthma-related death rates have declined since the mid-1980's. This decline has been more pronounced in males and in the older ages, while the rates in younger patients of both genders have remained nearly unchanged. Our data do not substantiate the hypothesis of an increased risk of asthma-related mortality associated to the use of inhaled beta2-agonists in general nor fenoterol or salbutamol in particular.

[Comparative evaluation of efficiency and tolerance of two alternative methods for premature uterine contractions suppression using fenoterol and nitroglycerin]

In the Obstetrics and Gynaecological Department of the National Research Institute of Mother and Child between January 1998 and December 1998, sixty women with premature uterine contractions were treated. 30 women were treated using transdermal nitroglicerin (Nitroderm) and 30 using Fenoterol. There was no difference between age, parity and gestational age at the beginning of this study. The authors compared the efficiency, tolerance and safety of transdermal nitroglicerin and beta-mimetics used for premature uterine contraction suppression. The frequency and intensity of adverse effects were also evaluated.

Beta-adrenergic agonists and bronchial hyperreactivity: role of beta2-adrenergic and tachykinin neurokinin-2 receptors

BACKGROUND

beta(2)-Adrenergic agonists are the most widely used bronchodilators for the treatment of asthma. On the other hand, there is concern that excessive use of beta(2)-agonists may contribute to the exacerbation of asthma. However, the mechanism of such adverse effects of beta(2)-agonists is not completely clear.

OBJECTIVE

The aim of this study was to assess the direct influence of beta(2)-agonists on airways by analyzing the effect of a beta(2)-agonist, fenoterol, on airway sensitivity in an animal model and on tachykinin neurokinin-2 receptor expression in bovine tracheal smooth muscle.

METHODS

We performed an acetylcholine challenge test on ovalbumin sensitized guinea pigs that were exposed to daily inhalation of ovalbumin and fenoterol. We also investigated the effects of fenoterol on neurokinin-2 receptor messenger RNA and density with Northern blot analysis and receptor binding assay.

RESULT

The increase of airway responsiveness and the decrease of beta(2)-adrenergic receptors were found in guinea pigs that were treated with fenoterol. There were time- and dose-dependent increases of neurokinin-2 receptor mRNA and of density in tracheal smooth muscle that was treated with fenoterol.

CONCLUSION

This increased airway responsiveness, increased neurokinin-2 receptor expression, and decreased beta(2)-adrenergic receptor density may be relevant to asthma exacerbation.

Reducing adverse effects of inhaled fenoterol through optimization of the aerosol formulation

We compared the adverse effects of 160 micrograms of fenoterol in the form of a 2.8-micron monodisperse aerosol with those of 800 micrograms of fenoterol as a conventional metered dose inhaler (MDI) aerosol plus spacer. Previously, a monodisperse aerosol was shown to elicit equivalent degrees of bronchodilation at an 80% lower dose using a standard MDI. A total of 12 healthy volunteers (8 women and 4 men) participated in this study and inhaled in random order a placebo, the monodisperse aerosol, and the MDI aerosol. Changes in serum potassium level, finger tremor, blood pressure, heart rate, and specific airway conductance were measured before and 15 minutes after administration. Compared with placebo, the active aerosols elicited a significant improvement in airway conductance and adverse effects. Serum potassium level decreased by 0.27 mmol/L after the monodisperse aerosol, and the MDI lowered it by 0.67 mmol/L (P = 0.001). Finger tremor also increased less: 0.07 versus 0.29 V (P = 0.029). Changes in cardiovascular parameters were not significantly different from those elicited by the placebo. There were no significant specific airway conductance differences between the two active aerosols. By changing the formulation of MDI aerosols, the occurrence of adverse effects can be reduced.

Pulsatile vs. continuous parenteral tocolysis: comparison of side effects

Bolus tocolysis has been developed to reduce the dose of fenoterol compared to continuous tocolysis. Whereas the high efficacy of pulsatile application of fenoterol has been shown, the proof of reduced side effects is still lacking. A total of 59 patients with preterm labor were divided in three groups: (1) continuous tocolysis and oral application of magnesium (n=19), (2) continuous tocolysis and parenteral application of magnesium (n=20), (3) pulsatile tocolysis (bolus tocolysis) and oral application of magnesium (n=20). Heart rate, systolic and diastolic blood pressure, serum K+ and serum Mg++ were quantified before tocolysis and after 2, 8 and 24 h. Beta-blockers and water balance were recorded over 24 h. Subjective side effects were quantified using a questionnaire with scales graduated covering palpitations, tremor, diaphoresis, thirst, precardialgia and nausea/vomiting. The analysis of the data revealed significantly fewer side effects concerning heart rate, plasma K+ level and the subjective side effects among patients treated with bolus tocolysis than among those treated with continuous tocolysis. Between the latter two groups, no significant difference was found. Concerning blood pressure and need for beta-blockers, no significant differences were found between the three groups. The results of the present study show that especially the side effects subjectively found to be disagreeable by the patients are reduced by pulsatile tocolysis, whereas other side effects show only slight differences between the study groups.

Cardiac troponin T in pregnant women having intravenous tocolytic therapy

We studied drug-induced cardiotoxic effects in 22 pregnant women having tocolysis with intravenous fenoterol and verapamil. Because CK-MB is released from the uterus and placenta, we used the determination of cardiac troponin T (cTnT) as it is one of the most sensitive and specific indicators of myocardial necrosis. Cardiac troponin T levels were within physiological range (0.08 +/- 0.01 microgram/l) in all healthy pregnant women tested between 32 and 36 weeks of gestation (control group). In the pregnant women having tocolysis cTnT levels started to increase slightly during the first day of treatment (0.10 +/- 0.03 microgram/l) and were significantly higher (p < 0.05) during the third day (0.35 +/- 0.14 microgram/l) of tocolytic therapy. The cTnT levels in cord blood (0.13 +/- 0.03 microgram/l) did not correspond with maternal cTnT concentrations.

[Effect of continuous intravenous tocolysis with beta 2-mimetics and magnesium sulfate on erythropoietin level]

14 pregnant women receiving continuous intravenous tocolysis for threatened miscarriage were studied for an effect of beta 2-mimetics on erythropoiesis in humans. After tocolytic therapy for 48 h, the hematokrit fell by 14%; conversely erythropoietin levels rose by 88.7%. Increased erythropoiesis was reflected in increased reticulocyte (and reticulocyte subpopulation) counts. There was a significant correlation between cumulative tocolytic dose and erythropoietin elevation at 48 h. The hypervolemia evidenced by the decreased hematocrit was due to the increased oral fluid intake and fluid retention, and was the presumed main cause of the elevated erythropoietin levels. This effect could enhance understanding of the control of erythropoietin secretion. A similar mechanism may account for the increase in erythropoietin levels in pregnancy.

[What dosage is sufficient in combined inhalation therapy (fenoterol + ipratropium bromide) in patients with exacerbation of chronic obstructive lung disease?]

The authors compared in a prospective study the bronchodilatating and undesirable effects of combined inhalation treatment (phenoterol + ipratropium bromide) in the treatment of patients with exacerbation of chronic obstructive pulmonary disease, using different dosages. The patients were divided at random into two groups--group one inhaled berodual sol 3.5 ml/day (i.e. 1.75 mg phenoteroli + 0.875 mg ipratropii bromidium), the second group had a dose of double size. During the trial the authors monitored the peak expiration rate, the heart and respiration rate, blood gases and the subjective state of dyspnoea, using a 10 cm line. By comparison of bronchodilatating and undesirable effects they reached the conclusion that a daily dose of 3.5 ml berodual sol. is sufficiently effective. Increasing the daily dose to 7 ml did not produce a greater therapeutic effect nor increase the risk of undesirable effects.

[Tocolysis with a nitroglycerin patch]

We would like to present a 22 year old nullipara where preterm labor was successfully tocolysed using a nitro-glycerine path without sequellae side effects. Potential advantages and disadvantages of a transdermal nitro-glycerine delivery system in comparison to the commonly used intravenous fenoterol tocolysis is discussed.

Case-control study of salmeterol and near-fatal attacks of asthma

BACKGROUND

A case-control study was undertaken to investigate the hypothesis that the use of the long acting beta agonist salmeterol increases the risk of a near-fatal attack of asthma.

METHODS

The cases comprised admissions to the intensive care unit (ICU) for asthma in 14 major hospitals within the Wessex region in 1992. For each of the cases four age-matched controls were selected from asthma admissions to the same hospital during the same period. Information on prescribed drug therapy for the 48 cases and 185 controls was collected from the hospital admission records.

RESULTS

The patients admitted to the ICU had greater chronic asthma severity and had generally been prescribed more asthma drugs than the control admissions to hospital. The relative risk of a near-fatal attack of asthma in patients prescribed inhaled salmeterol was 2.32 (95% CI 1.05 to 5.16), p = 0.04. However, the salmeterol relative risk decreased to 1.42 (95% CI 0.49 to 4.10), p = 0.52 when the analysis was restricted to the more chronically severe patients (those in the subgroup of patients with a hospital admission for asthma in the previous 12 months). These findings suggest that the increased unadjusted relative risk with salmeterol is predominantly due to confounding by severity--that is, the increased relative risk is due to patients with more severe asthma (at greatest risk of a near-fatal asthma attack) being preferentially prescribed salmeterol. This interpretation is supported by the finding in this study that, within the control group (selected from the population of asthmatics requiring hospital admission), salmeterol was preferentially prescribed to the most severe patients (a threefold greater prescription of salmeterol to control patients if they had been admitted to hospital in the 12 months prior to the index admission). There was no increased risk of a near-fatal attack of asthma in patients prescribed a beta agonist by metered dose inhaler (OR 0.75 (95% CI 0.31 to 1.78), p = 0.51). In contrast, the relative risks for beta agonists delivered by nebulisation (OR 3.86 (95% CI 1.99 to 7.50), p < 0.001) and oral theophylline (OR 2.45 (95% CI 1.26 to 4.78), p < 0.01) were increased and did not markedly decrease when the analysis was restricted to the more severe asthmatic subjects.

CONCLUSIONS

Although these findings are not conclusive, particularly because of the small numbers involved in some subgroup analyses, they suggest that the use of salmeterol by patients with chronic severe asthma is not associated with a significantly increased risk of a near-fatal attack of asthma. If a near-fatal asthma attack is considered to be an intermediate step in a process by which a severe attack of asthma may become fatal, these results would suggest that salmeterol is unlikely to be associated with an increased risk of death, at least by this mechanism.

Optical illusions from visual data analysis: example of the New Zealand asthma mortality epidemic

The abundance of health-related statistics routinely collected worldwide invites their misuse from haphazard associations between secular trends of these data. This misuse is often compounded by assessing these associations simply on the basis of a visual inspection of the data. The visual approach to data analysis, known to have several pitfalls, is particularly tempting in the context of asthma where it has often been used. For example, the epidemic of asthma deaths that occurred in New Zealand during the last two decades has been imputed to fenoterol, a medication for asthma, on the basis of a visual assessment of ecological data. The simultaneity of time trends in the asthma death rate and fenoterol market share in that country formed an important part of the statistical basis of the evidence. We verified whether the results of such visual analyses are corroborated by more objective quantitative statistical methods of analysis. We reanalyzed these same data, namely the time trend data of New Zealand asthma death rates, fenoterol market share, sales of beta-agonists and inhaled corticosteroids, measured yearly for the 16-year span 1976-1991, using Poisson weighted loglinear regression. We found that the protective effect of inhaled corticosteroids (rate ratio 0.5 per canister per month; 95% confidence interval 0.4 to 0.7; p = 0.0001) was more closely associated with changes in asthma mortality than either fenoterol (RR 2.7 per canister per month; 95% CI: 0.9 to 7.5; p = 0.06) or all beta-agonists combined (RR 1.6; 95% CI: 0.8 to 3.0; p = .19). We conclude from this quantitative analysis that these ecological asthma mortality data provide evidence of a stronger association with inhaled corticosteroids, little used in New Zealand at the onset of the epidemic but used abundantly at its termination, than with fenoterol. This conclusion is diametrically opposite to that found by the visual approach. The quantitative analysis demonstrates that the visual approach to the analysis of ecological data, although seemingly convincing, can be misleading by creating an optical illusion. This purely visual approach to data analysis may thus have serious implications when the resulting scientific information is used to make vital public health and policy decisions.

International trends in sales of inhaled fenoterol, all inhaled beta-agonists, and asthma mortality, 1970-1992

To evaluate the hypothesis that fenoterol or all inhaled beta-agonists caused an epidemic of asthma mortality in New Zealand from the late 1970s to the mid-1980s, we examined trends from 1970 to 1992 in per capita sales of inhaled fenoterol, inhaled beta-agonists, and asthma mortality in New Zealand and nine other countries that marketed fenoterol. During the last two decades, there has been a large and widespread increase in sales of inhaled beta-agonists, including fenoterol. Asthma mortality in most countries, however, has been relatively stable. Only New Zealand experienced an epidemic of asthma mortality. In addition, sales rates of fenoterol similar in magnitude to those in New Zealand near the peak of the epidemic also occurred in Belgium, Austria, and Germany, while asthma mortality in these countries remained low. Also, sales rates of all beta-agonists in Australia were similar to those in New Zealand, but no epidemic of asthma mortality occurred in Australia. Therefore, the difference between asthma mortality rates in New Zealand and other countries is not explained by differences in per capita sales of fenoterol or all beta-agonists. Within New Zealand, the beginning and end of the epidemic correlated with a rise and fall in sales of all beta-agonists, including fenoterol. From 1980 to 1989, however, sales of fenoterol and all beta-agonists doubled in New Zealand while asthma mortality declined by 40%. International data on medication sales and asthma mortality, therefore, do not point to a relation between asthma mortality and beta-agonists in general nor fenoterol in particular.

Hypokalaemia in pregnant women treated with the beta 2-mimetic drug fenoterol--a concentration and time dependent effect

The effect of tocolytic treatment with fenoterol on plasma potassium concentrations was studied in 83 pregnant women on intravenous tocolytic therapy. Plasma concentrations of fenoterol and potassium were measured simultaneously, the time interval between initiation of therapy and taking the blood sample varying from 2 hours to 100 days. In a subset of 13 patients this blood sample was taken after two hours of therapy and pretreatment potassium concentrations were measured also. Pretreatment potassium concentrations were normal in these 13 patients and declined to 2.88 mmol/L (median) fenoterol concentrations being 320 ng/L through 1164 ng/L. Potassium concentrations measured later than 24 hours after initiation of therapy were all in the normal range corresponding fenoterol concentrations varying from 200 ng/L to 2504 ng/L. The multivariate statistical model for the description of all data showed that the duration of treatment was the only variable which explained the data to a significant extent. This might indicate that tolerance to the potassium lowering effect of fenoterol had developed within 24 hours after initiation of therapy. In the subset of 13 patients pretreatment potassium concentrations were found to be more important in explaining potassium concentrations than fenoterol concentrations at two hours. As we did not observe any adverse events in patients with low potassium concentrations and potassium concentrations were normal within 24 hours, we conclude that hypokalaemia due to fenoterol in the treatment of premature labor is not of clinical concern.

Therapeutic equivalence of a novel HFA134a-containing metered-dose inhaler and the conventional CFC inhaler (Berodual) for the delivery of a fixed combination of fenoterol/ipratropium bromide. A randomized double-blind placebo-controlled crossover study in patients with asthma

The efficacy and safety of a novel fenoterol/ipratropium bromide metered-dose inhaler (MDI) formulated with a non-chlorinated propellant, HFA134a, has been compared with placebo and the conventional chlorofluorocarbon (CFC)-containing fenoterol/ipratropium bromide inhaler (Berodual) in asthmatic patients. Fifty-two patients were enrolled in two centres. The fenoterol/ ipratropium bromide treatment produced significantly (P < 0.0001) greater bronchodilatation than placebo. There were no significant differences between the mean peak and average forced expiratory volume in the first second (FEV1) for patients receiving 2 puffs of the fenoterol/ipratropium bromide HFA134a inhaler and the conventional CFC inhaler. In addition, time to onset and duration of efficacy were comparable for these two treatments. None of the patients showed a fall of > or = 15% in baseline FEV1 or needed rescue medication within 30 min after inhalation of the test drug. No paradoxical bronchoconstriction was observed as measured by sGaw. The two inhaler formulations were well tolerated. A taste-related complaint, lasting for a few minutes after inhalation, was reported by a higher proportion of patients who inhaled the HFA134a formulation, mainly by patients selected in one of the two centres. In conclusion, a dose of 100 micrograms fenoterol/40 micrograms ipratropium bromide inhaled from a MDI containing HFA134a propellant is safe and provides effective bronchodilatation of equivalent degree, onset and duration of action to the same dose from the conventional CFC formulation.

Confounding by indication and channeling over time: the risks of beta 2-agonists

A previously published nested case-control study, the Saskatchewan Asthma Epidemiologic Project (SAEP) spanning 1980-1987, investigated the risk of fatal or near fatal asthma and found different risks for two inhaled beta 2-agonists, fenoterol and salbutamol. The authors assessed whether this comparison was confounded by indication because of channeling of inhaled fenoterol to more severely afflicted asthmatics. Using three subcohorts selected from a cohort of 12,301 asthmatics assembled from the computerized databases of Saskatchewan Health and followed over 7 years, the authors studied two forms of channeling and investigated whether greater asthma severity and less well-controlled disease were associated with preferential prescribing of a first prescription of inhaled fenoterol, as opposed to inhaled salbutamol, and whether they were associated with the likelihood of a switch from inhaled salbutamol to fenoterol as well as a switch from inhaled fenoterol to salbutamol. The authors found that the initial choice between fenoterol and salbutamol was independent of the severity of the asthma and disease control, but that preferential prescribing of fenoterol occurred among users of salbutamol who showed signs of increased severity or uncontrolled asthma. The switch from inhaled fenoterol to salbutamol was, however, minimally related to asthma severity. They conclude that the comparison between inhaled fenoterol and salbutamol in the SAEP may have been biased by indication. This study demonstrates that long-term information on medication use is essential to ensure that the results of such case-control studies are not biased by indication.

[Long-term effects of inhaled beta 2-agonists on bronchial hyperresponsiveness in asthmatics]

We examined the effects of two year's treatment of three inhaled beta 2-agonists (beta 2), such as salbutamol (S), procaterol (P) and fenoterol (F) on acetylcholine induced bronchial hyperresponsiveness (BHR) in mild approximately moderate asthmatics. When symptomatic use of beta 2 were less than 6 puffs/day, BHR was improved significantly with both S and P but was not with F. When more than 6 puffs/day, all three beta 2 did not show the improvement of BHR. Without the effect of corticosteroids, BHR was improved with S, and was partially improved with P in case of only less than 6 puffs/day, but was not improved with F unrelated to the inhaled puff number. Therefore, frequent use of beta 2 even if used only on demand was shown to worse BHR, asthmatics must be controlled to under the good condition of using beta 2 at least less than 6 puffs/day.