G.K. Crompton

Regular inhaled salbutamol and asthma control: the TRUST randomised trial

BACKGROUND Previous work has suggested that the long-term regular use of inhaled beta2-agonist bronchodilators might lead to a deterioration in asthma control. The aim of TRUST (The Regular Use of Salbutamol Trial) was to study the effects of regular use of inhaled salbutamol, the most widely prescribed bronchodilator in the UK, on the control of asthma. METHODS A randomised, double-blind, placebo-controlled trial was undertaken in 983 patients with asthma being treated at least twice a week with short-acting beta2-agonist, alone or in combination with inhaled steroids (2 mg or less) daily. Patients were aged 18 years and over and were recruited from 115 general practices in the UK. 90% (881) of the patients used inhaled corticosteroid therapy, and all patients continued to use their usual inhaled beta2-agonist for symptomatic relief. Patients were randomised to receive 400 microg salbutamol or matched placebo via a Diskhaler four times per day for 12 months. The primary outcome measure was rate of exacerbations of asthma, with criteria based on data from diary cards completed daily by each patient, treatment with additional corticosteroids, or both. FINDINGS There were no differences in the annual rate, timing, or duration of exacerbations between the two groups. The mean morning peak expiratory flow was similar for the two groups. The mean evening peak expiratory flow (p<0.001) and the diurnal variation (p<0.001) were greater, and the use of rescue bronchodilator was less (p<0.001), in the group receiving regular salbutamol. INTERPRETATION There was no evidence that regular use of inhaled salbutamol 400 microg four times daily for a year increased the exacerbation rate of asthma in the population studied.

Cutaneous vasoconstrictor response to glucocorticoids in asthma

The aim of the study was to find out whether asthma patients whose airways obstruction is sensitive (CS) or resistant (CR) to corticosteroid treatment also differ in their cutaneous vasoconstrictor response to a potent topical glucocorticoid. Corticosteroid resistance was defined by failure of forced expiratory volume in 1 s (FEV1) and peak expiratory flow rate to improve by at least 15% after a 2-week trial of corticosteroids (prednisolone 20 mg daily for 1 week, then 40 mg daily for 1 week) despite more than 15% improvement with inhaled beta agonists. Beclomethasone dipropionate in concentrations of 3 micrograms/ml, 10 micrograms/ml, 30 micrograms/ml, and 100 micrograms/ml was applied to forearm skin; the site was occluded under plastic and the degree of blanching assessed after 18 h. CS asthmatic subjects (n = 31), asthma patients with mild airways obstruction (n = 26), asthma patients taking long-term prednisolone (n = 13), and healthy volunteers showed similar vasoconstrictor responses. In CR asthmatic subjects (n = 15), the response (expressed in terms of either blanching intensity or the proportion of patients showing a positive response) was significantly lower than that in the CS group at concentrations of 3 micrograms/ml (p less than 0.01), 10 micrograms/ml (p less than 0.01), and 30 micrograms/ml (p less than 0.05), but not at 100 micrograms/ml. This resistance to glucocorticoids in the skin, together with reported evidence of glucocorticoid resistance in peripheral blood leucocytes, suggests a general defect in the ability of tissues to respond to glucocorticoids in CR asthma.

Do large volume spacer devices reduce the systemic effects of high dose inhaled corticosteroids

When used in high doses, inhaled corticosteroids may cause suppression of the hypothalamo-pituitary-adrenal axis. The influence of the mode of drug inhalation on the degree of this suppression is not clear. Hypothalamo-pituitary-adrenal function was assessed by measurement of 0900 h serum cortisol concentrations, a short tetracosactrin test, and 24 hour urine free cortisol excretion in 48 adults with asthma taking 1500-2500 micrograms beclomethasone dipropionate daily via a metered dose aerosol. Twelve patients had hypothalamo-pituitary-adrenal suppression, as judged by subnormal results from at least two of the three tests or (in one patient) by an abnormal insulin stress test response. These patients then changed to inhaling the same dose of beclomethasone dipropionate through a 750 ml spacer device (Volumatic). The endocrine tests were repeated from nine days to eight weeks later in 10 patients. Comparison with initial values showed that adding the spacing device caused an increase in the median 0900 h cortisol concentration from 126 nmol/l to 398 nmol/l, in the post-tetracosactrin cortisol concentration from 402 nmol/l to 613 nmol/l and in 24 hour urine free cortisol excretion from 54 nmol to 84 nmol. The rise in serum cortisol concentration in response to tetracosactrin did not change. Evidence of persisting hypothalamo-pituitary-adrenal axis suppression was present in only four of the 10 patients; the most pronounced improvements in function tended to occur in those who had never required long term oral corticosteroids. The results from this uncontrolled study suggest that asthmatic patients taking high dose beclomethasone dipropionate may minimise adverse effects by using a large volume spacer device.

Hypothalamo-pituitary-adrenal axis suppression in asthmatics inhaling high dose corticosteroids

The frequency of hypothalamo-pituitary-adrenal (HPA) axis suppression in asthmatics taking high dose (greater than 1000 micrograms daily) inhaled corticosteroids is unknown. HPA function was studied in 78 adult asthmatics taking long-term inhaled corticosteroids (median dose 1600 micrograms, range 1200-2650 micrograms daily). All patients except one were using metered dose aerosols; 15 were using large volume spacer devices. Median duration of high dose therapy was 13 months (range 1-54). Sixty-nine patients were taking beclomethasone dipropionate (1500 micrograms, n = 36; 2000 micrograms, n = 26, greater than 2000 micrograms, n = 7) and nine budesonide (1200 micrograms, n = 2; 1600 micrograms, n = 6; 1800 micrograms, n = 1). Four patients, all of whom were taking greater than 2000 micrograms beclomethasone dipropionate, were taking 200-400 micrograms of their total dose intranasally. Twenty-six patients had discontinued long term systemic corticosteroid treatment (at least 5 mg prednisolone daily, or equivalent, for a minimum of 6 months) between 7 months and 22 years prior to assessment. All patients had measurements of 9 am serum cortisol and 24-h urine free cortisol excretion and a short tetracosactrin test. Subnormal results were: 9 am cortisol less than 190 nmol l-1; rise in serum cortisol in response to tetracosactrin less than 200 nmol l-1 and/or achieved cortisol less than 500 nmol l-1; urine free cortisol less than 80 nmol 24 h-1. Hypothalamo-pituitary-adrenal suppression was defined as subnormal results in at least two of the three tests. Tests were performed at least 2 weeks after completion of any short course prednisolone treatments. Suppression was found in 16 (20.5%) patients (1500 micrograms, n = 6; 1600 micrograms, n = 1; 2000 micrograms, n = 7; 2400 micrograms, n = 2). Risk factors identified for this suppression were: (a) previous requirement for long-term systemic corticosteroids (10/26, chi 2 = 6.1, P less than 0.02); and (b) increasing duration of high dose inhaled therapy (median 28.5 months in suppressed vs. 12 months in normal, P less than 0.05). No clear relationship was identified between HPA function and dose, even when corrected for body surface area and there was no relationship between suppression and number of short courses of prednisolone in the preceding 12 months. Screening tests of HPA function should be performed in all asthmatics taking greater than or equal to 1500 micrograms inhaled corticosteroid daily. Unless function has been shown to be normal, all patients taking these doses should carry steroid cards.

The ADMIT series — Issues in Inhalation Therapy. 2) Improving technique and clinical effectiveness

Aerosol inhalation is considered the optimal route for administering the majority of drugs for the treatment of obstructive airways diseases. A number of Pressurised Metered-Dose and Dry Powder Inhalers are available for this purpose. However, inhalation of therapeutic aerosols is not without difficulty; it requires precise instructions on the inhalation manoeuvre, which is different from spontaneous normal breathing. Also, the characteristics of the inhaler device have to be suitable for the user. Available data indicate a frequent lack of knowledge demonstrated by health professionals and patients on the inhalation manoeuvre and handling of inhalers, resulting in a reduction of therapeutic benefit. This paper reviews the literature concerning the fundamental aspects of inhaler devices, inhalation manoeuvre and device selection, in an attempt to increase the knowledge of, and to optimise the clinical use of, therapeutic inhalers.

Screening for hypothalamo-pituitary-adrenal axis suppression in asthmatics taking high dose inhaled corticosteroids

High dose inhaled corticosteroids may cause suppression of the hypothalamo-pituitary-adrenal (HPA) axis. Several tests are available to screen for this suppression but it is not clear which is the most useful. HPA function was assessed in 78 adult asthmatics inhaling long-term, high dose (median 1600 micrograms; range 1200-2650 micrograms) beclomethasone dipropionate (n = 69) or budesonide (n = 9). Screening tests performed in all patients were 9 am serum cortisol, short tetracosactrin test and 24-h urine free cortisol excretion. Eleven patients also underwent insulin stress tests. Subnormal results were: 9 am cortisol less than 190 nmol l-1; urine free cortisol less than 80 nmol 24 h-1; rise in cortisol in response to tetracosactrin or hypoglycaemia less than 200 nmol l-1 and/or achieved cortisol less than 500 nmol l-1. HPA suppression (defined as subnormal results of at least two of the three initial tests and/or subnormal response to hypoglycaemia), was found in 16 patients. In the 11 patients who underwent insulin stress tests, results of all initial tests were normal in three, one test was abnormal in three and two tests were abnormal in four patients. All three tests were abnormal in the remaining patient. The response to hypoglycaemia was normal in the three patients whose screening tests were all normal; HPA suppression was present in seven patients and one patient had a borderline result. Close correlation was observed between the maximum cortisol during hypoglycaemia and both urine free cortisol (rs = 0.84; P = 0.001) and post-tetracosactrin cortisol (r = 0.75; P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

The ADMIT series - Issues in Inhalation Therapy. 6) Training tools for inhalation devices

Inhaled medications are the preferred therapies for patients with asthma and COPD, but their effectiveness is limited by the patients ability to use the device properly, an issue often neglected when these medications are prescribed. Correct inhaler technique must be taught and learnt, and requires educational and motivational programs aimed at patients and healthcare providers alike. Written instructions alone are manifestly insufficient: education must include practical demonstration and periodic re-assessment and reeducation, since correct technique and motivation usually deteriorate with time. Several devices are available on the market, the purpose of which is to train patients to use inhalers correctly. They are often directed at particular devices or groups of devices and/or particular critical aspects of technique. This paper reviews the devices currently available for training patients in the correct use of both pressurised metered-dose inhalers (pMDIs) and dry powder inhalers (DPIs).

Systemic effects of high dose inhaled steroids: comparison of beclomethasone dipropionate and budesonide in healthy subjects.

ACKGROUND--Systemic absorption of inhaled corticosteroids may adversely influence the function of the hypothalamo-pituitary-adrenal axis, bone metabolism, and circulating leucocytes. These changes can be used to assess the safety of different types and modes of administration of these drugs. METHODS--The study was a randomised, double dummy, crossover design with nine healthy adults. It compared the effects of beclomethasone dipropionate and budesonide (given by metered dose aerosols with and without their respective large volume spacers (Volumatic and Nebuhaler) attached) on serum cortisol, 24 hour urinary free cortisol, and plasma osteocalcin concentrations, and circulating neutrophils and lymphocytes. Subjects inhaled the drug (1 mg) and matching placebo at 0900 and 2200 hours on each of six study days. Blood samples were taken hourly for six hours after the morning dose and at the end of the study period. RESULTS--All results were within the reference ranges. Both drugs caused similar reductions in serum cortisol four to six hours after inhalation. These changes were not affected by the use of a large spacer and did not persist at 24 hours. Use of spacers tended to increase the haematological effects of the steroids. Beclomethasone dipropionate inhaled through a Volumatic provoked a rise in circulating neutrophils compared with placebo although lymphocyte numbers were unaffected. Budesonide did not influence neutrophil numbers but did reduce circulating lymphocytes, numbers of which were further reduced when the Nebuhaler was used. There were no significant changes in plasma osteocalcin concentration or 24 hour urinary free cortisol excretion with budesonide, with or without a spacer. Beclomethasone dipropionate inhaled without a spacer reduced urinary cortisol and plasma osteocalcin at 24 hours; however, use of the Volumatic protected against these effects. CONCLUSIONS--Attaching a Volumatic reduces the systemic effects of 2 mg aerosol beclomethasone dipropionate on the hypothalamo-pituitary-adrenal axis and circulating osteocalcin concentrations. This study did not establish whether the Nebuhaler reduces the systemic effects of budesonide. When large spacers are used, 2 mg per day of beclomethasone dipropionate and budesonide seem to be equivalent in terms of unwanted effects.

The ADMIT series – Issues in Inhalation Therapy. 5) Inhaler selection in children with asthma

Many children with asthma do not use their inhalers correctly and consequently gain little or no therapeutic benefit from the treatment. The focus of inhalation therapy should be on those inhalers which are easiest to use correctly by various groups of children and the amount of tuition and training required to obtain a correct technique. It is recommended that clinicians focus on a limited number of inhalers. Most children can be taught effective inhalation therapy by using a pMDI, a pMDI with a spacer ,or a DPI. Most preschool children can be taught effective use of a pMDI and spacer with a valve system and a face mask. Therefore, this is the preferred mode of delivery in these age groups. When the child is capable of using the spacer without a face mask this administration technique should be adopted. In older children pMDIs are more difficult to use correctly than a pMDI with a spacer, a DPI ,or a breath-actuated pMDI. Because DPIs and breath-actuated pMDIs are more convenient to use these devices are normally considered the preferred inhalation devices in these age groups except for administration of beclometasone dipropionate, which for safety reasons should be delivered by a spacer.

THE USE OF ELECTRONIC DIARIES IN RESPIRATORY STUDIES

Background—Electronic diary cards have advantages over paper diaries for daily collection of data on lung function and symptoms in patients with respiratory disorders. The suitability of a pen-based electronic diary (Apple MessagePad) for this purpose was assessed in a clinical trial setting. Methods—Two studies were carried out in patients with chronic obstructive airways disease: 1. An open randomized two-period crossover study comparing electronic and paper diaries in 22 clinic outpatients aged 18–70. Data were collected for four weeks on each type of diary, and 2. An open study in 37 patients in general practice aged 13–80. Data were collected for four weeks on electronic diaries only. Results—In Study 1, 59% of patients preferred the electronic diary and 18% preferred paper. Both paper and electronic diaries were found to be easy to use. There were fewer problematic data from the electronic diaries (0.24% of data points) compared with paper (5.6%), resulting in improved data reliability. There were more missing data, however, with electronic diaries (8.9% vs 0.2%; p = 0.0001) which probably relates to the fact that the electronic diary did not permit retrospective entry. Data handling procedures were greatly simplified for the electronic diaries. Problems occurred with battery life and power management. Study 2 confirmed the acceptability of electronic diaries in this patient group, and showed no battery problems using a later model of the hardware (MP 110). Conclusions—Pen-based electronic diaries are acceptable to patients, and offer major benefits in terms of data reliability and simplification of data handling.