Asthma treatment and growth

Benefit versus risk for oral, inhaled, and nasal glucocorticosteroids

Many factors affect the benefit-to-risk analysis of the use of the glucocorticosteroids in the treatment of allergic inflammation. For most patients the benefit-to-risk ratio favors topical over oral administration, but in severe disease oral administration may be required. It is clear from pharmacokinetic and pharmacodynamic studies that inhaled glucocorticosteroids in particular are absorbed into the systemic circulation and that they can have clinical adverse effects when given in high doses. Therefore, with inhaled and nasal glucocorticosteroids, the dose that will achieve the optimal benefit/risk ratio is the lowest dose that controls symptoms and prevents exacerbations requiring treatment with oral glucocorticosteroids. This optimal dose needs to be determined on an individual basis and is likely to vary as disease severity changes over time.

Effects of inhaled corticosteroids on bone

OBJECTIVE

To discuss the effects of inhaled corticosteroids on bone and their potential public health implications.

DATA SOURCES

The MEDLINE and EMBASE databases were searched to identify articles published between 1966 and January 2004 with the following keywords in the title: inhaled corticosteroid, beclomethasone, budesonide, flunisolide, fluticasone, mometasone, triamcinolone plus bone, fracture, osteoporosis, osteocalcin, growth, or height.

STUDY SELECTION

Key studies of adequate size and duration that allowed for potential confounding factors where required were selected.

RESULTS

Inhaled corticosteroids are absorbed into the systemic circulation and therefore have the potential to cause adverse effects on bone. Several of the larger studies showed that inhaled corticosteroids cause a dose-related reduction in bone mineral density. Three cross-sectional studies found a dose-related increase in fractures in people taking an inhaled corticosteroid compared with controls. Prospective studies found a short-term reduction in growth velocity in children taking an inhaled corticosteroid, although target adult height is usually achieved.

CONCLUSION

Since osteoporotic fracture is common in elderly patients and up to 5% of the population in more developed countries take an inhaled corticosteroid, these findings have public health implications. Strategies are needed to reduce the systemic effects of inhaled corticosteroids.

Nutrition in patients with cystic fibrosis: a European Consensus

This document is the result of an European Consensus conference which took place in Artimino, Tuscany, Italy, in March 2001 involving 33 experts on nutrition in patients with cystic fibrosis, organised by the European Cystic Fibrosis Society, and sponsored by Axcan-Scandipharm, Baxter, Dr Falk Pharma, Fresenius, Nutricia, SHS International, Solvay Pharmaceuticals (major sponsor). The purpose of the conference was to develop a consensus document on nutrition in patients with cystic fibrosis based on current evidence.

Treatment of childhood asthma: how do the available options compare?

The National Asthma Council of Australia suggests that "the aim of preventive therapy should be to enable patients to enjoy a normal life (comparable with that of non-asthmatic children), with the least amount of medication and at minimal risk of adverse events. The level of maintenance therapy should be determined by symptom control and lung function in the interval periods." The British Thoracic Society/Scottish Intercollegiate Guidelines Network states that the aims of the pharmacological treatment of asthma should be to control symptoms, prevent exacerbations and achieve the best possible lung function with minimal adverse effects. We have used the current published international guidelines to highlight the international differences in management recommendations, and compared the possible pharmacological options with a focus on the above ideals. Cromones have been used for many years in childhood asthma. Most evidence suggests they now have little role. Regarding inhaled corticosteroids (ICS), beclomethasone and budesonide are essentially similar in their efficacy. Fluticasone propionate is equally as effective at one-half the equivalent dose of budesonide or beclomethasone. Adverse effects are rare in dosages <400 microg/day of budesonide and beclomethasone or <200 microg/day of fluticasone propionate, but may occur in individual patients. Relevant clinical adverse effects are rare and pharmacological systemic effects are less noticeable with budesonide and fluticasone propionate than with beclomethasone, but data are conflicting. Long-acting beta2-adrenoceptor agonists (beta2-agonists) are recommended once low-dose ICS have failed to control symptoms. The main pharmacological difference between the agents is that formoterol is a full beta2-adrenergic agonist, whereas salmeterol is a partial agonist at the beta2-adrenoceptor and has a unique pharmacological action. The main clinical distinction between these two agents is that their onset of bronchodilation differs. Bronchodilation begins at about 3 minutes after inhalation of formoterol, which is similar to the short-acting agents, whereas salmeterol has a much slower onset of action at about 15-30 minutes. The many in vitro differences between the two drugs are probably not clinically relevant. There are no comparative pediatric data on the leukotriene modifiers to make clear recommendations.

Safety of the newer inhaled corticosteroids in childhood asthma

Inhaled corticosteroids (ICS) remain a vital part of the management of persistent asthma, but concerns have been raised about their potential adverse effects in children. This review examines the safety data on three new ICS - fluticasone propionate, mometasone, and extrafine beclomethasone in hydrofluoroalkane (HFA-134a) propellant (QVAR The use of tradenames is for product identification purposes only and does not imply endorsement. formulation) in relation to the older corticosteroids. Topical adverse effects such as thrush and dysphonia are rare, but dental erosion is a possibility with powder forms of ICS because of their low pH. Thus, it is important to stress mouth rinsing after administration and maintaining good dental hygiene to minimize this risk. Biochemical adrenal suppression can be readily demonstrated, particularly with high doses of all ICS. The clinical relevance of this was uncertain in the past, but there have now been >50 reported cases of acute adrenal crises in children receiving ICS, most of whom were on fluticasone propionate. In order to minimize the risk of symptomatic adrenal suppression, it is important to back-titrate the ICS dose and alert families of children receiving high-dose ICS of this potential adverse effect. A pediatric endocrine opinion should be sought if adrenal suppression is suspected. The older ICS cause temporary slowing of growth velocity, but the limited data available do not show any significant compromise of final adult height. The effect on growth of fluticasone propionate may not be as great as with the older ICS, but the studies have been short term and only used low doses of fluticasone propionate. There have been case reports of growth suppression in children receiving high doses of fluticasone propionate. The limited studies performed on the effect of ICS on bone mineral density in children did not show any adverse effects, but there may be an increased risk of fractures. Hydrofluoroalkane beclomethasone (QVAR) is essentially the same drug as chlorofluorocarbon beclomethasone, but with double the lung deposition owing to the smaller particle size. Thus, it could be expected that any adverse effects seen with chlorofluorocarbon beclomethasone would be the same with hydrofluoroalkane beclomethasone. However, some of the published data, particularly in adults, suggest that hydrofluoroalkane beclomethasone may be less systemically active than chlorofluorocarbon beclomethasone, even at equipotent doses. As yet, there are no long-term data on mometasone, but initial studies in adults suggest there may be less suppression of the hypothalamic-pituitary-adrenal axis, although further studies are required, particularly in children.ICS will remain a cornerstone in the management of persistent pediatric asthma, provided that the diagnosis of asthma is secure. It is very important to use ICS appropriately and to ensure the lowest possible doses are used to achieve symptom control, thus minimizing the risk of serious adverse effects.

Fluticasone and beclometasone: what are their effects on children's growth?

Fear of growth retardation may account for the underuse of inhaled corticosteroids in children with asthma, despite compelling evidence of their effectiveness. This fear may be reduced with newer agents with lower oral bioavailability if their theoretical advantage of fewer systemic adverse effects than the standard treatment of inhaled beclometasone is realized in practice. This review aims to determine if one of the newer agents, inhaled fluticasone, has less effect on the growth of pre-pubertal asthmatic children than inhaled beclometasone. The outcome measure was growth velocity. Two double blind, randomized controlled trials were identified. In one of the studies the mean growth velocity in the fluticasone group was 0.7 cm/year greater than in the beclometasone group. In the second, smaller study the mean growth velocity in the fluticasone group was 0.8 cm/year greater. There is therefore some evidence that fluticasone has less (if any) adverse effect on growth.

Delayed puberty in chronic illness

Delayed puberty can be defined as the lack of pubertal development at an age of 2 SD above the mean, which corresponds to an age of approximately 14 years for males and 13 years for females, taking both sex and ethnic origin into consideration. Its incidence associated with chronic illnesses is unknown; however, its clinical importance is relevant due to the larger percentage of patients with chronic disorders surviving until the age of puberty. Virtually every child with any chronic disease could present with delayed puberty (due to recurrent infections, immunodeficiency, gastrointestinal disease, renal disturbances, respiratory illnesses, chronic anaemia, endocrine disease, eating disorders, exercise and a number of miscellaneous abnormalities). Pubertal delay associated with chronic illness is accompanied by a delay in growth and the pubertal growth spurt. The degree to which growth and pubertal development are affected in chronic illness depends upon the type of disease and individual factors, as well as on the age at illness onset, its duration and severity. The earlier its onset and the longer and more severe the illness, the greater the repercussions on growth and pubertal development. The mechanism that trigger the start of physiological puberty remain unknown. Although malnutrition is probably the most important mechanism responsible for delayed puberty, emotional deprivation, toxic substances, stress and the side effects of chronic therapy, among others, have been implicated in the pathophysiology of delayed puberty. Therefore, early diagnosis is essential and appropriate and specific therapy fundamental.

A randomised controlled trial of short term growth and collagen turnover in asthmatics treated with inhaled formoterol and budesonide

AIMS

To determine effects on short term growth and collagen turnover of adding formoterol (Eformoterol) to half the glucocorticoid dose in children with asthma, treated with inhaled budesonide (Pulmicort Turbuhaler).

DESIGN

A randomised double blind, placebo controlled crossover study with two six-week periods.

SETTING

Outpatient clinic in secondary referral centre.

SUBJECTS

A total of 27 prepubertal children aged 6-13 years.

INTERVENTIONS

Formoterol 12 microg and dry powder budesonide 100 microg twice daily in one period; placebo and dry powder budesonide 200 microg twice daily in the other.

OUTCOME MEASURES

Primary outcome measures were lower leg growth rate, and serum and urine markers of type I and type III collagen turnover. Secondary outcome measures were inflammation markers in serum, and parameters of asthma control.

RESULTS

During budesonide 200 microg twice daily treatment, mean lower leg growth rate was 0.14 mm/week (p = 0.02) lower than during the formoterol and budesonide period. Similar statistically significant effects on markers of collagen turnover were found, whereas inflammation markers and asthma control did not vary statistically significantly between the two periods.

CONCLUSIONS

In children treated with inhaled glucocorticoids, halving the dose and adding formoterol is associated with faster short term growth and an increase in markers of collagen turnover, with no loss of asthma control.

Treatment of childhood asthma. Options and rationale for inhaled therapy

Epidemiological studies suggest the prevalence of asthma is increasing, though some remain sceptical as to the magnitude or indeed the presence of an increase. However, despite improved diagnosis and the availability of the potent drugs now available there remains considerable respiratory morbidity associated with asthma. It is clear from a number of studies that failure to deliver drugs to the lungs when using inhaler devices is a factor contributing to this high level of morbidity. Failure of drug delivery may result from the prescribing of inappropriate devices, failure to use devices appropriately or failure to comply with a treatment regimen. For most of the currently available forms of asthma therapy there are significant advantages to be gained from administering them in aerosol form. The benefits to be derived from administering these drugs as an aerosol include a rapid onset of action for drugs such as beta-agonists and a low incidence of systemic effects from drugs such as beta-agonists and corticosteroids. Over the past 25 years our understanding of the nature of asthma has changed. Though this has been reflected in the emphasis on inhaled corticosteroid therapy in recent guidelines, it has not been reflected in the range of inhaler devices available. Manufacturers continue to place drugs such as corticosteroids in the same devices as short acting beta-agonists even though the requirements for these different drug classes are very different. It is likely that this contributes to suboptimal therapeutic responses with inhaled corticosteroids. However, the variability associated with current delivery systems is relatively small compared with the variability introduced by poor compliance. There is no work currently available to indicate how the use of cheap disposable devises which do not incorporate any form of positive feedback influence compliance with inhaled steroids. Optimising aerosolised drug delivery in childhood involves consideration of the class of drugs, the particular drug within a class but more importantly, the age and abilities of the child. Devices must be selected to suit a particular child's needs and abilities. Devices utilising tidal breathing are generally used such as spacing chambers or, less commonly these days, nebulisers. A screaming or struggling child, or failure to use a closely fitting mask, reduces drug delivery to the lungs enormously. Failure to respond to inhaled therapy in early childhood may be attributable to failure of drug delivery. Drug delivery in early childhood using current devices remains more an art than a science.