Adrenal responses to low dose synthetic ACTH (Synacthen) in children receiving high dose inhaled fluticasone

Long-Term Usage of Oral Glucocorticoids Leading to Adrenal Insufficiency: A Comprehensive Review of the Literature

Systemic glucocorticoid therapy is used worldwide by one to three percent of the general population and 0.5-1.8% on long-term oral glucocorticoid use. It is widely used in conditions such as inflammation, autoimmune diseases, and cancer to inhibit inflammatory responses. One of the possible undesirable side effects of exogenous corticosteroid treatment is adrenal suppression upon discontinuation of the medication and adrenal insufficiency after utilizing the supraphysiologic doses for more than one month. To prevent patients from the unwanted signs and symptoms of adrenal insufficiency, including fatigue, gastrointestinal upset, anorexia/weight loss, etc., better management of the quantity and frequency of exogenous corticosteroid use, as well as better education before starting its use, is needed. For patients actively on exogenous corticosteroids, a close follow-up must be in place to avoid adrenal suppression after the eventual discontinuation of their use. This review article summarizes the important studies to date on this subject, especially oral glucocorticoid use, and analyzes risks such as dose, duration of exposure, and comorbidities of adrenal insufficiency associated with oral glucocorticoid use. We comprehensively include information on those with primary adrenal insufficiency and pediatric patients, hoping to provide better insight and clinical reference.

Platelet-derived growth factor D expression in adrenal cells is modulated by corticosteroids: putative role in adrenal suppression

BACKGROUND

Adrenal suppression is a clinically concerning side effect of inhaled corticosteroid (ICS) treatment in patients with asthma. Increased susceptibility to ICS-induced adrenal suppression has previously been identified in those with the rs591118 polymorphism in platelet-derived growth factor D (PDGFD). The mechanism underpinning this relationship is not known.

METHODS

H295R cells were genotyped for rs591118 using a validated Taqman PCR allelic discrimination assay. H295R cell viability was determined after treatment with beclometasone and fluticasone (range 0-330 μM). Cortisol was measured in cell culture medium using competitive enzyme immunoassay.

RESULTS

PDGFD protein expression in H295R cells was confirmed using Western blotting. When ACTH and forskolin were added to H295R cells, a reduction in PDGFD expression was seen, which was then restored by incubation with prochloraz, a known inhibitor of steroidogenesis. A dose-dependent, decrease in PDGFD expression was observed with beclometasone (over a 24 h incubation period) but not with beclometasone incubations beyond 24 h nor with fluticasone (at 24 or 48 h).

CONCLUSIONS

H295R cells express PDGFD protein, which can be modulated by incubation with steroidogenesis agonists and antagonists and additionally with exogenous beclometasone.

IMPACT

PDGFD is expressed in the human adrenal cell line, H295R, and expression can be modulated by beclometasone as well as agonists/antagonists of steroidogenesis. This builds on previous research that identified a SNP in PDGFD (rs591118) as an independent risk factor for adrenal suppression in adults and children with obstructive airway disease treated with inhaled corticosteroids. First in vitro experiments to support a link between the PDGF and cortisol production pathways, supporting the hypothesis that PDGFD variants can affect an individual's sensitivity to corticosteroid-induced adrenal suppression.

Baseline and peak cortisol response to the low dose short Synacthen test relates to indication for testing, age and sex

Objective

To review the outcomes of a simplified low dose Synacthen test (LDSST) performed in a tertiary endocrine service over seven years, and to examine for relationships between cortisol measurements and indication for testing, age and sex.

Design

Retrospective, observational study of LDSST performed in 2008 – 2014 (N=335) and 2016-2020 (N=160).

Methods

LDSST were performed by endocrine nurses. Synacthen 500ng/1.73m 2 administered as IV bolus, sampling at 0, 15, 25 and 35 minutes.

Results

Mean (± 1SD) baseline cortisol was 221 ± 120 nmol/L, peak 510 ± 166nmol/L and increment 210 ± 116 nmol/L. 336 (70%) of patients had a normal response (baseline cortisol >100nmol/L, peak >450nmol/L), 78 (16%) a suboptimal response (peak cortisol 350-450nmol/L) and were prescribed hydrocortisone to during periods of stress only, 67 (14%) an abnormal response (baseline <100nmol/L or peak <350nmol/L) and were prescribed daily hydrocortisone. Basal, peak and incremental increases in cortisol were higher in females (p=0.03, p<0.001, p=0.03 respectively). Abnormal results occurred most frequently in patients treated previously with pharmacological doses of glucocorticoids or structural brain abnormalities (p<0.0001).

Discussion

There are concerns that the specificity of the LDSST is poor. The low prevalence and strong association of abnormal results with indication for testing, suggests that over diagnosis occurred infrequently in this clinical setting.

Glucocorticoid induced adrenal insufficiency

Synthetic glucocorticoids are widely used for their anti-inflammatory and immunosuppressive actions. A possible unwanted effect of glucocorticoid treatment is suppression of the hypothalamic-pituitary-adrenal axis, which can lead to adrenal insufficiency. Factors affecting the risk of glucocorticoid induced adrenal insufficiency (GI-AI) include the duration of glucocorticoid therapy, mode of administration, glucocorticoid dose and potency, concomitant drugs that interfere with glucocorticoid metabolism, and individual susceptibility. Patients with exogenous glucocorticoid use may develop features of Cushing's syndrome and, subsequently, glucocorticoid withdrawal syndrome when the treatment is tapered down. Symptoms of glucocorticoid withdrawal can overlap with those of the underlying disorder, as well as of GI-AI. A careful approach to the glucocorticoid taper and appropriate patient counseling are needed to assure a successful taper. Glucocorticoid therapy should not be completely stopped until recovery of adrenal function is achieved. In this review, we discuss the factors affecting the risk of GI-AI, propose a regimen for the glucocorticoid taper, and make suggestions for assessment of adrenal function recovery. We also describe current gaps in the management of patients with GI-AI and make suggestions for an approach to the glucocorticoid withdrawal syndrome, chronic management of glucocorticoid therapy, and education on GI-AI for patients and providers.

Pharmacodynamic studies of nasal tetracosactide with salivary glucocorticoids for a noninvasive Short Synacthen Test

CONTEXT

The Short Synacthen Test (SST) is the gold standard for diagnosing adrenal insufficiency. It requires invasive administration of Synacthen, venous sampling, and is resource-intensive.

OBJECTIVE

To develop a nasally administered SST, with salivary glucocorticoids measurement, to assess the adrenal response.

DESIGN

We conducted 5 studies: 4 open-label, sequence-randomized, crossover, pharmacodynamic studies testing 6 doses/formulations and a repeatability study. Additionally, pharmacokinetic analysis was undertaken using our chosen formulation, 500 µg tetracosactide with mucoadhesive chitosan, Nasacthin003, in our pediatric study.

SETTING

Adult and children's clinical research facilities.

PARTICIPANTS

A total of 36 healthy adult males and 24 healthy children.

INTERVENTION

We administered all 6 nasal formulations using an European regulator endorsed atomization device. The IV comparators were 250 µg or 1 µg SST.

MAIN OUTCOME MEASURES

We analyzed paired blood and saliva samples for plasma cortisol and salivary cortisol and cortisone.

RESULTS

The addition of chitosan to tetracosactide and dose escalation increased peak cortisol response (P = 0.01 and 0.001, respectively). The bioavailability of Nasacthin003 was 14.3%. There was no significant difference in plasma cortisol at 60 minutes between 500 µg Nasacthin003 and 250 µg IV Synacthen (P = 0.17). The repeatability coefficient at 60 minutes was 105 nmol/L for IV Synacthen and salivary cortisol and cortisone was 10.3 and 21.1 nmol/L, respectively. The glucocorticoid response in children was indistinguishable from that of adults.

CONCLUSIONS

Nasal administration of Nasacthin003 generates equivalent plasma cortisol values to the 250-µg IV SST and, with measurement at 60 minutes of salivary cortisol or cortisone, provides a noninvasive test for adrenal insufficiency.

Inhaled corticosteroid-phobia and childhood asthma: Current understanding and management implications

Asthma is the most prevalent chronic disease in children. Inhaled corticosteroids (ICS) is the first-line controller therapy for children with persistent asthma, however, suboptimal compliance to ICS therapy remains as a major obstacle in paediatric asthma management. Steroid-phobia, the fear of side-effects and subsequent aversion of ICS, has been widely reported in parents of asthmatic children. The reported prevalence of steroid-phobia varies widely from 19% to 67% in different populations. The concerns about ICS frequently raised by parents include growth suppression, weight gain, bone weakness, addiction and psychiatric disturbances. Outside of growth suppression, which is statistically significant yet mild in clinical studies, the other concerns are not evidence-based and are misconceptions. Conflicting results have been reported regarding the impact of steroid-phobia on ICS compliance. In contrast, steroid-phobia has consistent and negative effects on asthma control in children. While asthma educational programmes have demonstrable benefits in general paediatric populations, the generalisability of such programmes to steroid-phobic parents remains undetermined. There is a paucity of data on specific educational programmes to clear misconceptions and reduce steroid-phobia. Given the continually raising prevalence of paediatric asthma, high-quality studies are warranted to investigate the prevalence and impact of steroid-phobia, with an ultimate goal of developing effective strategies to tackle steroid-phobia and improve asthma care in children.

Screening practices for paediatric asymptomatic adrenal suppression in Canada: Are we addressing this important risk?

Background

Children with adrenal suppression (AS), a potential side effect of glucocorticoids (GCs) may be asymptomatic, present with nonspecific signs and symptoms or with adrenal crisis. Asymptomatic AS (AAS) can only be diagnosed through screening. Identifying and treating asymptomatic patients before symptoms develop may reduce morbidity. Screening guidelines for AS are lacking. Consequently, screening practices are highly variable.

Objective

To assess (1) the screening practices for and recognition of paediatric AAS among clinicians in Canada and (2) the educational impact of a 2-year surveillance program of symptomatic AS cases.

Methods

Before and after a 2-year Canadian Paediatric Surveillance Program (CPSP) study of symptomatic AS, participants were surveyed through the CPSP. The prestudy survey was sent to 2,548 participants in March 2010 and the poststudy survey was sent to 2,465 participants in April 2013.

Results

Response rates were 32% for the prestudy survey and 21% for the poststudy survey. Between the pre- and poststudy surveys, the percentage of physicians who reported routinely screening patients on GCs for AS increased from 10% to 21% and the percentage who reported having a screening policy in their office/centre increased from 6% to 11%. There was no significant change in the percentage of physicians who had diagnosed a child/youth with AAS in the preceding year.

Conclusion

Frequency of screening for AAS increased following the 2-year study but remains low. Development of a clinical practice guideline should increase both awareness of asymptomatic AS among Canadian paediatricians and the identification of AAS, before symptoms develop.

Evaluation of Hypothalamic-Pituitary-Adrenal Axis Suppression following Cutaneous Use of Topical Corticosteroids in Children: A Meta-Analysis

BACKGROUND/AIMS

A meta-analysis was performed to determine the likelihood of hypothalamic-pituitary-adrenal (HPA) axis suppression following short-term cutaneous treatment of atopic dermatitis with topical corticosteroids (TCS) in pediatric patients.

METHODS

All published pediatric clinical trials evaluating TCS use with pre- and post-treatment HPA axis assessment by cosyntropin stimulation testing were included.

RESULTS

Of 128 eligible trials, 12 were selected for meta-analysis with a total of 522 participants. There were 20 observed cases of HPA axis suppression (3.8%, 95% CI 2.4-5.8). The percentage of HPA axis suppression with low- (classes 6-7), medium- (classes 3-5) and high-potency (classes 1-2) TCS use was 2% (3 of 148 patients, 95% CI 0.7-5.8), 3.1% (7 of 223 patients, 95% CI 1.5-6.3), and 6.6% (10 of 151 patients, 95% CI 3.6-11.8), respectively.

CONCLUSION

There is a low rate of reversible HPA axis suppression with the use of mid- to low-potency TCS compared to more potent formulations. In pediatric clinical practice, the limited use of mid- to low-potency TCS is rarely associated with clinically significant adrenal insufficiency or adrenal crisis. In the absence of signs and symptoms of adrenal insufficiency, there is little need to test the HPA axis of these patients.

Recovery of hypothalamo-pituitary-adrenal axis suppression during treatment with inhaled corticosteroids for childhood asthma

Objective

To describe recovery of adrenal insufficiency in asthmatic children treated with inhaled corticosteroids (ICS) and cortisol replacement therapy.

Design

Retrospective, observational study.

Patients

A total of 113 patients, 74 male; age 10.4 (3.3–16.5) years; beclomethasone-equivalent ICS dose, 800 μg, (100–1,000), tested by low dose short Synacthen (tetracosactide) test (LDSST), were studied. Test results were classified by basal and peak cortisol concentration: “normal” (basal >100 nmol/L, peak >500 nmol/L), “suboptimal” (basal >100 nmol/L, peak 350–499 nmol/L), “abnormal” (basal <100 nmol/L and/or peak <350 nmol/L). Patients with suboptimal results received hydrocortisone during periods of stress only, and those with abnormal responses received daily hydrocortisone, increased during periods of stress. A total of 73 patients (68%) had ≥2 LDSSTs over 2.2 years (0.2–7.7).

Measurements

Change in cortisol response to repeat LDSST (movement between diagnostic groups, difference in basal and peak cortisol >15% [2× the inter-assay coefficient of variation]), change in BMI and height standard deviation score (SDS).

Results

Baseline test results were abnormal in 17 patients (15%) and all of them had repeat tests. In 13 patients (76%), test results improved (normal in six, suboptimal in seven) and four (24%) remained abnormal. Baseline tests results were suboptimal in 54 patients (48%), of whom 50 (93%) were retested. Repeat tests were normal in 36 patients (72%), remained suboptimal in 11 (22%), and were abnormal in three (6%). Baseline tests results were normal in 42 patients, of whom six patients (14%) were retested. Results remained normal in three (50%), were suboptimal in two (33%), and abnormal in one (17%). Basal and peak cortisol levels increased by >15% in 33/73 (45%) and 42/73 (57%) patients, respectively, and decreased by >15% in 14/73 (19%) and 7/73 (10%), respectively. There was no significant change in height or BMI SDS.

Conclusion

Recovery of adrenal function is common and occurs during continued ICS and cortisol replacement therapy.

Chronic Corticosterone Treatment During Adolescence Has Significant Effects on Metabolism and Skeletal Development in Male C57BL6/N Mice

Glucocorticoids are potent modulators of metabolic and behavioral function. Their role as mediators in the "stress response" is well known, but arguably their primary physiological function is in the regulation of cellular and organismal metabolism. Disruption of normal glucocorticoid function is linked to metabolic disease, such as Cushing syndrome. Glucocorticoids are also elevated in many forms of obesity, suggesting that there are bidirectional effects of these potent hormones on metabolism and metabolic function. Adolescence is a time of rapid physical growth, and disruptions during this critical time likely have important implications for adult function. The hypothalamic-pituitary-adrenal axis continues to mature during this period, as do tissues that respond to glucocorticoids. In this work, we investigate how chronic noninvasive exposure to corticosterone affects metabolic outcomes (body weight, body composition, insulin, and glucose homeostasis), as well as changes in bone density in both adult and adolescent male mice. Specifically, we report a different pattern of metabolic effects in adolescent mice compared with adults, as well as an altered trajectory of recovery in adolescents and adults. Together, these data indicate the profound influence that adolescent development has on the metabolic outcomes of chronic corticosterone exposure, and describe a tractable model for understanding the short- and long-term impacts of hypercortisolemic states on physiological and neurobehavioral functions.

Salivary cortisol and cortisone in the clinical setting

PURPOSE OF REVIEW

A resurgence of interest in salivary biomarkers has generated evidence for their value in assessing adrenal function. The advantages of salivary measurements include only free hormone is detected, samples can be collected during normal daily routines and stress-induced cortisol release is less likely to occur than during venepuncture. We review the use of salivary biomarkers to diagnose and monitor patients for conditions of cortisol excess and deficiency and discuss the value of measuring salivary cortisone versus salivary cortisol.

RECENT FINDINGS

Developments in laboratory techniques have enabled the measurement of salivary hormones with a high level of sensitivity and specificity. In states of altered cortisol binding, salivary biomarkers are more accurate measures of adrenal reserve than serum cortisol. Salivary cortisone is a superior marker of serum cortisol compared with salivary cortisol, specifically when serum cortisol is low and during hydrocortisone therapy when contamination of saliva may result in misleading salivary cortisol concentrations.

SUMMARY

Salivary cortisol and cortisone can be used to assess cortisol excess, deficiency and hydrocortisone replacement, with salivary cortisone having the advantage of detection when serum cortisol levels are low and there is no interference from oral hydrocortisone.

Symptomatic adrenal suppression among children in Canada

BACKGROUND

Adrenal suppression (AS) is an under-recognised side effect of glucocorticoid (GC) use. AS may go undetected until a physiological stress precipitates an adrenal crisis. The incidence of AS has not been established. We sought to estimate the minimum national incidence and presenting features of paediatric symptomatic AS.

METHODS

Through the established methodology of the Canadian Paediatric Surveillance Program, over 2500 paediatricians were surveyed monthly for 2 years (April 2010-March 2012) to report new cases of symptomatic AS.

RESULTS

Forty-six cases of symptomatic AS were confirmed. The estimated annual incidence is 0.35/100 000 children aged 0-18 years (95% CI 0.26 to 0.47). The most common presentations were growth failure (35%), non-specific symptoms (28%) or both (13%). Adrenal crisis occurred in six cases (13%). Thirty-seven children (80%) had received inhaled corticosteroid (ICS) alone or in combination with other GC forms. Many children received high but commonly prescribed doses of ICS.

CONCLUSIONS

AS is responsible for significant morbidity in children, including susceptibility to adrenal crisis. The minimal estimated incidence reported is for the entire paediatric population and would be much higher in the at-risk group (ie, children treated with GCs). Close monitoring of growth and possible symptoms of AS, which may be non-specific, are important in children on all forms of GC therapy including ICS. To reduce the risk of AS, physicians must be aware of the risk of AS, revisit GC doses frequently and use the lowest effective dose.

Adrenal Insufficiency after Chronic Swallowed Glucocorticoid Therapy for Eosinophilic Esophagitis

OBJECTIVE

To establish the prevalence of adrenal insufficiency (AI) in children with eosinophilic esophagitis treated with swallowed fluticasone propionate (FP) or budesonide.

STUDY DESIGN

Children treated with FP or budesonide for ≥ 6 months underwent a low-dose adrenocorticotropin stimulation test. Patients using systemic, inhaled, intranasal, or topical glucocorticoids were excluded. The primary outcome is AI, defined as peak serum cortisol <18 μg/dL (≤ 495 nmol/L).

RESULTS

Of 58 patients (81% male), 67% were on FP (median age 13.7 years [range 4.3-19.1], dose 1320 μg/d [440-1760], treatment duration 4.0 years [0.6-13.5]). Thirty-three percent were on budesonide (median age 10.7 years [range 3.2-17.2], dose 1000 μg/d [500-2000], treatment duration 3.4 years [0.6-7.7]). The overall prevalence of abnormal peak cortisol response (≤ 20 μg/dL) was 15% (95% CI 6%-25%) (indeterminate [18-20 μg/dL] 5% [n = 3] vs AI [<18 μg/dL] 10% [n = 6]). All patients on budesonide had a normal response vs only 77% of patients on FP (P = .02), all of whom were taking FP at a dose >440 μg/d.

CONCLUSIONS

AI was present in 10% of children treated with swallowed glucocorticoids for ≥ 6 months and was found only in those treated with FP >440 μg/d. We recommend low-dose adrenocorticotropin stimulation testing in children treated long term with high dose FP to allow early detection of AI.

Adrenal responses to a low-dose short synacthen test in children with asthma

OBJECTIVES

Corticosteroids are known to cause adrenal suppression. The aim of this study was to assess clinical factors affecting responses to a low dose short synacthen test (LDSST) in asthmatic children using corticosteroids.

DESIGN

Patients were recruited from secondary care paediatric asthma populations within the UK.

PATIENTS

Asthmatic children (5-18 years), receiving corticosteroids, underwent a LDSST (n = 525).

MEASUREMENTS

Demographics and corticosteroid doses were tested for association with baseline and peak (stimulated) cortisol concentrations.

RESULTS

Baseline cortisol was significantly associated with age (log baseline increased 0·04 nm per year of age, P < 0·0001), but not with gender or corticosteroid dose. Peak cortisol was significantly associated with total corticosteroid cumulative dose (decreased 0·73 nm per 200 mcg/day, P < 0·001) but not with age, gender inhaled/intranasal corticosteroid cumulative dose or number of courses of rescue corticosteroids. Biochemically impaired response (peak cortisol ≤500 nm) occurred in 37·0% (161/435) overall, including children using GINA low (200-500 mcg/day beclomethasone-CFC equivalent 32%, n = 60), medium (501-1000 mcg/day (33%, n = 57) and high (>1000 mcg/day 40%, n = 13) doses of inhaled corticosteroid (ICS) similarly, and 36·6% of those using fluticasone ICS ≥500 mcg/day (71/194). Impaired response was more frequent in patients on regular oral corticosteroids (66%, n = 27, P < 0·001).

CONCLUSION

Children with asthma can develop biochemical adrenal suppression at similar frequencies for all ICS preparations and doses. The clinical consequence of biochemical suppression needs further study.

CSACI position statement: systemic effect of inhaled corticosteroids on adrenal suppression in the management of pediatric asthma

Asthma is a chronic inflammatory disease of the airways that affects a growing number of children and adolescents. Inhaled corticosteroids (ICS) are the mainstay of treatment in persistent asthma, with a stepwise approach to increasing doses of ICS depending on asthma severity and control. ICS have known local and systemic side effects, of which adrenal suppression is still under-recognized. The latter is associated with chronic exposure and higher doses, although it has rarely been reported in children receiving low doses for a short period of time. The Canadian Society of Allergy and Clinical Immunology (CSACI) therefore recommends that physicians screen for adrenal suppression in children receiving high doses for more than 6 months and to consider screening those on medium dose if the risk is deemed higher by factors that increase an individual's systemic corticosteroid exposure. Morning serum cortisol level can be used as a screening tool and abnormal results or normal results with a high index of suspicion should be confirmed with low-dose ACTH stimulation tests.

Diagnosis and management of adrenal insufficiency

Adrenal insufficiency continues to be a challenge for patients, their physicians, and researchers. During the past decade, long-term studies have shown increased mortality and morbidity and impaired quality of life in patients with adrenal insufficiency. These findings might, at least partially, be due to the failure of glucocorticoid replacement therapy to closely resemble physiological diurnal secretion of cortisol. The potential effect of newly developed glucocorticoid drugs is a focus of research, as are the mechanisms potentially underlying increased morbidity and mortality. Adrenal crisis remains a threat to lives, and awareness and preventative measures now receive increasing attention. Awareness should be raised in medical teams and patients about adrenal insufficiency and management of adrenal crisis to improve clinical outcome.

Early morning salivary cortisol and cortisone, and adrenal responses to a simplified low-dose short Synacthen test in children with asthma

OBJECTIVE

To examine serum cortisol responses to a simplified low-dose short Synacthen test (LDSST) in children treated with inhaled corticosteroids (ICS) for asthma and to compare these to early morning salivary cortisol (EMSC) and cortisone (EMSCn) levels.

DESIGN

Early morning salivary cortisol and EMSCn samples were collected for three consecutive days. On day three, Synacthen 500 ng/1·73 m(2) was administered intravenously. Samples were collected at 0, 15, 25, 35 min.

RESULTS

A total of 269 subjects (160 M: 109 F), median (range) age 10·0 (5·1-15·2) years were studied. Peak cortisol in the LDSST was <500 nmol/l in 101 subjects (37·5%) and <350 nmol/l in 12 subjects (4·5%). Basal cortisol correlated with peak cortisol: r = 0·55, (95% CI: 0·46, 0·63, P < 0·0001). Time at which peak cortisol concentration was achieved was significantly related to the value of peak cortisol (P < 0·0001), with higher cortisol peaks occurring later in the test and lower cortisol peaks occurring earlier. EMSC and EMSCn had no predictive value for the identification of patients with a peak cortisol <500 nmol/l. EMSCn was superior to EMSC in identifying patients with a peak cortisol <350 nmol/l: a minimum EMSCn cut-off value of 12·5 nmol/l gave a negative predictive value of 99·2% and positive predictive value of 30·1%.

CONCLUSION

Our data illustrate that basal measures of cortisol are likely to be of value in screening populations for patients at greatest risk of adrenal crisis. EMSCn shows promise as a screening tool for the identification of patients with severe adrenal insufficiency.

Why glucocorticoid withdrawal may sometimes be as dangerous as the treatment itself

Glucocorticoid therapy is widely used, but withdrawal from glucocorticoids comes with a potential life-threatening risk of adrenal insufficiency. Recent case reports document that adrenal crisis after glucocorticoid withdrawal remains a serious problem in clinical practice. Partly due to difficulties in inter-study comparison the true prevalence of glucocorticoid-induced adrenal insufficiency is unknown, but it might be somewhere between 46 and 100% 24h after glucocorticoid withdrawal, 26-49% after approximately one week, and some patients show prolonged suppression lasting months to years. Adrenal insufficiency might therefore be underdiagnosed in clinical practice. Clinical data do not permit accurate estimates of a lower limit of glucocorticoid dose and duration of treatment, where adrenal insufficiency will not occur. Due to individual variation, neither the glucocorticoid dose nor the duration of treatment can be used reliably to predict adrenal function after glucocorticoid withdrawal. Also the recovery rate of the adrenal glands shows individual variation, which may be why there is currently insufficient evidence to prove the efficacy and safety of different withdrawal regimens. Whether a patient with an insufficient response to an adrenal stimulating test develops clinically significant adrenal insufficiency depends on the presence of stress and resulting glucocorticoid demand and it is thus totally unpredictable and can change relative fast. Adrenal insufficiency should therefore always be taken seriously. Individual variation in hypothalamic-pituitary-adrenal axis function might be due to differences in glucocorticoid sensitivity and might be genetic. Further awareness of the potential side effect of withdrawal of glucocorticoid and further research are urgently needed.

Requirement for age-specific peak cortisol responses to insulin-induced hypoglycaemia in children

OBJECTIVE

Based on adult data, a peak cortisol response ≥500 nmol/l to insulin-induced hypoglycaemia constitutes a normal. Age-specific reference ranges for basal morning cortisol have been developed for clinical use in the paediatric population. Such reference ranges are not clearly established for peak cortisol responses to insulin-induced hypoglycaemia despite limited data suggesting an effect of age on peak cortisol. The aims of this study were to assess factors affecting the cortisol response to insulin-induced hypoglycaemia in children and to determine whether the peak cortisol response was related to age.

DESIGN

The present study was a retrospective cohort study.

METHODS

Retrospective analysis of children and adolescents aged ≤18 years undergoing the insulin tolerance test with adequate hypoglycaemia was undertaken. Patients with hypopituitarism or severe hypothalamic-pituitary-adrenal axis impairment (peak cortisol value <400 nmol/l) or using systemic glucocorticoids were excluded.

RESULTS

Two hundred and twenty-three tests were analysed. Peak cortisol responses ≥500 nmol/l occurred in 183 (82%) tests. Age was negatively associated with peak cortisol responses (r=-0.15, P=0.03). A peak cortisol response <500 nmol/l was significantly less common in patients aged <12 years (9/97 (9%) vs 31/126 (25%); P=0.004). In children aged <12 years, the median (5th-95th centiles) peak cortisol values were 610 (480-806) nmol/l compared with 574 (442-789) nmol/l in children aged ≥12 years (P<0.004). Similarly, median cortisol increment was significantly higher in younger patients (301 nmol/l compared with 226 nmol/l (P=0.0004)).

CONCLUSIONS

Use of a single peak cortisol threshold in children of all ages is not appropriate and will result in overdiagnosis of adrenal insufficiency in adolescents.

Acute asthma exacerbations in childhood: risk factors, prevention and treatment

Asthma is a heterogeneous disease more appropriately seen as a syndrome rather than a single pathologic entity. Although it can remain quiescent for extended time periods, the inflammatory and remodeling processes affect the bronchial milieu and predispose to acute and occasionally severe clinical manifestations. The complexity underlying these episodes is enhanced during childhood, an era of ongoing alterations and maturation of key biological systems. In this review, the authors focus on such sudden-onset events, emphasizing on their diversity on the basis of the numerous asthma phenotypes.

Lack of sensitivity of the 1-μg low-dose ACTH stimulation test in a paediatric population with suboptimal cortisol responses to insulin-induced hypoglycaemia

CONTEXT

The insulin-tolerance test (ITT) is the gold standard for evaluation of the hypothalamic-pituitary-adrenal (HPA) axis. The low-dose ACTH stimulation test is increasingly used for evaluation of secondary adrenal insufficiency as several studies performed in adults have demonstrated high sensitivity and specificity when compared to the ITT. Whether the ACTH stimulation test demonstrates similar sensitivity in a paediatric and adolescent population compared with the gold standard is unclear.

OBJECTIVE

To compare the sensitivity of the low-dose (1-μg) Synacthen(™) test (LDSST) and the gold-standard ITT in a paediatric and adolescent population.

DESIGN AND PATIENTS

A retrospective review of 42 consecutive LDSSTs in children and adolescents with suboptimal cortisol responses (peak <500 nm) on ITT.

RESULTS

Thirty-one patients (74%) had an adequate cortisol response to low-dose Synacthen(™) (sensitivity 26%). Patients had a higher cortisol increment with the LDSST than ITT (median Δ cortisol 294 vs 168 nm, P < 0.0001) and correspondingly a higher cortisol peak (median peak cortisol 572 vs 396 nm, P < 0.0001). Patients who had a suboptimal peak cortisol both on ITT and on LDSST had a lower baseline cortisol on ITT (median 178 vs 227 nm, P = 0.04). Peak cortisol on ITT was significantly higher in patients who had a subsequent normal LDSST than those that did not (median 417 vs 300 nm, P = 0.0005).

CONCLUSIONS

The 1-μg LDSST lacks sensitivity in detection of secondary adrenal insufficiency in children when compared to the gold-standard ITT.

Moderate dose inhaled corticosteroid-induced symptomatic adrenal suppression: case report and review of the literature

Inhaled corticosteroids (ICS) are drugs of choice for persistent asthma. Less than 500 µg/d of fluticasone are believed to be safe. We found 92 cases of adrenal suppression in PubMed; among these cases there were 13 children who took 500 µg/d or less of fluticasone. Adrenal insufficiency was diagnosed in a 7-year-old boy on 460 µg ICS for 16 months, with a diagnosis of chronic persistent asthma. A random cortisol was nondetectable as was an early morning cortisol. ICS have greatly improved the day-to-day lives of children with chronic persistent asthma. Parents of children younger than 12 years, who use at least 400 µg of inhaled fluticasone (or bioequivalent), must be given oral and written instructions about warning symptoms of hypocortisolism. Major stress such as surgery, gastrointestinal, bronchopulmonary, or other systemic infections, and heat stress may mandate a written plan of action for use by hospital physicians.

Iatrogenic Cushing's syndrome with inhaled steroid plus antidepressant drugs

Current guidelines recommend the use of inhaled corticosteroids (ICS) for suppression of airway inflammation in patients with asthma. Although it is well known that ICS cause dose-related adrenocortical suppression, it is less known that they can lead to iatrogenic Cushing's syndrome (CS). Fluticasone propionate (FP) is an ICS more potent than beclomethasone and budesonide. FP is metabolized as mediated by cytochrome P450 3A4 in the liver and the gut. Systemic bioactivity of FP can increase with the use of drugs that affect the cytochrome P450. Herein, we report the rapid development of iatrogenic CS in a patient receiving paroxetine and mirtazepine for 12 weeks in addition to inhaled FP.

Cost considerations of therapeutic options for children with asthma

Asthma is a prevalent health condition in children, with economic implications for the individual and their family, as well as for societies with nationalized healthcare. Pharmaceutical cost is the main driver of healthcare expenditure in asthma. Existent explicit guidelines are meant to guide asthma management across all age groups, but they are failing. Pharmacologic management of asthma consists of a stepwise treatment approach to achieve symptom control. Various studies suggest a significant number of medical practitioners are prescribing inhaled corticosteroids (ICS) and ICS/long-acting beta agonist (LABA) combination inhalers inappropriately, including prescribing high doses of ICS without specialist consultation. ICS/LABA combination inhalers should only be used in persistent asthmatics, which account for approximately 5% of all children with asthma. Despite this, there is an increase in prescribing rates of ICS/LABA combination inhalers in the context of a decrease in the prevalence of asthma. Furthermore, there is inappropriate prescribing of ICS/LABA combination inhalers in children under 5 years of age, and initiation of relatively more expensive ICS/LABA combination inhalers in patients who have not previously been prescribed ICS. There is evidence to suggest that cost is a significant barrier to asthma management, especially for the more expensive ICS/LABA combination inhalers. Hence, prescribing cost-effective asthma medications appropriately is one of the most important strategies in reducing the morbidity and mortality associated with asthma. It is incumbent on every medical practitioner to not prescribe expensive medications if not indicated, both for the sake of the patient and for society.

Inhaled corticosteroids should be the first line of treatment for children with asthma

Although montelukast is claimed to be preferable to inhaled corticosteroids in children with asthma and allergic rhinitis, virus-induced exacerbations, exercise induced asthma, and in those experiencing difficulties with inhalation therapy, there is no scientific evidence to support any of these claims. In comparative trials and systematic reviews, inhaled corticosteroids are clearly more effective than montelukast in reducing asthma exacerbations, improving lung function, symptom scores, and rescue medication use. The effects on exercise induced bronchoconstriction appear to be similar. Because of their superior efficacy and excellent long-term efficacy and safety profile, inhaled corticosteroids are the treatment of first choice for the maintenance therapy of childhood asthma, irrespective of age or clinical phenotype.

Salivary cortisol levels in prepubertal children using inhaled corticosteroids with or without concurrent intranasal corticosteroids

BACKGROUND

Inhaled corticosteroids (ICS) and intranasal steroids (INS) are frequently co-administered in children with asthma and rhinitis. In contrast to monotherapy with ICS or INS, little is known about the safety of concurrent use of topical steroids on hypothalamic-pituitary-adrenal (HPA) axis function in prepubertal children.

OBJECTIVE

Comparison of morning salivary cortisol levels in prepubertal children using maintenance treatment with ICS with and without concurrent use of INS to steroid naïve control groups (healthy children, and children with constipation who are under pediatric care).

METHODS

Cross-sectional observational study in prepubertal children (6-12 years) using ICS alone (n = 41) or in combination with INS (n = 22), compared to different control groups with no steroid treatment (18 healthy children, and 28 children with constipation). Morning salivary cortisol levels were determined from saliva samples collected at home.

RESULTS

The morning salivary cortisol levels of the healthy children (8.7 nmol/L; 95% CI 5.9-18.8), and the children with constipation (8.9 nmol/L; 8.0-11.3) were comparable. The salivary cortisol levels of prepubertal children using ICS (median 4.7 nmol/L; 95% CI 4.6-6.9) or a combination of ICS and INS (5.1 nmol/L; 4.2-7.6) were comparable, but significantly reduced compared to both control groups. There was no correlation between salivary cortisol level and age, duration of disease, or cumulative daily dose of topical steroids.

CONCLUSION

Salivary cortisol levels in prepubertal children using ICS, with or without concurrent use of INS, were comparable. However, salivary cortisol levels were significantly reduced compared to steroid naïve controls, irrespective of the cumulative daily dose of topical steroids. Pediatr. Pulmonol. 2011; 46:1055-1061. © 2011 Wiley Periodicals, Inc.

Adrenal suppression: A practical guide to the screening and management of this under-recognized complication of inhaled corticosteroid therapy

Inhaled corticosteroids (ICSs) are the most effective anti-inflammatory agents available for the treatment of asthma and represent the mainstay of therapy for most patients with the disease. Although these medications are considered safe at low-to-moderate doses, safety concerns with prolonged use of high ICS doses remain; among these concerns is the risk of adrenal suppression (AS). AS is a condition characterized by the inability to produce adequate amounts of the glucocorticoid, cortisol, which is critical during periods of physiological stress. It is a proven, yet under-recognized, complication of most forms of glucocorticoid therapy that can persist for up to 1 year after cessation of corticosteroid treatment. If left unnoticed, AS can lead to significant morbidity and even mortality. More than 60 recent cases of AS have been described in the literature and almost all cases have involved children being treated with ≥500 μg/day of fluticasone.

The risk for AS can be minimized through increased awareness and early recognition of at-risk patients, regular patient follow-up to ensure that the lowest effective ICS doses are being utilized to control asthma symptoms, and by choosing an ICS medication with minimal adrenal effects. Screening for AS should be considered in any child with symptoms of AS, children using high ICS doses, or those with a history of prolonged oral corticosteroid use. Cases of AS should be managed in consultation with a pediatric endocrinologist whenever possible. In patients with proven AS, stress steroid dosing during times of illness or surgery is needed to simulate the protective endogenous elevations in cortisol levels that occur with physiological stress.

This article provides an overview of current literature on AS as well as practical recommendations for the prevention, screening and management of this serious complication of ICS therapy.

[Inhaled corticosteroids in asthma: which have the best tolerance?]

Asthmatic syndrome, better definition of asthma, is an inflammatory chronic disease, probably the most frequent in pediatrics. An important characteristic of asthma is the bronchial inflammation with a complex network of cells and inflammatory mediators of pivotal importance in the pathogenesis. The long term control and treatment of this disease are cardinal points of the management of asthmatic syndrome. Inhaled corticosteroids (ICS) are the first-line treatment for persistent asthma in children of any age. The adverse events of the inhaled steroids on growth, bone mineralization, and hypothalamic-pituitary adrenal (HPA) axis function are the main concerns for the pediatricians. The long-term effects on growth and bone mineralization are actually reassuring. Good tolerance is achieved on hypothalamic-pituitary adrenal axis function with low to moderate doses in children. Scientific and clinical researches are pointed to find out molecules able to improve clinical efficacy of ICS with better tolerance and higher reduction of adverse events.

Acute adrenal crisis in an asthmatic child treated with inhaled fluticasone proprionate

Adrenal suppression secondary to prolonged inhaled corticosteroid use is usually limited to biochemical abnormalities, with no obvious clinical effects. Acute adrenal crisis is much rarer event but has been reported with increasing frequency. We report a case of a 7-year-old asthmatic child who presented with an acute history of lethargy after a respiratory infection. He was maintained on 220 mug/day of fluticasone propionate for several years. Initial evaluation revealed severe adrenal suppression, with undetectable cortisol levels and minimal response after stimulation with ACTH. After fluticasone was discontinued, a gradual recovery of the adrenal axis was seen. This case shows that acute adrenal crisis may be a consequence even at the usual prescribed doses, stressing the importance of using the lowest dose of inhaled steroids needed to control symptoms and having an increased awareness of this complication.

Repeatability of the low-dose ACTH test in asthmatic children on inhaled corticosteroids

AIM

To assess the repeatability of low-dose Synacthen test (LDST) in asthmatic children receiving high-dose fluticasone propionate (FP).

METHODS

Low-dose Synacthen test was performed on 18 children with stable chronic asthma treated with FP at a constant daily dose of > or =500 microg and repeated 1 month later. Repeatability was assessed using the Kappa statistic for categorical variables.

RESULTS

Fifteen patients had consistent results (either two normal or two abnormal responses) and three patients had inconsistent results (one normal and one abnormal response). The Kappa statistic was 0.56 indicating fair to good agreement between the tests.

CONCLUSION

The results of adrenal function testing in patients on inhaled steroids can have major implications for patient management, making it important to use a test with excellent repeatability. The LDST conducted using our protocol does not fulfil this criterion.

Outcomes in clinical trials of inhaled corticosteroids for children with asthma are narrowly focussed on short term disease activity

BACKGROUND

Little work has been done to determine which outcomes should be measured in randomised controlled trials (RCTs) in children with asthma. Drug regulatory authorities require that short term disease activity is measured, but other outcome domains are not mandatory for licensing and marketing purposes. We aimed to identify whether any domains were underrepresented in RCTs of regular therapies for children with asthma over a 20 year period, and to examine what consistency there was between RCTs in the outcomes used to assess the domains.

METHODOLOGY/PRINCIPAL FINDINGS

By searching the Cochrane Central Register of Controlled Trials in January 2008, we identified all parallel-group RCTs, published between January 1988 and December 2007, which assessed inhaled corticosteroids (ICS) as regular therapy for children with asthma. We evaluated how frequently RCTs measured the following pre-defined domains: disease activity; disease damage; functional status; quality of life; health resource utilisation; and adverse effects of therapy. Our initial search identified 1668 abstracts, of which 412 were retrieved in full. 159 RCTs, of which 115 involved only children and 44 involved children and adults, were included in the review. Disease activity was measured in 157 RCTs, adverse effects of ICS in 135, functional status in 25, quality of life in 21, and health resource utilisation in 17. No RCT measured long term disease damage, although two used FEV1 as a measure of 'lung growth'. RCTs were inconsistent in the outcomes used to measure the domains.

CONCLUSIONS

Short term disease activity is the most frequently measured outcome domain in RCTs in children with asthma. Effects of regular therapies on functional status, quality of life, and long term consequences of asthma are infrequently assessed. A core set of outcomes, developed using consensus techniques, would standardise the measurement of appropriate outcomes in these RCTs. Involving patients would identify outcomes which are most relevant from their perspective.

Dysregulation of the stress response in asthmatic children

The stress system co-ordinates the adaptive responses of the organism to stressors of any kind. Inappropriate responsiveness may account for increased susceptibility to a variety of disorders, including asthma. Accumulated evidence from animal models suggests that exogenously applied stress enhances airway reactivity and increases allergen-induced airway inflammation. This is in agreement with the clinical observation that stressful life events increase the risk of a new asthma attack. Activation of the hypothalamic-pituitary-adrenal (HPA) axis by specific cytokines increases the release of cortisol, which in turn feeds back and suppresses the immune reaction. Data from animal models suggest that inability to increase glucocorticoid production in response to stress is associated with increased airway inflammation with mechanical dysfunction of the lungs. Recently, a growing body of evidence shows that asthmatic subjects who are not treated with inhaled corticosteroids (ICS) are likely to have an attenuated activity and/or responsiveness of their HPA axis. In line with this concept, most asthmatic children demonstrate improved HPA axis responsiveness on conventional doses of ICS, as their airway inflammation subsides. Few patients may experience further deterioration of adrenal function, a phenomenon which may be genetically determined.

Corticosteroid physiology and principles of therapy

The adrenal cortex secretes glucocorticoids (GC), mineralocorticoids (MC) and androgens. GC maintain homeostasis, MC regulate fluid and electrolyte balance and adrenal androgens contribute to development of secondary sexual characteristics. Pharmacologic GC therapy is frequently indicated in the pediatric age group. Besides having many important side effects, prolonged high dose systemic GC therapy has a suppressive effect on endogenous steroid production. Therefore, GC therapy should be withdrawn gradually and stopped based on assessment of hypothalamo-pituitary-adrenal (HPA) axis recovery. Patients with HPA axis suppression require physiological replacement of GC along with enhancement of doses during periods of stress. Due to its immunosuppressive effects, issues about safety and efficacy of live virus vaccines in patients receiving systemic high dose GC therapy must be borne in mind.

What is new in the management of childhood asthma?

The prevalence of asthma has increased in developed countries. The efficacy of available drugs in those with severe persistent disease is limited. This has led to a renewed search for the reasons for failures of the existing treatment and for novel concepts. Treatment with inhaled corticosteroids, and to a much lesser extent theophylline, can reduce the survival of inflammatory cells including eosinophils. Emerging trends in treatments for asthma could include strategies to alter the cytokine/chemokine balance. It is evident that the current ICS are already very efficient and safe, it will be difficult to introduce further improved formulations. Perhaps the most fruitful effort shall be in developing patient friendly easy to use targeted delivery systems. The newer therapies are planned for the several upstream targets and may have potential to prevent the disease. Various potential therapies are being worked upon like-targeting prevention of T cell activation, modulation of Th-1/Th-2 differentiation, inhibition of Th-2 related cytokines, Th-1/Th-2 modulation, inhibition of downstream mediators etc. The new strategy shall perhaps lie with matching the patients and their disease with the most suitable therapy.

Low-dose and high-dose adrenocorticotropin testing: indications and shortcomings

PURPOSE OF REVIEW

The 250 microg adrenocorticotropin test (high-dose test) is the most commonly used adrenal stimulation test, though the use of physiologic doses (1.0 microg or 0.5 microg/1.73 m) (low-dose test) has recently gained wider acceptance. These variants and the use of adrenocorticotropin test in the ICU, however, remain controversial. The validity of the low-dose test and the parameters for evaluation of high- and low-dose tests in different situations need reevaluation.

RECENT FINDINGS

In the last few years, numerous studies have used the low-dose test as a single test following previous findings that it is more sensitive and accurate than the high-dose test. It is used mainly in secondary adrenal insufficiency and after treatment with therapeutic glucocorticosteroids to define hypothalamo-pituitary-adrenal suppression. Unless there is a very recent onset of disease, the results are interpreted by most researchers as diagnostic. The treatment of relative adrenal insufficiency, based on delta cortisol, has not yielded proof of correlation between this diagnosis and better prognosis with glucocorticoid treatment.

SUMMARY

For interpretation of an adrenocorticotropin test, only peak - and not delta - cortisol should be used. The use of 240-300 mg of hydrocortisone daily in ICU patients, including septic shock, should be considered as pharmacologic, rather than as a replacement dose. Using the low-dose test for this purpose will lead to further misdiagnosis.

The hypothalamic-pituitary-adrenal axis in asthmatic children

Reduced responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis in patients with various chronic allergic inflammatory disorders and a blunted HPA axis response of poorly controlled asthmatics before long-term treatment with inhaled corticosteroids (ICS) have been reported. It seems that pro- and anti-inflammatory cytokines might be involved in the attenuation of cortisol and adrenocorticotropic hormone (ACTH) responses to stress in these patients. Although long-term ICS treatment might produce mild adrenal suppression in some asthmatic children, improvement of adrenal function has been detected in the majority of cases. We postulate that the anti-inflammatory effects of ICS result both in asthma remission and HPA axis improvement. Adrenal suppression of some asthmatic patients on maintenance ICS seems to be a separate phenomenon, possibly constitutionally or genetically determined.

Oral corticosteroid-dependent asthma: a 30-year review

OBJECTIVE

To identify novel aspects of the pathogenesis, therapeutic options, and prophylaxis measures of corticosteroid-dependent asthma.

DATA SOURCES

PubMed searches were undertaken of studies published between 1966 and 2006 on the pathogenesis of and corticosteroid-sparing therapies for corticosteroid-dependent asthma. Identified review articles were surveyed for additional and earlier citations. Recent American Academy of Asthma, Allergy, and Immunology meeting abstracts were also searched to identify other recently published and unpublished studies.

STUDY SELECTION

Inclusion of studies in the review was decided by simple agreement of both reviewers, who independently read the "Methods" and "Discussion" sections of articles identified using the search strategy. Quality assessment was performed by the 2 reviewers.

RESULTS

High-dose inhaled corticosteroids are the first-line option for corticosteroid-dependent asthmatic patients with clear efficacy. Omalizumab is effective in reducing oral corticosteroid requirements in allergic asthma. Methotrexate, gold, and cyclosporine have corticosteroid-sparing effects clinically that must be weighed against a serious adverse effect profile. Nebulized diuretics and lidocaine, with a low adverse effect profile, offer promising results but require further study. Clarithromycin and telithromycin seem to have an independent mechanism of inflammatory modulation, but their effect on corticosteroid-dependent asthma remains to be seen. Etanercept offers only early clinical evidence of a role in corticosteroid-dependent asthma.

CONCLUSIONS

With no clear consensus on corticosteroid-sparing treatment in corticosteroid-dependent asthmatic patients, systemic glucocorticoids remain the foremost therapy, with adverse effects that require monitoring and prophylaxis.

Fluticasone versus beclomethasone or budesonide for chronic asthma in adults and children

BACKGROUND

Beclomethasone dipropionate (BDP) and budesonide (BUD) are commonly prescribed inhaled corticosteroids for the treatment of asthma. Fluticasone propionate (FP) is newer agent with greater potency in in-vitro assays.

OBJECTIVES

To compare the efficacy and safety of Fluticasone to Beclomethasone or Budesonide in the treatment of chronic asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group trial register (January 2007) and reference lists of articles. We contacted trialists and pharmaceutical companies for additional studies and searched abstracts of major respiratory society meetings (1997 to 2006).

SELECTION CRITERIA

Randomised trials in children and adults comparing Fluticasone to either Beclomethasone or Budesonide in the treatment of chronic asthma.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed articles for inclusion and methodological quality. One reviewer extracted data. Quantitative analyses were undertaken using RevMan analyses 1.0.1.

MAIN RESULTS

Seventy-one studies (14,602 participants) representing 74 randomised comparisons met the inclusion criteria. Methodological quality was fair. Dose ratio 1:2: FP produced a significantly greater end of treatment FEV1 (0.04 litres (95% CI 0 to 0.07 litres), end of treatment and change in morning PEF, but not change in FEV1 or evening PEF. This applied to all drug doses, age groups, and delivery devices. No difference between FP and BDP/BUD were seen for trial withdrawals. FP led to fewer symptoms and less rescue medication use. When given at half the dose of BDP/BUD, FP led to a greater likelihood of pharyngitis. There was no difference in the likelihood of oral candidiasis. Plasma cortisol and 24 hour urinary cortisol was measured frequently but data presentation was limited. Dose ratio 1:1: FP produced a statistically significant difference in morning PEF, evening PEF, and FEV1 over BDP or BUD. The effects on exacerbations were mixed. There were no significant differences incidence of hoarseness, pharyngitis, candidiasis, or cough.

AUTHORS' CONCLUSIONS

Fluticasone given at half the daily dose of beclomethasone or budesonide leads to small improvements in measures of airway calibre, but it appears to have a higher risk of causing sore throat and when given at the same daily dose leads to increased hoarseness. There are concerns about adrenal suppression with Fluticasone given to children at doses greater than 400 mcg/day, but the randomised trials included in this review did not provide sufficient data to address this issue.

Adrenal function in children with severe asthma treated with high-dose inhaled glucocorticoids: recommended screening tests in outpatient conditions

BACKGROUND

A number of previous studies have suggested that adrenal suppression occurs in asthmatic children treated with high-doses of inhaled glucocorticoids (IGC). This study was designed to determine the frequency of adrenal suppression in children with severe asthma treated with recommended doses of IGC: namely 500-1,000 microg/day of fluticasone propionate or the equivalent of budesonide (1,000-2,000 microg/day) for a period of at least 12 months.

METHODS

Early morning cortisol (F) and ACTH serum levels were measured in 27 severe asthmatics aged 6-16 years old. The children underwent a low dose ACTH test (1 microg/1.73 m2) with a parallel glucose measurement. Twenty-four hour urine collection was performed before examination for free F (UfF) and creatinine levels. There were no clinical manifestations of adrenal hypofunction in the analyzed children.

RESULTS

Of the 27 patients, 22 had normal basal and post-stimulatory levels of F and normal UfF, and the other five (18.5%) had basal serum F levels of <400 nmol/l. Four of the five also had normal post-stimulatory levels of F and normal UfF. One child had a subnormal peak F value of 484 nmol/l during the ACTH test. None of the patients had a suppressed serum ACTH level, but an elevated ACTH level was found in four children. This study provided biochemical evidence of suboptimal adrenal function in one child in the examined group (3.7%) and a good response to stimulation in all the others, even in those with slightly reduced basal cortisol levels.

CONCLUSION

This study showed that the use of fluticasone in doses of up to 1,000 microg/day (or the equivalent of budesonide) as long-term treatment of children with severe asthma did not substantially affect their adrenal function.

Difficult to control asthma in children

PURPOSE OF REVIEW

The management of children with difficult asthma requires a systematic approach. These children are prescribed high doses of inhaled or oral corticosteroids and a balance must be struck between therapeutic efficacy and side effects. It is important to ensure the diagnosis is correct and that the reasons for poor control in a given child are characterized so that treatment can be targeted for maximal effect.

RECENT FINDINGS

Recent data have demonstrated the correlation between invasive and noninvasive measurement of airway eosinophils. Noninvasive markers of inflammation can be used to determine phenotype and there is increasing evidence on the utility of repeated measures to monitor control and treatment effects. Side effects of high-dose corticosteroids remain a concern. The emergence of new therapies may be of benefit. These are often expensive, however, and have the potential for major side effects. Adherence remains a significant obstacle to the effective management of difficult asthma.

SUMMARY

Children with difficult asthma are a heterogeneous group. Characterization and monitoring of these children can be enhanced by measurements of noninvasive markers of inflammation. Further evaluation of new and phenotype-specific treatments for children with difficult asthma need to be evaluated in prospective randomized controlled trials.

Fatal and near-fatal encephalopathy with hyponatraemia in two siblings with fluticasone-induced adrenal suppression

AIM

To document previously unreported acute effects of adrenal insufficiency.

METHODS

We describe two siblings who presented acutely with hyponatraemia and cerebral oedema following prolonged treatment with high dose inhaled fluticasone.

RESULTS

A girl aged 5.5 years presented with vomiting, headache, visual impairment and seizures. She was hyponatraemic but not hypoglycaemic. Her conscious level continued to deteriorate and she died, post mortem examination showing small adrenal glands and cerebral oedema. Four weeks later her 7-year-old brother presented with similar symptoms. Assessment showed hyponatraemia with cerebral oedema. His illness responded to intensive care. A diagnosis of adrenal insufficiency was made retrospectively in both cases. The siblings had been receiving Fluticasone propionate (FP) in doses of up to 2000 microg/day for several years.

CONCLUSION

We believe that the hyponatraemia and cerebral oedema was related to cortisol deficiency, leading to impaired excretion of water. We emphasize the need for careful cerebral monitoring in acute adrenal insufficiency presenting with impaired consciousness.

Very high dose inhaled corticosteroids: panacea or poison?

Perspective on the paper by Paton et al (see page 808)