A comparison of the efficacy and safety of inhaled corticosteroids in asthma

Stressors and concerns in teen asthma

Adolescents are uniquely susceptible to poor outcome with asthma because of their desire for autonomy, denial of disease, preference for immediate gain rather than prophylaxis, restricted ability to control their psychosocial and physical environment, and difficult transition to health care. Tobacco smoking as well as related drug abuse and passive exposure to tobacco is a major obstacle to managing adolescent asthma, together with atopy and psychosocial problems. Recent investigations indicate that adolescents are uniquely susceptible to tobacco industry promotions and logos because of these developmental characteristics. By understanding adolescent development, behavior and peer group impact, with its spectrum from early to late adolescence, clinicians can target their educational interventions more successfully in asthma. Health care provision for the adolescent with asthma requires a multidisciplinary team spearheaded by a primary care provider with the expert guidance of an allergist, outreach nurse, mental health worker, and social service representative. This care must be negotiated with an appropriate educational plan on the basis of NHLBI guidelines to be successful. Medications should be prescribed no more than twice a day, whenever possible, in conjunction with an action plan on the basis of peak flow readings to warn the adolescent when to use more medication and when to call the clinician. The plan should empower adolescents by recognizing their need for autonomy with self-management, enabling them to have a safe and comfortable lifestyle, and being physically and mentally at ease with their peers, family, school, and work environments.

Inhaled corticosteroids for adult asthma: impact of formulation and delivery device on relative pharmacokinetics, efficacy and safety

Metered dose inhalers (MDIs) are the mainstay of inhaled steroid therapy for asthma. With the phasing out of traditional chlorofluorocarbon (CFC) propellants and their replacement with a new generation of CFC-free products, it is becoming clear that formulation and inhaler characteristics can markedly affect the drug delivery. It now seems necessary to compare inhalers not only on the basis of the properties of the steroid molecules but also to take into account the effect of propellants and other inhaler characteristics. The impact of formulation and delivery device on relative pharmacokinetics, therapeutic efficacy and tolerability is illustrated by a new preparation of beclomethasone dipropionate (BDP) in an inhaler containing hydrofluoroalkane (HFA) propellant, called Qvar (3M Health Care, U.K.). This drug preparation delivers the majority of particles (60%) in the fine particle range. This appears to be associated with improved lung deposition, a halving of dose requirements of BDP, but no evidence of clinically relevant adrenal suppression when used in therapeutic doses. Prescribers need to be aware of the impact of formulation on pharmacokinetics of inhaled steroids in order to offer the lowest effective dose and give clear instructions to patients who are changing to a CFC-free product.

The effect of intranasal and inhaled corticosteroids in healthy volunteers on the number of circulating lymphocytes and lymphocyte subsets

BACKGROUND

There has been an increasing interest in the potential systemic effects of inhaled corticosteroids.

METHODS

The effect of locally inhaled corticosteroids in the nose and lung on blood lymphocytes was measured in two studies. In the first study, budesonide (BUD) (200 and 800 microg), fluticasone propionate (FP) (200 and 800 microg), and placebo were administered in the nose, and BUD (1600 microg) and FP (1500 microg) were inhaled into the lungs in a blinded, randomized fashion by 12 healthy volunteers. Blood samples were taken before and 4 h after the administration of the drug, and total lymphocyte count and different subpopulations were determined. In the second study, 15 healthy volunteers were randomized to BUD (1600 microg), FP (1600 microg), or placebo inhaled into the lungs. Blood samples were taken before and 4, 8, 24, 48, and 148 h (=7 days) after inhalation of the medication.

RESULTS

Neither the nasal applications nor the inhalation of FP (1500 microg/1600 microg) showed significant differences in total lymphocyte count or different subpopulations between baseline and 4 h after the administration. In both studies, a significant reduction was found in the total lymphocyte count, B cells, T cells, and the CD4+ and the CD8+ fractions 4 h after application of BUD 1600 microg.

CONCLUSIONS

Nasal application of BUD or FP in doses up to 800 microg do not induce lymphopenia. BUD 1600 microg inhalation in the lung reduces lymphocytes and their subfractions. Further studies have to be done to determine whether the results obtained in this study in healthy volunteers will also be found in patients with diseased mucosa and whether there is any correlation with adverse effects such as growth inhibition or osteoporosis.

Establishing a therapeutic index for the inhaled corticosteroids: part I. Pharmacokinetic/pharmacodynamic comparison of the inhaled corticosteroids

The inhaled corticosteroids contain physicochemical differences that alter both glucocorticoid receptor-binding characteristics and the pharmacokinetic variables of these drugs. Differences in receptor-binding affinity translate into differences in potency for different drugs. Differences in pharmacokinetics, however, determine the topical effect to systemic effect ratio, or the "pulmonary targeting" of the drug. Beneficial pharmacokinetic properties that may improve pulmonary targeting include low oral bioavailability, rapid systemic clearance, and slow absorption from the lung. Delivery devices can produce clinically significant differences in topical activity by altering the dose deposited in the lung and, for orally absorbed drugs, the amount deposited in the oropharynx and swallowed. Clinical trials have confirmed that differences in potency or drug delivery of 2-fold or more can be detected in patients with asthma. However, because of the relatively flat nature of the dose-response curve for morning peak expiratory flow and forced expiratory volume in 1 second, the trials must be adequately powered and well controlled. The use of bronchial provocation measures are problematic because of the prolonged lag time for response. Study design flaws can lead to misinterpretation of results. Clinical studies have indicated the following relative potency differences: fluticasone propionate > budesonide = beclomethasone dipropionate > triamcinolone acetonide = flunisolide. Current evidence suggests that potency differences can be overcome by giving larger doses of the less potent drug. However, because of these potency differences, studies of systemic effects should not be done in isolation of adequate topical activity studies to define the pulmonary targeting of the drugs.

A UK Consensus Group on management of glucocorticoid-induced osteoporosis: an update

In the UK, over 250 000 patients take continuous oral glucocorticoids (GCs), yet no more than 14% receive any therapy to prevent bone loss, a major complication of GC treatment. Bone loss is rapid, particularly in the first year, and fracture risk may double. This review, based wherever possible on clinical evidence, aims to provide easy-to-use guidance with wide applicability. A treatment algorithm is presented for adults receiving GC doses of 7.5 mg day(-1) or more for 6 months or more. General measures, e.g. alternative GCs and routes of administration, and therapeutic interventions, e.g. cyclical etidronate and hormone replacement, are recommended.

Osteoporosis in the corticosteroid-treated patient with asthma

Osteoporosis affects 40% of white women older than 45 years of age and 15% of white men older than 50 years of age, resulting in approximately 1.5 million annual fractures in the United States. Systemic corticosteroid therapy increases the probability of osteoporosis, even with alternate-day dosing and with dosages sufficiently low so as not to affect the hypothalamic-pituitary-adrenal axis. Inhaled corticosteroid therapy may affect bone density if high-dose therapy is given to select individuals. The potential of increasing osteoporosis with inhaled corticosteroid asthma therapy is a concern because of the availability of more potent inhaled corticosteroid agents and recommendations that inhaled corticosteroid therapy be initiated earlier in the course of asthma. This article provides suggestions, on the basis of the medical literature and consensus of the authors when specific information was not available, for assessing and treating osteoporosis in subjects with asthma. Suggested risk categories are "low risk" (inhaled corticosteroid dosage of < or =800 microg of heclomethasone dipropionate [BDP]/day in adults or < or =400 microg BDP or equivalent in children), "moderate risk" (inhaled BDP >800 microg/day in adults or >400 microg/day in children), and "high risk" (systemic corticosteroid therapy 4 times a year or daily or alternate-day systemic corticosteroid therapy). Dosage of nasal corticosteroid probably should be added to the orally inhaled corticosteroid for total burden of inhaled corticosteroid. Potential treatment strategies based on risk factors and bone density if indicated are offered to assist physicians treating patients with asthma.