Disodium cromoglycate use in children and adolescents with asthma: correlation between plasma concentrations and protective effects for various inhalation methods

A simple pharmacokinetic method to evaluate the pulmonary dose in clinical practice—analyses of inhaled sodium cromoglycate

When the expected effect of an inhaled drug is not achieved, the cause could be poor inhalation technique and consequently a low pulmonary dose. A simple in vivo test to evaluate the pulmonary dose would be a benefit. This study evaluates the relative and systemic bioavailability following inhalation of nebulized sodium cromoglycate (SCG) in healthy subjects. Blood samples were collected during 240 min and urine was collected in two portions, up to 6 h post-inhalation. Two exposures were performed and comparisons based on the quantification of drug in plasma and urine by a high-performance liquid chromatography (HPLC) procedure were done. In one of the exposures, a pulmonary function test was performed to study if an expected effect of increased absorption could be detected. There was a good correlation between the two exposures shown in the plasma concentrations, but not in the urine analyses. The forced exhaled volume manoeuvres were associated with a higher Cmax and plasma concentrations up to 60 min post-inhalation (P<0.01). This effect was not detected in the urine analyses. We conclude that this pharmacokinetic method with inhaled SCG and plasma analyses could be used to evaluate individual inhalation technique. The HPLC method used was rapid and had adequate sensitivity.

Anti-inflammatory treatment for recurrent wheezing in the first five years of life

Medications identified for the treatment of recurrent wheezing in preschool children by the Expert Panel Report of the NHLBI Guidelines for the Diagnosis and Management of Asthma include inhaled corticosteroids, chromones, theophylline, and leukotriene pathway modifiers. However, these various agents differ in their mechanism, extent of action on the airway inflammatory process, and degree of clinical efficacy. Inhaled corticosteroids can control symptoms in many young children with even severe persistent wheezing, but data on their long-term safety when administered in preschool-age children are scarce. There is some information on the uninterrupted use of inhaled corticosteroids in school-age children and the absence of an adverse effect on ultimate adult height. Despite laboratory evidence of adrenal suppression in some studies, few pediatric cases of clinical adrenal insufficiency have been reported. Low-dose inhaled corticosteroid (<400 mcg/day for beclomethasone), which is adequate for controlling mild persistent symptoms, is generally safe. Chromones have a remarkable safety profile, but they are most effective for symptoms of mild severity. Promising data have been published on the efficacy and safety of leukotriene pathway modifiers when used in young children with persistent symptoms. It is uncertain whether early introduction and long-term administration of inhaled corticosteroids prevent development of irreversible airway obstruction. Nevertheless, they may be especially useful for patients with moderate to severe disease in whom other agents (chromones or leukotriene pathway modifiers) will most likely fail to control symptoms. Pediatr Pulmonol. 2003; 35:241-252.

Long-term management of asthma

Long-term management of asthma includes identification and avoidance of precipitating factors of asthma, pharmacotherapy and home management plan. Common precipitating factors include viral upper respiratory infections, exposure to smoke, dust, cold food and cold air. Avoidance of common precipitating factors has been shown to help in better control of asthma. Pharmacotherapy is the main stay of treatment of asthma. Commonly used drugs for better control of asthma are long and short acting bronchodilators, mast cell stabilizers, inhaled steroids, theophylline and steroid sparing agents. After assessment of severity most appropriate medications are selected. For mild episodic asthma the medications are short acting beta agonists as and when required. For mild persistent asthma: as and when required bronchodilators along with a daily maintenance treatment in form of low dose inhaled steroids or cromolyn or oral theophylline or leukotriene antagonists are required. Moderate persistent asthma should be treated with inhaled steroids along with long acting beta agonists for symptom control. For severe persistent asthma the recommended treatment includes inhaled steroids, long acting beta agonists with or without theophylline. If symptoms are not well controlled, a minimal dose of oral prednisolone preferably on alternate days may be needed in few patients. Patients should be followed up every 8-12 weeks. On each follow up visit patients should be examined by a doctor, compliance to medications should be checked and actual inhalation technique is observed. Depending on the assessment, medications may be decreased or stepped up. For exercise induced bronchoconstriction: cromolyn, short or long acting beta agonists or leukotriene antagonists may be used. In children with seasonal asthma, maintenance treatment according to assessed severity should be started 2 weeks in advance and continued throughout the season. These patients should be reassessed after discontinuing the treatment. Parents should be given a written plan for management of acute exacerbation at home.