Choosing the Right Asthma Therapy for Children - Brief Article - Statistical Data Included

0 Comments | Family Practice News, Jan 1, 2000 | by Mike Bykowski

BALTIMORE -- Selecting the right medication or medications for children with asthma can be a daunting task, Dr. Robert A. Wood said at a pediatric meeting sponsored by Johns Hopkins University.

The field of asthma treatment is rapidly changing, and it can be confusing, said Dr. Wood, a pediatric allergist at Johns Hopkins.

Appropriate use of asthma therapies will hopefully help reverse the trend of increasing morbidity and mortality associated with the condition in children, he said.

Based on his experience, Dr. Wood described when and how to use some of the currently available pediatric asthma therapies:

* Salmeterol. Salmeterol (Serevent) is a long-acting inhaled [b.sub.2]against approved for use in children as young as 4 years.

Salmeterol "really fits into the meat of the pediatric asthma group," he said.

"It is clearly advantageous as an additive therapy to another maintenance drug like an inhaled steroid, it clearly has benefit for the prophylaxis of exercise-induced asthma, and because of its very long duration of action, it is a wonderful product for the control of nocturnal asthma," he said.

While salmeterol isn't the sole remedy for nocturnal asthma, "it will most likely take your patients through the night without them developing any cough or wheezing that may be disturbing their sleep," Dr. Wood said.

Salmeterol is not an appropriate monotherapy for asthma, he said.

* Levalbuterol. This albuterol variant has a longer duration of action than albuterol, 6-8 hours compared with 4-6 hours. It also produces a modest increase in bronchodilitation compared with albuterol and has fewer side effects, he said.

Patients who have significant side effects with albuterol are good candidates for 1evalbuterol. However, "the advantages in terms of bronchodilitation and duration of action are not overwhelming enough for me to be prescribing it for all my patients taking nebulized albuterol," he said.

Levalbuterol (Xopenex) is currently approved for use in children as young as 12 years, but he anticipates that it will be approved in children as young as age 4 in the next few years.

Levalbuterol is considerably more costly than albuterol, "even if you factor in the fact that fewer doses may be needed," Dr. Wood said.

* Leukotriene Antagonists. Three of these agents are on the market now: montelukast (Singulair), zafirlukast (Accolate), and zileuton (Zyflo). Montelukast is approved for age 6 and above, zafirlukast is approved for age 7 and above, and zileuton is approved for age 12 and above.

Whether these drugs are truly anti-inflammatory agents is still somewhat controversial, Dr. Wood said. "They have not received a label as anti-inflammatory drugs, but by their action on inflammatory outcomes, they dearly have some effect on the inflammatory cascade in asthma."

The leukotriene antagonists are about as potent as cromolyn but less potent than the topical steroids. Montelukast and zafirlukast have much better efficacy to toxicity ratios than zileuton, he said.

One potential use is as a maintenance therapy, but "we're mostly using these drugs as an additive therapy to another anti-inflammatory agent when patients are not adequately controlled on an inhaled steroid," he said.

They are most effective at controlling exercise- and aspirin-induced asthma.

The leukotrienes are oral medications given once or twice daily so they may improve compliance, he said.

* Corticosteroids. The corticosteroids fluticasone (Flovent), budesonide (Pulmicort Turbuhaler), beclomethasone (Beclovent, Vanceril), triamcinolone (Azmacort), and flunisolide (Aerobid) have the greatest ability of all the pediatric ashma drugs to reduce airway inflammation, Dr. Wood.

"They are the most effective prophylactic medications for asthma, particularly in those with moderate to severe disease, and their early use has been shown to prevent disease progression, even for patients with mild asthma," he said.

The newer inhaled steroids, fluticasone and budesonide, have considerably greater anti-inflammatory activity compared with the older inhaled steroids. Fluticasone is the most potent topical corticosteroid currently available and is also among the least toxic, he said.

Low doses of inhaled corticosteroids should be prescribed for patients with mild persistent asthma. (See chart.) At these doses, all of these drugs are probably very safe, he said.

Medium doses should be prescribed for patients with moderate persistent asthma, but these dosages are going to have some definite relationship to toxicity and may affect linear growth.

High doses of corticosteroids should be reserved for only the most severe cases; systemic toxicity becomes a real concern with use of this amount of steroid, Dr. Wood said.

Dr. Wood has received financial support from AstraZeneca, Glaxo Pharmaceuticals, Merck, and Schering.

                  Estimated Comparative Daily Dosages of
               Inhaled Corticosteroids in Asthmatic Children
Drug                                 Low Dose
Beclomethasone dipropionate          84-336 [micro]g
 42 [micro]g/puff                    (2-8 puffs = 42 [micro]g)
 84 [micro]g/puff                    (1-4 puffs = 84 [micro]g)
Budesonide                           100-200 [micro]g
 DPI: 200 [micro]g/dose [*]
Flunisolide                          500-750 [micro]g
 250 [micro]g/puff                   (2-3 puffs)
Fluticasone                          88-176 [micro]g
 DPI: 50, 100, 250 [micro]g/dose [*] (2-4 inhalations = 50 [micro]g)
 MDI: 44, 110, 220 [micro]g/puff [*] (2-4 puffs = 44 [micro]g)
Triamcinoline acetonide              400-800 [micro]g
 100 [micro]g/puff                   (4-8 puffs)
Drug                                 Medium Dose
Beclomethasone dipropionate          336-672 [micro]g
 42 [micro]g/puff                    (8-16 puffs = 42 [micro]g)
 84 [micro]g/puff                    (4-8 puffs = 84 [micro]g)
Budesonide                           200-400 [micro]g
 DPI: 200 [micro]g/dose [*]          (1-2 inhalations = 200 [micro]g)
Flunisolide                          1,000-1,250 [micro]g
 250 [micro]g/puff                   (4-5 puffs)
Fluticasone                          176-440 [micro]g
 DPI: 50, 100, 250 [micro]g/dose [*] (2-4 inhalations = 100 [micro]g)
 MDI: 44, 110, 220 [micro]g/puff [*] (4-10 puffs = 44 [micro]g) OR
                                     (2-4 puffs = 110 [microl]g)
Triamcinoline acetonide              800-1,200 [micro]g
 100 [micro]g/puff                   (8-12 puffs)
Drug                                   High Dose
Beclomethasone dipropionate            [greater than]672 [micro]g
 42 [micro]g/puff                      ([greater than]16 puffs = 42 [micro]g)
 84 [micro]g/puff                      ([greater than]8 puffs = 84 [micro]g)
Budesonide                             [greater than]400 [micro]g
 DPI: 200 [micro]g/dose [*]            ([greater than]2 inhalations = 200
                                       [micro]g)
Flunisolide                            [greater than]1,250 [micro]g
 250 [micro]g/puff                     ([greater tahn]5 puffs)
Fluticasone                            [greater than]440 [micro]g
 DPI: 50, 100, 250 [micro]g/dose [*]   ([greater than]4 inhalations = 100
                                       [micro]g) OR
                                       ([greater than]2 inhalations = 250
                                       [micro]g)
MDI: 44, 110, 220 [micro]g/puff [*]    ([greater than]4 puffs = 110 [micro]g)
                                       OR
                                       ([greater than]2 puffs = 220 [micro]g)
Triamcinoline acetonide                [greater than]1,200 [micro]g
 100 [micro]g/puff                     ([greater than]12 puffs)
(*.)DPI = Dry-Powder Inhaler; MDI = Metered-Dose Inhaler.
Some dosages may be outside labeling.
Source: National Heart, Lund, and Blood Institute's National Asthma
Education and Prevention Program, 1997