Wednesday, April 24, 2013

One Inhaler or Two?

In the U.S. most persons with more than occasional symptoms of asthma have two inhalers: one taken regularly to suppress airway inflammation and prevent asthmatic attacks, the other to be used “as needed” when symptoms of asthma flare.  One is the “controller,” the other the “quick-reliever.”  In most instances, the controller inhaler provides no immediate relief of asthma symptoms, and the quick–reliever inhaler provides no long-term benefit to quiet the inflamed airways. 
One can quickly see the potential for confusion.  “Which inhaler did the doctor say I should take every day, which one only when I was short of breath or wheezing?”  The two inhalers may look virtually identical, except for color.  For other people, the complexity relates to two different types of inhalers.  In the U.S. all of our quick-relievers come in the form of metered-dose inhalers – a metal canister in a plastic holder from which a short “puff” of medication is released.  However, the controller inhalers may take the form of dry-powder inhalers, which require a forceful inhalation to pull the powdered medication from its canister.  Then there is the issue of frequency of use: most controller inhalers are meant to be taken once or twice a day and no more; the quick-reliever can be used up to four times a day and even more often in an acute crisis.

What if ….?  What if there were one inhaler that could be used both as a controller and as a quick-reliever, for maintenance and for rescue?  One device, one technique to be mastered in order to inhale the medication optimally.  Use it once or twice to a day to keep your asthma quiet, use extra doses from the same inhaler if you find yourself short of breath or wheezing.  Such an inhaler, containing a combination of two medications, is available … although in the U.S. it is not recommended for use in this way … yet.
What made this single inhaler for both maintenance and rescue possible was the development of a bronchodilator that both exerts its effect quickly (within 3-5 minutes) and also maintains its effect all day (or night) long.  This medication is the long-acting bronchodilator, formoterol, which works for at least 12 hours to hold open the bronchial tubes, but with an additional dose acts as a quick-reliever.  It is combined with an inhaled steroid in the two inhalers, Symbicort and Dulera.  Symbicort combines formoterol with the anti-inflammatory steroid, budesonide; Dulera combines formoterol with the anti-inflammatory steroid, mometasone. 

Taken every day, these combination steroid/long-acting bronchodilator inhalers can keep asthma under good control.  If asthma flares up, additional doses provide quick relief and at the same time escalate the amount of controller medication, until asthma again quiets.  A recent study published in Lancet Respiratory Medicine confirmed prior reports that this approach is effective and, in the long run, may help to keep the dose of inhaled steroids as low as possible, which is a good thing.
So why have U.S. physicians not embraced this approach?  First and foremost is the lingering concern, previously discussed in this blog (see "The Contoversy That Won't Go Away"), that in some patients long-acting bronchodilators like formoterol may on rare occasion lessen asthma control and cause severe, even fatal asthma attacks.  Although some would argue that the long-acting bronchodilators are potentially dangerous only when used without an accompanying inhaled steroid, definitive research to test this hypothesis is currently being conducted and the results are years away.  Other concerns relate to potential side effects from overuse of a long-acting bronchodilator: if jitteriness or heart racing develops, the side effect will likely last for many hours. 

We do not anticipate that practice will change in the U.S. any time soon.   For now, we are committed to two separate inhalers: one used regularly for control of asthma; one taken as needed for quick relief of troublesome symptoms.  But depending on the results of current research into the long-term safety of long-acting bronchodilators when combined with an inhaled steroid, a small revolution in asthma care may be coming down the road.