 Despite what his doctor keeps telling him, 23-year-old
Jessie P only uses his budesonide inhaler when his asthma
symptoms flare up. Using his salbutamol inhaler a few
times a week when he's a bit wheezy seems to keep things
under control. Jessie prefers to use medication only when
absolutely necessary because he isn't convinced that inhaling
steroids every day is good for his health. Plus, he says
he couldn't afford to take his medication twice a day
even if he wanted to.
Based on prescription patterns,
Jessie isn't alone. About 50% of asthma patients have
mild-to-moderate disease and most of them only use their
preventive therapy intermittently, not daily as current
guidelines recommend. A study published in the April
14 issue of the New England Journal of Medicine (NEJM)
supports this trend. The research suggests that using
inhaled corticosteroids (ICS) on an as-needed basis
may actually be an effective way to treat mild cases
of asthma. Another study in The Journal of Allergy
and Clinical Immunology goes so far as to say that
certain patients with mild-to-moderate persistent asthma
can get rid of their inhalers for good.
BACK
IT UP
"[The NEJM] study will need confirmation before
the findings should change the standard of practice,
but it suggests that adults with mild asthma may do
about as well if they have the medication on hand and
are advised to take them for a week or two just when
their symptoms flare up," said study co-leader Dr Homer
Boushey from the University of California, San Francisco,
in a public statement.
The double-blind NEJM trial
included 225 adults with mild persistent asthma recruited
from six major medical centres across the US. All study
participants followed a "symptom-based action plan"
to treat exacerbations using intermittent high-dose
ICS. Participants were also randomly assigned to one
of three daily treatment groups: placebo (symptom-based
intermittent therapy only), inhaled steroid (daily budesonide
plus intermittent therapy) or oral leukotriene-receptor
antagonist (daily zafirlukast plus intermittent therapy).
The primary outcome measure was
the change in morning peak expiratory flow (PEF) over
the one-year study period. PEF was chosen because it's
a very reliable indicator of airflow obstruction. Other
outcome measures included frequency of exacerbations,
quality of life, number of symptom-free days, degree
of asthma control and "other objective measures of lung
function and airway biology."
PEAK
PERFORMANCE
Surprisingly, no significant difference in morning PEF,
frequency of exacerbations requiring prednisone, or
asthma-related quality of life was found between the
three groups. This means that symptom-based intermittent
corticosteroid therapy was as effective as daily steroid
therapy in providing relief.
However, the number of symptom-free
days, as well as the improvement in asthma control and
"other objective measures" were significantly greater
in the group taking budesonide every day.
"Whether the increase in symptom-free
days is worth the costs of treatment, both fiscal and
with respect to longterm side effects, may be an individual,
subjective judgment best left to the patients and his
or her healthcare provider," conclude Dr Bouchy and
his colleagues. "Our study shows that for mild asthma,
at least for the short term, this 'folk wisdom' is a
safe practice," advises Dr Bouchy.
LOSE
IT ALL TOGETHER
New research takes this trend one step further and suggests
that some patients may not even need their ICS therapy.
"A large number of clinically stable mild-moderate asthmatic
patients using inhaled corticosteroids could discon-
tinue these medications without an increased risk of
deteriorating asthma control," claims Dr Aaron Deykin,
lead author of a new asthma control study published
in the April issue of The Journal of Allergy and
Clinical Immunology.
But how can physicians correctly
identify asthma patients who can safely discontinue
ICS therapy? The new study suggests doctors should think
like dentists, and ask asthma patients to rinse out
their mouths and spit some sputum into a cup for a quick
eosinophil count.
Dr Deykin and his research team
compared three non-invasive markers of inflammation
— exhaled nitric oxide, methacholine bronchial
provocation and induced sputum eosinophil counts —
to predict asthma progression after discontinuing ICS.
The findings were part of the
multi-centre Asthma Clinical Research Network's Salbutemol
or Corticosteroids (SOCS) trial. The 164 SOCS participants
were clinically stable non-smokers with mild-to-moderate
asthma, using only ICS for asthma control. The patients
first received open-label triamcinolone acetonide (TAA)
twice daily for a six-week period. Patients who remained
stable on TAA were then randomized to double-blind placebo
therapy, long-acting salmeterol twice daily and TAA
placebo, or TAA twice daily and a placebo for 16 weeks.
JUST
SPIT IT OUT
During the 16-week test period, 24.1% of patients who
switched from ICS to salmeterol and 37.5% of those who
switched to a placebo experienced a worsening of their
asthma symptoms. Only 9.3% of subjects who continued
on ICS therapy got worse. So how can you tell which
of your patients can afford to ditch the ICS therapy
without risking their health? The researchers discovered
"the change in the percentage of eosinophils in induced
sputum during the first two weeks after ICS cessation
is a useful predictor of subsequent deterioration of
asthma control." Neither exhaled nitric oxide nor methacholine
bronchial provocation accurately predicted asthma control
after discontinuing ICS.
Strategic use of sputum eosinophil
counts could allow up to 48% of mild-to-moderately asthmatic
patients to quit ICS therapy without any worsening of
their condition, while reducing medication costs and
side effects. According to the authors, patients whose
sputum eosinophil counts increased by 0.8% or less in
the first two weeks after stopping ICS would remain
stable without their meds; those with greater increases
in eosinophil counts will need to stay on their ICS.
The authors maintain this selective
medication strategy could provide overall asthma control
equivalent to that obtained when all patients are treated.
But Dr Deykin notes sputum eosinophil counting is used
mainly in research and is not widely available in clinical
practice — yet.
Until sputum eosinophil counts
are more widely available to MDs, Dr Deykin cautions
practitioners to "proceed very cautiously when reducing
the dose of inhaled corticosteroids without the aid
of sputum analysis. Only those patients with clinically
stable mild-moderate disease should be considered and
these patients should be followed closely for evidence
of deteriorating control."
NEJM Apr 14, 2005;352(15):1519-28
J Allergy Clin Immunol Apr 2005;115(4):720-7
|
