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PULMONOLOGY
3.1.5 Other long term
treatment options
Immunotherapy
Consider
stepping down
when asthma
symptoms
have been well
controlled and
lung function
has been stable
Allergen immunotherapy should
be considered for patients
who have persistent asthma
if there is clear evidence
of a relationship between
symptoms and exposure to an
allergen to which the patient is
sensitive.
Both subcutaneous and
sublingual immunotherapy
has an effect on inflammatory
parameters and bronchial
hyperreactivity in asthmatics
sensitised to house dust mites.
Sublingual immunotherapy is
the safer option and could be
used as adjunctive treatment to
pharmacotherapy in adults and
children older than five years
old with rhinitis and mild to
moderate asthma (FEV1 >80%),
to enhance asthma control.
Immunosuppressives
including methotrexate may
rarely be of benefit in refractory
asthmatics. Patients considered
for this treatment must be
referred to a specialist.
Antihistamines are ineffective
in the treatment and prevention
of asthma.
Dietary changes
There is little scientific evidence
that exclusion diets are useful
in the treatment of asthma.
As such, they are not routinely
recommended.
Several cross-sectional
studies have shown that low
serum levels of Vitamin D
are linked to impaired lung
function, higher exacerbation
frequency and reduced
corticosteroid response.
However, to date, Vitamin D
supplementation has not been
associated with improvement in
asthma control or reduction in
exacerbations.
4. “Newer” treatment
modalities for asthma
4.1 Long Acting
Anti-Cholinergics
Tiotropium bromide is
an inhaled, once daily
anticholinergic bronchodilator
which binds to all three
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May 2017
muscarinic receptors to
produce a long acting
bronchodilator effect and
possibly an anti-inflammatory
effect. It was initially approved
for COPD, but recently (2015)
added on as a late step in adult
chronic asthma guidelines as
a treatment option in patients
with uncontrolled asthma
despite high doses of inhaled
corticosteroids and LABAs.
Tiotropium is available as a
dry powder inhaler or pMDI,
and is licensed for adults
and adolescents over the age
of 12 years in a once daily
dose. Studies have shown
an improvement in lung
functions and a reduction in
exacerbations in patients with
uncontrolled asthma.
4.2 Monoclonal antibodies
4.2.1 Omalizumab (anti IgE)
Omalizumab is a recombinant
humanised monoclonal anti-
IgE antibody. It binds free IgE in
blood and interstitial fluid and
to the membrane-bound form
of IgE on the surface of mIgE-
expressing B-lymphocytes.
It is licensed as an add-on
treatment in severe persistent
asthma in adults, adolescents
and children over the age of
six years with evidence of
allergic sensitisation and IgE
levels of up to 1500 kU/L.
There is also some evidence
for its efficacy at higher IgE
levels. Studies have shown
improvement in quality of life
as well as reductions in severe
exacerbations in patients on
omalizumab. Omalizumab is
given subcutaneously every 2-4
weeks and courses of at least
six months are recommended
for severe asthma in suitable
patients.
4.2.2 Mepolizumab
(anti interleukin-5)
Mepolizumab is a fully
humanised anti-interleukin 5
(IL-5) monoclonal IgG1 antibody
that binds to free IL5 and
prevents its association with
the IL5 receptor on eosinophils.
In clinical trials it has been
shown to reduce airways
and blood eosinophils and
reduce asthma exacerbations.
Mepolizumab has recently
been added on to the step-up
guidelines for severe asthma
uncontrolled on high dose
inhaled steroids and LABAs. It
should be given in specialist
referral centres only and is
licensed for over the age of 12
years.
4.2.3 Dupilumab (anti
interleukin 4)
Dupilumab is a fully human
monoclonal antibody directed
against the body’s interleukin
(IL)-4 receptors, intended
to inhibit the downstream
effects of type 2 mucosal
immunity cytokines, IL-4
and IL-13. Both are cytokines
believed to play a major role
in the manifestation of allergic
diseases. Studies have shown
dupilumab to be efficacious
as an add-on therapy to
medium-to-high-dose inhaled
corticosteroids plus a long-
acting β 2 agonist in patients
with uncontrolled persistent
asthma. Improvement has
been demonstrated in baseline
forced expiratory volume in 1 s
(FEV 1 ), as well as a reduction in
annualised exacerbation rates
and improvements in quality
of life and asthma control.
Efficacy was more evident
when injections were given
every two weeks compared
with every four weeks.
Treatment algorithms for the
management of chronic asthma
in accordance with GINA (Global
Initiative for Asthma) guidelines
2016 are advised.
5. Stepping down
asthma treatment
Consider stepping down when
asthma symptoms have been
well controlled and lung
function has been stable
for three or more months.
This should be done under
close supervision. Asthma is
considered well controlled if:
» ≤ 2 daytime symptoms/week
» No limitation of activities
» No nocturnal symptoms/
awakenings
The Specialist Forum | Vol. 17 No. 4