Long-term inflammation of the airways with eosinophil infiltration is a hallmark of asthma, even in patients who experience
infrequent symptoms.1 An inhaled corticosteroid (ICS) is the most practical and effective medicine to control
airway inflammation, reduce symptoms and prevent exacerbations in patients with asthma.1 Delivery by inhalation
results in a higher concentration of medicine in the airways and fewer systemic adverse effects than systemic administration
of corticosteroids.2
The mechanism of ICS action
At a molecular level an ICS switches off activated genes that encode for inflammatory proteins such as cytokines, adhesion
molecules and enzymes.1 This results in reduced eosinophil numbers in the airways and sputum, as well as
reductions in the number of activated T cells and mast cells in the airway mucosa.1 Patients with asthma
may experience improvements in symptoms and lung function several days after beginning ICS treatment, however, it may
take a number of months to achieve a maximal reduction in airway hyper-responsiveness.1 Withdrawal of an
ICS is often associated with a deterioration in asthma control.1
No longer current
The New Zealand Asthma Guidelines recommend an ICS for patients at Step 2 in the five-step treatment model for asthma
management (Figure 1).
The optimal point at which to initiate ICS treatment in patients with asthma is not conclusively known. However, following
an assessment of asthma severity (Stage one of the asthma consultation), and the identification of any contributing factors
(Stage two of the consultation), consideration should be given to initiating an ICS for patients not already on this treatment
(Stage three of the consultation).
- The New Zealand Asthma Guidelines recommend beginning ICS treatment when patients have symptoms of asthma on two or
more occasions in the previous week.3
- The Asthma Guidelines also acknowledge that people with less frequent symptoms may benefit from treatment with an ICS
(see: “The START study”).3
- The Global Initiative for Asthma (GINA) recommends initiating an ICS for patients with asthma who require a SABA between
twice a month and twice a week or for those who wake due to asthma symptoms once a month.2
- If the patient has had an asthma exacerbation requiring oral corticosteroids in the past year, this also suggests that
ICS treatment is appropriate.3
Figure 1: The stepwise treatment of adult asthma, adapted from Beasley et al (2016)3
No longer current
Discuss the benefits of ICS treatment and the risks
When considering initiating ICS treatment it is necessary to balance the potential benefits with the reality that
adherence is often poor in people with mild asthma.4 Some patients may judge the inconvenience of daily treatment
and the possibility of adverse effects to be more important than the benefits of early ICS treatment.5 Discuss
any concerns patients might have about ICS treatment (e.g. adverse effects, “steroid stigma”) and where
appropriate reassure them that systemic adverse effects at standard doses are relatively uncommon.
A safety fact sheet for patients taking inhaled corticosteroids is available from the Asthma and Respiratory Foundation:
www.asthmafoundation.org.nz/resources/safety-of-inhaled-corticosteroids-ics
ICS treatment begins with a trial to assess the patient’s response
Treatment with an ICS should begin as a trial with the patient’s response assessed at their next consultation. It is
recommended that a follow-up appointment be scheduled eight weeks after ICS treatment begins.3 Patients with
mild asthma have symptoms that are well controlled with a standard daily ICS dose. Patients with moderate asthma are likely
to require a step up to an ICS/LABA.2
Information on assessing asthma severity is available in: “Managing adults with
asthma in primary care: the four-stage consultation”
The START study
The Steroid Treatment As Regular Therapy (START) study assigned 7,138 patients aged 4 – 66 years with mild asthma, diagnosed
in the past two years, to either once daily budesonide 400 micrograms or placebo. Post-hoc analysis of the START trial
found that budesonide halved the risk of asthma-related adverse events, decreased lung function decline and improved symptom
control across all groups of patients.6 This included patients with symptoms occurring zero to one times per week.6 The
rate of adverse events of patients taking budesonide in START was similar to those taking placebo.7 These results suggest
that many patients with asthma will benefit from earlier initiation of ICS treatment than is recommended by many guidelines.
There is a lack of well designed studies comparing different types of ICS in the treatment of asthma. All ICS subsidised
in New Zealand are broadly considered to be equally effective when taken at clinically equivalent doses, i.e. beclomethasone
dipropionate and budesonide are approximately equivalent to fluticasone propinonate taken at half the dose.5 Patient
preference for inhaler devices and clinical experience are the main factors in determining ICS selection.
Choosing a starting dose for an ICS
Patients with asthma can begin treatment with an ICS at a standard dose (Table 1).3 The term “standard
dose” has replaced the term low dose that was used in previous guidance. Standard doses provide patients with 80 – 90%
of the maximum obtainable benefit of ICS treatment.3 It is recommended that ICS be initiated with twice daily
dosing, as this is slightly more effective than once daily dosing.5
“Stepping up” asthma treatment
Patients who do not have adequate symptom control after an eight-week trial with a standard ICS dose may require a longer
period to determine if they will respond to ICS treatment or they may be switched to an ICS/LABA combination inhaler.3 The
ICS component of combination treatment may be increased once the patient’s response to an ICS/LABA has been assessed.
Information on initiating LABA treatment is available in the article “Adding a
LABA to asthma treatment for adults”
Table 1: Recommended clinically equivalent standard daily doses of ICS for adults with asthma8, 9
Type of ICS and standard starting dose |
Dose per inhalation (micrograms) |
Patients should take |
Subsidised brand and inhaler type |
Beclomethasone dipropionate 400 – 500 micrograms/day |
50 |
Four inhalations, twice daily |
Beclazone metered dose inhaler (MDI) |
100 |
Two inhalations, twice daily |
250 |
One inhalation, twice daily |
Beclomethasone dipropionate extrafine* 200 micrograms/day |
50 |
Two inhalations, twice daily |
Qvar MDI |
100 |
One inhalation, twice daily |
Budesonide 400 micrograms/day |
100 |
Two inhalations, twice daily |
Pulmicort dry powder inhaler (DPI) |
200 |
One inhalation, twice daily |
400 |
One inhalation, once daily |
Fluticasone propionate 200 – 250 micrograms/day |
50 |
Two inhalations, twice daily |
Flixotide DPI, Flixotide and Floair MDIs |
100 |
One inhalation, twice daily |
Flixotide DPI |
125 |
One inhalation, twice daily |
Flixotide and Floair MDIs |
*Aerosol droplets are on average approximately ten times smaller than droplets in beclomethasone dipropionate
Treatment with an ICS can cause local or systemic adverse effects. At standard doses the risk of clinically significant
adverse effects is relatively low, although the risk is increased in patients who are also taking potent topical corticosteroids.5 At
standard doses dysphonia and oral candidiasis are the most common adverse effects of ICS treatment.5 Oral
rinsing after taking an ICS reduces the risk of ICS-related adverse effects.2 It is advisable to check the
inhaler technique of any patient who may be experiencing adverse effects. Poor inhaler technique is associated with an
increased risk of: poor asthma control, hospitalisation, courses of oral steroids and use of antibiotics.10 Errors
that are frequently seen in patients using inhalers include not holding their breath after an inhalation, inhaling too
early, not exhaling before actuation and not shaking the inhaler.10
The extent of systemic ICS absorption is dependent on the inhaler device, particle size, deposition and the individual
properties of the active ingredient.11 Anxiety, depression, sleep disturbances, behavioural changes, e.g.
hyperactivity and irritability, hyperglycaemia, skin thinning and bruising have been reported in patients taking inhaled
corticosteroids.12 There may also be a small increased risk of glaucoma in some patients.12 Hypersensitivity
reactions, e.g. rash and angioedema, to ICS treatment are uncommon and paradoxical bronchospasm is a very rare adverse
event.12 A reduction in bone mineral density following long-term ICS use at high doses may increase the risk
of osteoporosis in some patients.12 There is no clear guidance on when to consider a bisphosphonate for a
patient taking long-term high-dose ICS,13 however, this decision can be guided by a risk assessment including
the patient’s age, history and results of dual-energy X-ray absorptiometry (DEXA).
“Stepping down” the ICS regimen
The risk of ICS-related adverse effects can be decreased by reducing the dose. This may be appropriate for patients
with asthma symptoms that have been well-controlled for three months who have a low exacerbation risk.3 A
50% ICS dose reduction can be trialled, regardless of the patient’s starting dose and dose tapering is not required. This
can be achieved by either:
- Halving the number of inhalations, e.g. beclomethasone dipropionate, 100 micrograms TWO inhalations twice daily
is reduced to ONE inhalation, twice daily; or
- Taking an ICS only in the evening, e.g. budesonide* 400 micrograms, daily (two inhalations of a 100 microgram
inhaler, twice daily) becomes budesonide 200 micrograms, daily (two inhalations of a 100 microgram
inhaler, in the evening).
* Budesonide is the only ICS subsidised in New Zealand that is licensed for once-daily dosing.12
Complete withdrawal of ICS treatment is not recommended,3 as this is likely to result in an exacerbation.
However, a temporary withdrawal may be appropriate for patients with seasonal symptoms with treatment resuming at the
first onset of symptoms.