GPs told to up steroids in asthmatic smokers
New SIGN/BTS guidelines warn smokers are resistant to treatment
Many patients with asthma who smoke need higher-than-usual doses of inhaled steroids, GPs have been warned in new guidance.
But experts said smokers should be encouraged to quit and offered add-on therapy before doses of inhaled steroids were increased, to reduce the risk of serious side-effects.
The SIGN/BTS recommendations on pharmacological management of asthma have been updated after evidence emerged that smoking reduced the benefits of inhaled steroids.
The guidance recommends: 'Clinicians should be aware that higher doses of inhaled steroids may be needed in patients who are smokers or ex-smokers.'
But specialists said evidence that inhaled steroids were less effective in previous smokers was sparse.
Professor Martyn Partridge, professor of respiratory medicine at Imperial College, London, and an adviser on the SIGN/BTS guidance, said:
'Smoking specifically interferes with inhaled steroids gaining access to glucocorticoid receptors in the airways – meaning, in effect, that smokers potentially need more treatment to achieve the same effect. This does not appear to be widely known by doctors or patients.'
Professor Neil Thomson, professor of respiratory medicine at the University of Glasgow, has published research showing that non-smokers with mild asthma responded better to doses of 400mcg of inhaled steroid daily than smokers.
The differences in improvement were reduced when the dose of inhaled steroid was increased to 2,000mcg daily.
But Professor Thomson, an adviser on the original 2003 asthma guideline, warned: 'If you are increasing the dose to a high level you might put the patient at risk of long-term side-effects. I would try an add-on therapy such as a ß-agonist first.'
And Dr Dermot Ryan, a GP in Loughborough and member of the General Practice Airways Group, said: 'The main thing is not to increase inhaled steroids until you have made a concerted effort to get the patient to give up smoking.'
The guidance advises GPs to warn patients that smoking reduces effectiveness of therapy. It also warns that children on high steroid doses should be monitored by specialists, and that increasing doses in adults was often ineffective.
Dr Ryan said patients should be told that if asthma was poorly controlled they could stop smoking or take higher-dose inhaled steroids and risk serious side-effects.
How guidance has changed
• Specific written advice about steroid replacement in the event of a severe intercurrent illness should be part of the management plan for children treated with 800mcg per day of BDP or equivalent.
• Any child on this dose should be under the care of a specialist paediatrician.
• In adults, doubling the dose of inhaled steroids at the time of exacerbation is not effective.
• Anti IgE monoclonal antibody: the guideline concludes that as there are no active comparative studies it is not possible to place omalizumab in the stepwise treatment of asthma.
Source: SIGN/BTSDr Dermot Ryan: Don't increase steroids until you've tried to get the patient to quit Dr Dermot Ryan: Don't increase steroids until you've tried to get the patient to quit