Regular daily doses of an inhaled steroid may be no more effective in mild to moderate asthma than only using a preventer inhaler when symptoms worsen, a US study suggests.
Researchers found no difference on a variety of measures between patients who only used an inhaled steroid when using rescue therapy and those who took regular daily doses.
The results question current British Thoracic Society and SIGN asthma guidelines that recommend daily inhaled steroids for patients with stage two asthma or above.
The researchers said their findings ‘could eventually change the way doctors and patients manage asthma', but GPs warned further studies were needed.
The BASALT study randomised 342 patients with mild to moderate asthma who were controlled by low-dose inhaled steroid therapy into three treatment groups.
The groups took either daily low-dose inhaled steroids as directed by their doctor, steroid dosing that was adjusted on the basis of exhaled nitric oxide testing or a symptom-based adjustment, where patients used a steroid inhaler whenever they needed a rescue inhaler.
The researchers reviewed patients every six weeks for nine months and found no significant statistical difference in time to treatment failure – defined as unscheduled care for an exacerbation or measurements that indicated a significant worsening of control – between the three groups.
Failure rates were 22% for the daily regime, 20% for the nitric oxide testing group and 15% for the symptom-based approach group.
There were also no measurable differences in bronchial reactivity, lung function, days missed from school or work and exacerbation of symptoms and attacks between the three groups.
But cumulative doses of inhaled steroid were much significantly lower in patients who took them when symptomatic, with a monthly beclomethasone use of 832 µg in this group compared with 1,610 µg in those taking regular doses.
Study leader Dr William Calhoun, vice chair for research in internal medicine at the University of Texas in the US, added that adjusting doses of inhaled steroids on the basis of symptoms could be a cheaper and easier option.
He said: ‘The current protocol of daily inhaled steroid use is effective, but the flexibility and immediate probable cost savings for asthma medicine that a symptom-based approach may offer will appeal to many patients.'
Dr Kevin Gruffydd-Jones, a GP in Box, Wiltshire, who has been involved in the development of several asthma guidelines, said the study showed that intermittent use of inhaled steroids could be useful for some patients, but that it was a fairly small trial.
He said: ‘There are pointers from this and other studies that, in a selected group of patients, this intermittent approach might help – but in the vast majority of adult patients, regular treatment with inhaled steroids is still more appropriate.
He added that asthma was a fluctuating condition and patients who appear mild at times may have periods when their condition is moderate to severe.
He said: ‘We still need further studies to look at this intermittent regime in very mild patients, particularly those whose condition may be related to hay fever and so on.'
Daily doses of inhaled steroids - 22%
Intermittent dosing when taking rescue medication - 19%