There is a clear trade off between the use of macrolides to prevent exacerbations in severe asthma and the likelihood of patients experiencing adverse events such as gastrointestinal symptoms.
Dr Chris Cates, co-ordinating editor of the Cochrane Airways Review Group in the UK, told the TSANZSRS 2019 meeting that a 2015 review of the evidence found prophylactic antibiotics had no significant impact on exacerbation rates in asthma.
However the findings changed when the results of the large Australian AMAZES trial led by Professor Peter Gibson were added to the existing data.
Dr Cates said on a number needed to treat (NNT) basis, seven patients had to be treated with azithromycin to prevent one exacerbation.
However a more recent Cochrane Review on adverse events with macrolide antibiotics highlighted the potential downsides of the drugs for some patients.
The review, comprising 183 studies with a total of 252,886 participants, found that people taking macrolides were up to twice as likely to experience gastrointestinal adverse events as people taking placebo.
Odds ratios ranged from 1.27 for vomiting, 1.61 for nausea, 1.66 for abdominal pain, 1.70 for diarrhoea to 2.16 for other non-specified gastrointestinal disorders.
Dr Cates, a primary care physician, said it was his opinion that prescribing long-term courses of macrolides for chronic respiratory diseases was the job of specialists, not GPs.
“They [specialists] don’t undertake starting people on azithromycin lightly. They screen people for atypical infections, for cardiovascular problems and other things to try and make the treatment as safe as possible and to target the people who are most going to benefit from it.”