Antibiotics for respiratory conditions

Viral exacerbations are not generally susceptible to conventional antibiotics; however, this is often superseded by bacterial infection, at which stage the sputum becomes purulent and an antibiotic should be prescribed.

  • Antibiotics are usually given over a short course, 5-7 days for exacerbations of COPD for example. In some diseases, research has shown it to be more beneficial to have longer courses, 14 days for example, in bronchiectasis.
  • Prior to starting an antibiotic for an infection, ideally the choice of antibiotic should be tailored to the organism causing the infection. This can only be done by submitting a sputum specimen to a laboratory for bacterial and antibiotic sensitivity to be identified.
  • Antibiotics may need to be started before results become available and lack of results should not prevent antibiotics being given.
  • Often a broad spectrum antibiotic is given to cover the most likely bacteria. If patients fail to improve after several days, antibiotic choice may be changed on basis of laboratory results.

When choosing an antibiotic, minimising the risk of resistance is vital.

  • Using the shortest course that is likely to be effective minimises the risk of resistance and side effects.
  • Five days is ideal for most patients. If more severely unwell seven days and for bronchiectasis patients fourteen days.
  • Previous exacerbations, exposure to antibiotics and hospital admissions need to be taken into account when deciding if and which antibiotic is suitable.
  • Amoxicillin, Doxycycline, Clarithromycin are the usual first line choices.
  • For patients who are more unwell or if there is a greater risk of resistance then Co-amoxiclav, Levofloxacin are used.
  • For bronchiectasis, the first choice is the same but alternative management is then guided by sputum culture and sensitivity with consideration given to long term antibiotics and nebulised antibiotics.