a) As a conventional antibiotic (see section 6.2a) for treatment of respiratory infections especially if S aureus, Mycoplasma or Chlamydia are being considered.

 

b) Recently its effects when used long term (250mg/day if <40kg, 500mg/day >40kg for 6 months) have been studied [Equi et al, Lancet 2002;360:978-84 ]. It was beneficial for lung function (FEV₁ increased by median 5.5%) and reduction of oral antibiotic usage. Its mechanism remains unknown but could be antibacterial, anti-inflammatory or both.

 

Very similar to those for rhDNase (section 6.4) and should include those not benefiting from a 3 month trial of rhDNase.

 

Onset of action is slow (at least 2 months) and a minimum 4, preferably 6 month trial is required. If there has been a beneficial response then one could consider reducing the dosing frequency to alternate days or 3 times per week as in the US study.

 

Theoretically liver function abnormalities and reversible tinnitus although only one transient LFT abnormality was observed during the study. Liver function tests should be performed at any time blood is being taken for other reasons and at annual assessment. Use of azithromycin and erythromycin (pro-kinetic) long term should be avoided due to potential additive side effects

 

When AZM is started, stop prophylactic flucloxacillin or augmentin, unless the patient is known to have macrolide-resistant S aureus or H influenzae (which is becoming increasingly common).