Type of Medication: Antibiotic

Indications: Treatment of community acquired upper and lower respiratory tract infections. Used in low dose in CF and non CF bronchiectasis for anti-inflammatory property. Haemophilus, Mycoplasma, MSSA, M. abscessus, M. avium infections.

Side Effects: Examples of side effects include nausea, vomiting, abdo pain, diarrhoea, urticaria, rashes, reversible hearing loss, cholestatic jaundice. Cardiac effects rare i.e chest pain, arrythmias. Photosensitivity, mild neutropenia, increased ALT and AST.

Potential for hepato- and ototoxicity but usually very well tolerated

Can cause tooth and tongue discolouration.

Avoid long term concurrent use with erythromycin

Baseline ECG should be undertaken to identify QTc prolongation. Use with caution if QTc prolonged.

Avoid single agent treatment with a macrolide in patients who have grown M. abscessus or M. avium due to risk of emergent resistance with unopposed macrolides.

Check liver function 1 month after commencing continuous azithromycin therapy and avoid in severe liver disease.

Caution in renal impairment: increase in systemic exposure to azithromycin.

Route of administration: Adult (Oral)

Dose: (Oral Antibiotic): 10 mg/kg od, max 500 mg.

Dose:  (Anti-inflammatory dose):  250 to 500 mg three times a week. (<15kg: 10mg/kg od three times a week. 15-40 kg: 250mg od three times a week. >40kg: 500mg od three times a week. Example of dosing regime –  Monday, Wednesday and Friday.

Dose: (Oral treatment of Mycobacterium abscessus infections):  10 mg/kg od, max 500 mg (250–500 mg once daily).

Administration: Give on an empty stomach. In chronic treatment repeat 3 day course every 14 days. Available as 200 mg/5ml suspension or 250 mg capsules or 500 mg tablets

Route of administration: Paediatric oral

Dose: > 6 months 10 mg/kg/day. 15-25 kg 200 mg od. 26-35 kg 300 mg od, 36-45 kg 400 mg od.

Limited data on dosing in NTM. NTM treatment –  Child 6 months–17 years. 10 mg/kg once daily (maximum per dose 500 mg) (oral). Child 6 months–17 years (body weight 15–25 kg): 200 mg once daily (oral). Child 6 months–17 years (body weight 26–35 kg): 300 mg once daily (oral). Child 6 months–17 years (body weight 36–45 kg): 400 mg once daily (oral). Child 6 months–17 years (body weight 46 kg and above): 500 mg once daily (oral).

Examples of some Drug Interactions

Interacting drug: Antacids– reduce absorption of azithromycin

Interacting drug: Cyclosporin -increase cyclosporin level

Interacting drug: Rifabutin – increased plasma concentrations with macrolides

Interacting drug: Tacrolimus – increased plasma levels with macrolides

Interacting drug: Warfarin – may increase INR