Azithromycin Eye Drops (AzaSite) versus ...

Based on "Antibiotic and Chemotherapy"
written by Roger G. Finch

Azithromycin Ophthalmic vs Tobramycin Ophthalmic

Bacterial Conjunctivitis in Children and Adults

Both antibiotic eye drops are very effective in the treatment of purulent bacterial conjunctivitis4. Azithromycin 1.5% eye drops may provide a quicker resolution of conjunctivitis signs than tobramycin.

Study Results4 Azithromycin (Azyter®) Tobramycin
Regimen Azithromycin 1.5% eye drops twice-daily for 3 days Tobramycin 0.3% eye drops 1 drop every 2 hours for 2 days, then 4 times daily for 5 days
Clinical cure - number (%) of patients with bacteriological resolution in the worse eye (on day 9) 215 (87.8%) 202 (89.4)
Earlier clinical cure rate (on day 3) 29.8% 18.6%
Bacteriological resolution in the worse eye on day 9 (number (%) of patients) 219 (92.8%) 211 (94.6%)
Bacteriological resolution in the worse eye on day 3 (number (%) of patients) 202 (85.2%) 181 (83.8%)
Eye drops rated as comfortable on day 9 by 95% of patients by 95% of patients

Epithelial wound healing after corneal surgery

Azithromycin and tobramycin eye drops provide similar effects in the prevention of infection and epithelial healing, and have similar ocular tolerance after penetrating keratoplasty5.

Azithromycin (AzaSite) vs Tobramycin/Dexamethasone (TobraDex)

Blepharitis, Blepharoconjunctivitis

Tobramycin/Dexamethasone provides faster inflammation relief than azithromycin for moderate to severe blepharitis/blepharoconjunctivitis 6.

Azithromycin (AzaSite) vs Moxifloxacin (Vigamox) Ophthalmic Drops

Tolerability and Patient's preference

Most patients prefer moxifloxacin drops to azithromycin drops1. Moxifloxacin drops are more comfortable and acceptable with less blurring than azithromycin. Moxifloxacin was significantly more tolerable than azithromycin in healthy adult and pediatric eyes.

Study Results1 Azithromycin drops Moxifloxacin drops
Ocular side effects (redness, irritation, stinging, burning, dryness, itching and chemosis) 18 patients (17.3%) 1 patient (1%)
Tolerability and Patient's preference   High


Resistance to azithromycin is more common than resistance to moxifloxacin in bacteria causing bacterial conjunctivitis2.


Azithromycin provides higher concentrations in human conjunctiva than moxifloxacin3. Moxifloxacin achieved lower conjunctival tissue levels, but higher aqueous humor levels. Azithromycin also has an extended half-life in conjunctiva.

Study Results3 Azithromycin drops Moxifloxacin drops
Half-life in conjunctiva 65.7 hours 28.6 hours
Peak aqueous humor concentration 0.77 μg/mL 0.053 μg/mL
Time while the concentration of antibiotic solution was maintained well above the minimum inhibitory concentration required for inhibition of growth of 90% of tested bacterial isolates for at least 7 days 24 hours after the last dose

Further reading

  • 1. Granet D, Lichtenstein SJ, Onofrey B, Katz JA. An assessment of the tolerability of moxifloxacin 0.5% compared to azithromycin 1.0% in DuraSite. Clin Ophthalmol. 2007 Dec;1(4):519-25.
  • 2. Ohnsman C, Ritterband D, O'Brien T, Girgis D, Kabat A. Comparison of azithromycin and moxifloxacin against bacterial isolates causing conjunctivitis. Curr Med Res Opin. 2007 Sep;23(9):2241-9.
  • 3. Stewart WC, Crean CS, Zink RC, Brubaker K, Haque RM, Hwang DG. Pharmacokinetics of azithromycin and moxifloxacin in human conjunctiva and aqueous humor during and after the approved dosing regimens. Am J Ophthalmol. 2010 Nov;150(5):744-751 PubMed
  • 4. Cochereau I, Meddeb-Ouertani A, Khairallah M, Amraoui A, Zaghloul K, Pop M, Delval L, Pouliquen P, Tandon R, Garg P, Goldschmidt P, Bourcier T. 3-day treatment with azithromycin 1.5% eye drops versus 7-day treatment with tobramycin 0.3% for purulent bacterial conjunctivitis: multicentre, randomised and controlled trial in adults and children. Br J Ophthalmol. 2007 Apr;91(4):465-9. PubMed
  • 5. Blavin J, Sauer A, Saleh M, Gaucher D, Speeg-Schatz C, Bourcier T. A comparison of azithromycin and tobramycin eye drops on epithelial wound healing and tolerance after penetrating keratoplasty. J Ocul Pharmacol Ther. 2012 Aug;28(4):428-32.
  • 6. Torkildsen GL, Cockrum P, Meier E, Hammonds WM, Silverstein B, Silverstein S. Evaluation of clinical efficacy and safety of tobramycin/dexamethasone ophthalmic suspension 0.3%/0.05% compared to azithromycin ophthalmic solution 1% in the treatment of moderate to severe acute blepharitis/blepharoconjunctivitis. Curr Med Res Opin. 2011 Jan;27(1):171-8.

Published: January 10, 2014
Last reviewed: February 09, 2017


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