Fusidic acid is available in gel form and, therefore, the typical dose is twice a day to be continued for 48 hours after resolution. This is an option for optometrists only and is considered especially appropriate if a Staphylococcal infection is identified. (5) However, like chloramphenicol, it is not effective against some species or strains of bacteria.
In the other articles in this series, the subject of preservatives was discussed, why they were in some products and their potential disadvantages. In eye drops to be used for a short time, it may be thought the disadvantages of preservatives would not be so significant. However, some patients are sensitive to them, which may cause enough discomfort to put the patient off using them, or the eye’s hyperaemic reaction to them may hide a continuing infection.
The relatively ‘new kid on the block’, a preservative-free form of azithromycin, is Azyter (Figure 2), which is specifically licensed for bacterial conjunctivitis. Other than not using it due to an existing hypersensitivity to azithromycin, there are few contra-indications, with no age restrictions. It can be used in pregnancy and while breastfeeding. Dosing is twice per day for three days. Like other bacteriostatic antibiotics already discussed, it is not effective against every species or strain of bacteria, so in cases of suspected Pseudomonas aeruginosa, more likely in contact lens wearers, it may not be a preferred choice.