MIMS recently reported that chloramphenicol eye drops are now contraindicated in children less than 2 years old.
The change followed a ruling by the European Medicines Agency that all preparations containing boric acid or borates at a level that would result in exposure to more than 1mg daily of boron or 5.7mg daily of boric acid should not be used in children under 2 years, because of the future risk of impaired fertility.
However, the Royal College of Ophthalmologists says it believes the benefits of chloramphenicol eyedrops in paediatric ophthalmic practice 'for appropriate indications and with courses of appropriate duration outweigh the possible risks posed by boron ingestion.'
In a safety alert, the college says chloramphenicol eye preparations have been widely used in children of all ages for many years with no documented adverse effects on fertility, and it is not aware of any new scientific data from human studies to support the change to the product licence.
There are circumstances where chloramphenicol eye drops are required in preference to eye ointment and no suitable alternative product exists, the college points out. Other antibiotic eye drops (eg, gentamicin) may also contain boron, and commonly available non-boron-containing products suitable for young children, such as fusidic acid and azithromycin, have a much narrower spectrum of activity than chloramphenicol, and may not be a suitable replacement.
The college advises that quinolone or broad-spectrum cephalosporin drops (some of which contain no boron) be reserved for severe eye infections such as keratitis and endophthalmitis to maintain their effectiveness and not be used routinely for simple bacterial conjunctivitis.
Most manufacturers do not list boron content for their products but those that do give a range of 1.1–2.9mg/ml. Given that the maximum volume that can be accommodated in the conjunctival sac is between 10–20 microlitres, the college calculates that a typical regime of one drop to either eye four times daily would result in a daily exposure well below 1mg/day, even if 100% absorption is assumed.
The college says it is seeking to work with the MHRA and the DHSC medicine supply team to ensure the advice given by all national bodies and suppliers on this issue 'is proportionate and supports clinical requirements'.
The Specialist Pharmacy Service (SPS) says chloramphenicol eye ointment preparations do not contain boric acid or borates and so can be prescribed for children less than 2 years old. However, pharmacy-only preparations of chloramphenicol are not licensed for sale or supply to children under 2 years over the counter, although the SPS highlights that they are not contraindicated.