LACK OF EVIDENCE FOR SYSTEMIC TOXICITY FOLLOWING TOPICAL CHLORAMPHENICOL USE

There has been considerable controversy regarding the safety of topica l chloramphenicol in ophthalmic practice. The evidence for associated haematopoietic toxicity in idiosyncratic and dose-dependent forms was reviewed. The 7 cases of idiosyncratic haematopoietic reactions associ ated with topical chloramphenicol reported in the literature are refut able evidence for the existence of such a response. In Scotland, despi te extensive prescription of topical chloramphenicol, the incidence of acquired aplastic anaemia was found to be low, as were associated rep orts of blood dyscrasias throughout the UK. The epidemiology of acquir ed aplastic anaemia failed to make an association with topical chloram phenicol use. High-performance liquid chromatography (minimum detectio n limit 1 mg/l) was used to investigate whether serum accumulation of chloramphenicol occurred after topical therapy in 40 patients. The mea n dose of chloramphenicol eye drops used after 1 week of treatment was 8.0 mg, and after 2 weeks, 15.3 mg. As expected, chloramphenicol fail ed to accumulate to detectable levels. This supported the view that to pical chloramphenicol was not a risk factor for inducing dose-related bone marrow toxicity. Calls for the abolition of treatment with topica l chloramphenicol based on current data are not supported.