The case reports presented so far, concerning a possible causative relationship between the ophthalmological use of chloramphenicol (O-CAP) and blood dyscrasias, are few in number, not always fully documented and therefore not always convincing. The overall use of this drug in a restricted area in the Netherlands was assessed. On a yearly basis 1:29 people used O-CAP. In a four-year period in the same area, 12 patients with aplastic anemia and 190 patients with other cytopenic dyscrasias were found. After exclusion of all cases with other possible causes of the dyscrasia, e.g. cancer and related therapy, other drugs than O-CAP and infectious diseases, 59 cases remained in which a definite cause could not be established. We traced back the use of O-CAP in the relevant period. No dyscrasias were found that unequivocally were caused by O-CAP. The rate of O-CAP use in the dyscrasia-group was approximately equal to that in the population as a whole. Hence we concluded that it is highly improbable that O-CAP played a part in the etiology of blood dyscrasias in the region. Statistical evaluation of material derived from a much larger region may, however, lead to a more differentiated conclusion.
