Selection of multiresistant coliforms by long-term treatment of hypercholesterolaemia with neomycin.

Patients with hypercholesterolaemia are often treated with the antimicrobial agent neomycin. Such treatment is potentially dangerous, however, as it may favour the emergence of multiresistant, R-factor-carrying, enteric bacteria among the intestinal flora. In 11 out of 14 patients who had received neomycin for three months to eight years most of the faecal coliforms were resistant to at least four antimicrobial drugs and capable of transferring this resistance to others. In contrast, only one out of nine patients who were treated with other lipid-lowering drugs had resistant bacteria in their faeces. Neomycin may cause multiresistant strains to emerge because, like tetracycline, it forms high concentrations in the gut. Long-term treatment of non-infectious conditions like hypercholesterolaemia with neomycin is potentially dangerous not only to the patient but also to the community because of the creation of a reservoir of multiresistant organisms.