The interactions of metal ions with quinolone antibacterial agents

The quinolones are a group of synthetic antibacterial agents structurally related to nalidixic acid. The absorption of quinolone drugs is lowered when they are consumed simultaneously with magnesium or aluminium antacids. Many other ions found in pharmaceuticals cause similar effect. The proposed reason for such behaviour is the chelate bonding of the quinolone to the metal. In the review article, selected crystal structures of quinolone–metal compounds are presented and discussed. The results of different physico-chemical methods (thermal analysis, potentiometric measurements, IR, UV–vis, NMR spectroscopy) as well as some results of bioactivity tests are also included.