Safety of the new fluoroquinolones compared with ciprofloxacin.

Significant safety issues that have arisen with fluoroquinolones include phototoxicity, cardiotoxicity, tendinitis, CNS effects and drug interactions. Ciprofloxacin is well tolerated; the incidence of adverse events is low and serious adverse events are rare. Levofloxacin has a reduced CNS adverse event rate compared with ofloxacin. Sparfloxacin has significant phototoxicity and potential cardiac toxicity. Grepafloxacin has significantly increased adverse event rates, particularly gastrointestinal intolerance. Taste perversion and nausea are common. Trovafloxacin has an increased potential for CNS adverse reactions, notably dizziness. Post-marketing surveillance data indicate the possibility of serious hepatic reactions and pancreatitis. Interactions between fluoroquinolones and drugs metabolised by the hepatic cytochrome P450 system affect the clearance of theophylline and caffeine. Quinolone absorption is significantly reduced by co-administration of antacids. Hospitalised patients are likely to be receiving multiple-drug therapy, but drug interactions are avoidable. The interactions of specific fluoroquinolones should be checked prior to prescription.