Controlled, comparative study of ciprofloxacin versus ampicillin in treatment of bacterial respiratory tract infections.

The efficacy and safety of ciprofloxacin in bacterial bronchitis were compared with those of ampicillin in a double-blind, prospective clinical trial. Eighty-seven patients received either oral ciprofloxacin (750 mg twice daily) or oral ampicillin (500 mg four times daily). Ciprofloxacin was as effective as ampicillin and produced a 98 percent clinical cure rate. Significantly more pretreatment bacterial isolates were susceptible to ciprofloxacin (p less than 0.05), and ciprofloxacin had a significantly higher rate of sputum sterilization than did ampicillin (p less than 0.05). Ciprofloxacin showed broad in vitro antibacterial activity with particularly low minimal inhibitory concentrations for gram-negative organisms. Ciprofloxacin was well tolerated; there were few adverse effects, and patients had a significantly lower incidence of diarrhea with ciprofloxacin than with ampicillin (p less than 0.05). Ciprofloxacin was an effective and well-tolerated treatment for bacterial bronchitis that had the advantages of broad in vitro antibacterial activity and twice-daily dosing.