Selective oral antimicrobial prophylaxis for the prevention of infection in acute leukaemia-ciprofloxacin versus co-trimoxazole plus colistin. The EORTC-Gnotobiotic Project Group

230 leukaemic patients were entered into a randomised, prospective, multicentre trial of either ciprofloxacin (1 g/day) or co‐trimoxazole (1920 mg/day) plus colistin (800 mg/day) for the prevention of infection during granulocytopenia. Bacteraemia due to resistant gram‐negative rods occurred only in the co‐trimoxazole‐colistin group though both regimens were effective for selective gastrointestinal tract decontamination. However, there were fewer patients without any infective complications (31% vs. 18%: P = 0.02), fewer febrile days [mean (S.D.) 5.9 (1.1) vs. 8.2 (1.4): P = 0.0242], a lower proportion of infective events (0.9 (0.16) vs. 1.2 (0.18): P = 0.005) and fever occurred later (median 19 vs. 14 days: 0.025 less than P less than 0.05) in the co‐trimoxazole‐colistin group. The choice of prophylactic regimen therefore appears to depend upon whether or not protection against gram‐negative infection is required or better systemic prophylaxis overall.