Clinical experiences with fusidic acid in cystic fibrosis patients.

A survey of Staphylococcus aureus lung infection in 243 patients with cystic fibrosis (CF) was conducted between 1986 and 1988. A total of 217 patients (89%) received 1605 courses of anti-staphylococcal therapy given during this period. The majority of courses comprised combined therapy with two anti-staphylococcal drugs. The combination of dicloxacillin and fusidic acid was employed most frequently. Some patients were given other anti-staphylococcal regimens, because of penicillin allergy (14 cases) or dyspeptic side effects with fusidic acid (21 patients). A small but significant increase in precipitins against S. aureus was observed during the study period. Bacterial resistance to the anti-staphylococcal drugs used remained at a low level (strains resistant to methicillin less than 0.1%, strains resistant to fusidic acid 1.2%). When the isolates were compared with 56,140 strains of S. aureus isolated from non-CF patients hospitalized in Denmark over the same period, no differences in phagetypes or in antibiotic resistance were seen, indicating that selection of strains and cross infection do not seem to be a major problem in CF patients.