Purpose: To assess the relevance of antibiotic combinations according to available recommendations.
Methods: Prospective monocentric study of 12-month duration in the department of internal medicine of a teaching hospital. All antibiotic combinations were assessed taking into account the infection type, the involved bacteria, the antibiotic nature, dosage and duration of treatment. A scientific committee classified each combination antibiotic therapy as: (1) in agreement with existing recommendations; (2) adapted to the antibiogram in the absence of available recommendations; (3) irrelevant but with no adverse clinical outcome for the patient; (4) irrelevant with potential adverse clinical outcome for the patient.
Results: Among 87 antibiotic combinations prescribed, 67 (77%) agreed with available recommendations. The percentages of irrelevant combinations with and without potential adverse clinical outcome for the patient were 7% (six cases) and 16% (14 cases), respectively. Reasons for non-conformity included: (1) prescription of combination therapy while monotherapy could have been sufficient or antibiotic therapy was unjustified (14 cases); (2) prescribed antibiotics not adapted to antibiogram (three cases); (3) prescribed antibiotics not effective on the most likely bacteria when treatment of infection was empirical (three cases). The rate of prescription appropriateness was 97% when the mobile microbiology team had interfered with the decision, versus 53% (p<0.001) when it had not.
Conclusion: Seventy-seven percent of antibiotic combinations were appropriate and agreed with available recommendations. The advice of a microbiology team markedly improves this rate.