Synergies of different combinations of antibiotics
The use of combinations of antibiotics is useful because there may be synergies. [ 47 ] This is particularly beneficial for use in revision surgery.
The synergies can refer to both the release behaviour and the antimicrobial efficacy.
For example, it can be shown that combining gentamicin and clindamycin greatly increases the release of each of the antibiotics. [ 31, 44, 50 ; see figure]
The combination of gentamicin and vancomycin shows a significant antimicrobial synergy as shown by the stronger killing effect of the combination on Staphylococci. The hypothesis behind that observation is that gentamicin can penetrate the cells better when it is combined with vancomycin and this leads to a large increase in the killing rate. [ 45, 49 ]
However, not all combinations have a positive effect. There may be antagonistic effects when combining two antibiotics with the same mechanism of action, for example. [ 1, 33 ]