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Monday, April 20, 2015

"Sequential antibiotics" or "Antibiotic Switching" may help avoid antibiotic resistance

Contributed by Dr. Akilesh Ramasamy & Dr. A. J. Tamhankar
Sequential use of antibiotics could have synergistic effect to avoid development of antibiotic resistance or even combat already resistant bacteria. While the use of combination of antibiotics has always been used for their synergistic effect, the use of sequential use of synergistic antibiotics is a new approach by Fuentes-Hernandez et al.(1) The first antibiotic sensitises the organism and the second antibiotic delivers the killing shot. While premature exhilaration on this finding should be limited as this study has found only about 6 sequences which have been found to be effective after trying about 139 different sequences. The study is in it's infancy stage but gives us a new approach to dealing with antibiotic resistance as the technique succeeded in clearing bacteria which had partial resistance to both the antibiotics. 
The results must be viewed with caution as the study has been done in-vitro and it is a known fact that bacteria could behave differently when inside the host. Moreover, the correct sequence and the doses could be important. In that scenario, the use of antibiotics at the exact dose and at specific exact times might be important for the sequential treatment to succeed in humans. The practical implications are numerous as in an already overloaded healthcare setting, there is a high chance that a particular dose might be missed, delayed or given early thus thwarting the entire exercise. So, new formulations or techniques of drug delivery agents might come up which release the particular dose of antibiotic at particular sequence and time. These developments are possible if the sequential antibiotic treatment is found successful in humans. In addition, it also gives hope to the old antibiotics which have been discarded due to development of almost universal resistance to them.


1: Fuentes-Hernandez A, Plucain J, Gori F, Pena-Miller R, Reding C, Jansen G, Schulenburg H, Gudelj I, Beardmore R. Using a sequential regimen to eliminate bacteria at sublethal antibiotic dosages. PLoS Biol. 2015 Apr 8;13(4):e1002104. doi: 10.1371/journal.pbio.1002104. eCollection 2015 Apr. PubMed. PMID: 25853342.