A combination antibiotic is one in which two ingredients are added together for additional therapeutic effect.
One or both ingredients may be antibiotics.
Antibiotic combinations are increasingly important because of
antimicrobial resistance
Antimicrobial resistance (AMR or AR) occurs when microbes evolve mechanisms that protect them from antimicrobials, which are drugs used to treat infections. This resistance affects all classes of microbes, including bacteria (antibiotic resista ...
.
This means that individual antibiotics that used to be effective are no longer effective,
and because of the absence of new classes of antibiotic, they allow old antibiotics to be continue to be used.
In particular, they may be required to treat
multiresistant organisms,
such as
carbapenem-resistant Enterobacteriaceae.
Some combinations are more likely to result in successful treatment of an infection.
Uses
Antibiotics are used in combination for a number of reasons:
* to treat
multiresistant organisms,
such as
carbapenem-resistant Enterobacteriaceae.
* because a person may be infected with more than one microbe simultaneously,
for example infections of the
abdominal cavity
The abdominal cavity is a large body cavity in humans and many other animals that contain Organ (anatomy), organs. It is a part of the abdominopelvic cavity. It is located below the thoracic cavity, and above the pelvic cavity. Its dome-shaped roo ...
after
bowel perforation.
* because antibiotics used together may act
synergistically
Synergy is an interaction or cooperation giving rise to a whole that is greater than the simple sum of its parts (i.e., a non-linear addition of force, energy, or effect). The term ''synergy'' comes from the Attic Greek word συνεργία ' f ...
to increase the efficacy of both,
* because antibiotics used together may have a broader spectrum than each antibiotic used individually.
Examples
Examples of combinations include:
*
Amoxicillin/clavulanic acid, which includes the
beta lactam amoxicillin with the
suicide inhibitor clavulanic acid, which helps the amoxicillin overcome the action of
beta lactamase
*
Trimethoprim/sulfamethoxazole
Trimethoprim/sulfamethoxazole, sold under the trade names Bactrim, Cotrim (a short form of the British Approved Name, Co-trimoxazole) and Septra, among others, is a fixed-dose combination antibiotic medication used to treat a variety of bacte ...
*
Piperacillin/Tazobactam
Research
Research into combination antibiotics is ongoing.
References
{{reflist
Antibiotics
*