Combination antibiotic

A combination antibiotic is one in which two ingredients are added together for additional therapeutic effect.^[1] One or both ingredients may be antibiotics.^[1]

Antibiotic combinations are increasingly important because of antimicrobial resistance.^[2] This means that individual antibiotics that used to be effective are no longer effective,^[1] and because of the absence of new classes of antibiotic, they allow old antibiotics to be continue to be used.^[2] In particular, they may be required to treat multiresistant organisms,^[1][2] such as carbapenem-resistant Enterobacteriaceae.^[3] Some combinations are more likely to result in successful treatment of an infection.^[1]

Uses

Antibiotics are used in combination for a number of reasons:

• to treat multiresistant organisms,^[1][2] such as carbapenem-resistant Enterobacteriaceae.^[3]
• because a person may be infected with more than one microbe simultaneously,^[3] for example infections of the abdominal cavity after bowel perforation.
• because antibiotics used together may act synergistically to increase the efficacy of both,^[3]
• because antibiotics used together may have a broader spectrum than each antibiotic used individually.^[3]

Examples

Examples of combinations include:^{[citation needed]}

• 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
• Piperacillin/Tazobactam

Research

Research into combination antibiotics is ongoing.^[1]