The oral antibiotic combination of amoxicillin with clavulanate potassium, also marketed under the brand name Augmentin, broadens the spectrum of amoxicillin to include bacteria that have enzymes associated with resistance to antibiotics. These enzymes inactivate amoxicillin.
Clavulanate potassium has little antibacterial activity of its own but potently inhibits bacterial enzymes called beta-lactamases. Amoxicillin with clavulanate potassium provides a treatment option for infections due to resistant organisms.
Identification
According to its package insert, Augmentin consists of an oral antibiotic amoxicillin, a broad-spectrum penicillin, combined with the beta-lactamase inhibitor clavulanate potassium. It comes in powder or tablet forms. The 250mg, 500mg, 875mg and 2,000mg extended-release tablets each contain 125mg of clavulanate potassium.
Significance
Amoxicillin has an antibacterial spectrum identical to ampicillin, but it has better absorption from the intestine, which results in higher blood and urine concentrations. According to The Washington Manual of Medical Therapeutics, amoxicillin treats bacterial infections such as uncomplicated sinusitis, pharyngitis, otitis media, and urinary tract infections when the organism does not produce beta-lactamase.
For beta-lactamase producing organisms, an antibiotic combination neutralizes the enzyme. Amoxicillin-clavulanate potassium was developed for this purpose.
Function
Amoxicillin, or Amoxil, is classified as a beta-lactam antibiotic because the molecule contains a ring in its chemical structure. Other beta-lactam antibiotics include penicillins, cephalosporins and several other antibiotics.
Clavulanate potassium, a beta-lactam structurally related to penicillin, serves as a "suicide inhibitor;" it sacrifices itself by binding to beta-lactamases produced by bacteria. Clavulanate potassium prevents the enzymes from breaking the beta-lactam ring in amoxicillin---the way beta-lactamases inactivate beta-lactam antibiotics.
Uses
Amoxicillin-clavulanate potassium gives physicians an antibiotic to treat patients who do not improve by the third day of amoxicillin therapy, have documented infections because of organisms resistant to amoxicillin or have complicated sinusitis, otitis media and skin and skin structure infections.
The U.S. Food and Drug Administration defines complicated skin and skin-structure infections as those that involve the deep soft tissue, require significant surgical intervention, such as infected ulcers, burns and major abscesses, and/or significant underlying disease that complicate a patient's response to treatment. A complicated infection with a resistant organism is harder to treat than an uncomplicated infection with a sensitive organism.
According to The Washington Manual of Medical Therapeutics, human bites, especially injuries because of a clenched fist can easily become infected. Of animal bites, dogs are responsible for 80 percent, but only 20 percent become infected. For prophylaxis of uninfected human or dog bites, amoxicillin-clavulanate, the preferred antibiotic, is given for three to five days.
Warnings
Augmentin's package insert warns that "serious and occasionally fatal hypersensitivity, anaphlactic reactions have been reported in patients on penicillin therapy."
In addition, "clostridium difficle associated diarrhea has been reported with nearly all antibacterial agents, including Augmentin."
References
- The Washington Manual of Medical Therapeutics; Gopa Green, M.D.; 2004
- Augmentin Package Insert; PDR; 2009
- FDA: Uncomplicated and Complicated Skin and Skin Structure Infections
- Harrison's Principles of Internal Medicine; Dennis Kasper, M.D., et al; 2005
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