- Broad-spectrum antibiotic
The term broad-spectrum antibiotic refers to an
antibiotic with activity against a wide range of disease-causingbacteria . It is also means that it acts against bothGram-positive andGram-negative bacteria. This is in contrast to anarrow-spectrum antibiotic which is effective against only specific families ofbacteria . A good example of a commonly used broad-spectrum antibiotic islevofloxacin .Fact|date=June 2008Uses
Broad-spectrum antibiotics are properly used in the following medical situations:
* Empirically prior to identifying the causative bacteria when there is a wide differential and potentially serious illness would result in delay of treatment. This occurs, for example, in
meningitis , where the patient can become so ill that he/she could die within hours if broad-spectrum antibiotics are not initiated.*For drug resistant bacteria that do not respond to other, more
narrow-spectrum antibiotic s.* In super-infections where there are multiple types of bacteria causing illness, thus warranting either a broad-spectrum antibiotic or combination antibiotic therapy.
There has been a common usage of broad-spectrum agents in treatment of community acquired infections without attempting to culture or otherwise identify the causative bacteria. Over the years, this practice has contributed to the emergence of more drug resistant strains of bacteria, necessitating the development of newer broad-spectrum antibiotics.
Ideally, the spectrum should be "narrowed down" by identifying the causative agent of an infection, and then replacing the broad-spectrum antibiotic with an appropriate "narrower-spectrum"
antibiotic . This is believed to limit the development ofantibiotic resistance , although evidence for this practice is unclear.Examples
In
medicine :
*amoxicillin
*levofloxacin , gatifloxacin, moxifloxacinIn
veterinary medicine ,Co-amoxiclav (e.g.Synulox , fromPfizer ) (in small animals);penicillin &streptomycin (e.g. Streptacare from Animalcare Ltd) andoxytetracycline (in farm animals);penicillin and potentiated sulphonamides (e.g. Equitrim,Boehringer ) (in horses).ee also
*
Empiric therapy
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