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ANTIBIOTICS AND pH

First broadcast on www.provet.co.uk


This information is provided by Provet for educational purposes only.

You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Some antibiotics are highly influenced by pH 

The pH of the local environment can influence how effective an antibiotic is, and pH is extremely important for the following antibiotics :

  • Erythromycin - optimal range 7.5-8
  • Neomycin - optimal range 5.5-6
  • Nitrofurantoin - optimal pH 6
  • Streptomycin - optimal range 7.5-8
  • Chlortetracycline - optimal pH 6

For the treatment of urinary tract infections - particularly in association with urolithiasis - it is also worthwhile considering the following optimal ranges of pH for antibiotic efficacy :

  • Ampicillin - optimal range 5.5-6.5
  • Chloramphenicol - optimal range 7.5-8
  • Kanamycin - optimal range 7.5 - 8
  • Methanamine maleate - optimal range 5.5-6
  • Penicillin G - optimal range 6-6.5
  • Polymyxin - optimal range 8
  • Oxytetracycline - optimal range 5.5-6.5

Sulphonamides are not affected by pH, but their solubility decreases in acidic urine (pH 5.5)

 

Updated October 2013