Selected Antimicrobial Information – Companion Animal

Nitrofurantoin [Companion]

Restriction Status

Unrestricted

Dose

Species Usage Dose
Cats For urinary tract infections 4.4-5mg/kg PO q8h for 7-14d (extra-label use)
For prophylaxis 4mg/kg PO q24 (extra-label use)
Dogs For urinary tract infections 4.4-5mg/kg PO q8h for 7-14d (extra-label use)
For prophylaxis 4mg/kg PO q24 (extra-label use)

Brand Name(s)

Macrodantin®, Macrobid®

Background

Nitrofurantoin is a bacteriostatic nitrofuran antibiotic. It may also be bactericidal depending on concentration achieved and susceptibility of specific organisms. Its pharmacokinetic/pharmacodynamic relationship is poorly understood. It has excellent activity against Gram-positive and Gram-negative aerobes, but it is not effective against anaerobes, Proteus spp., or Pseudomonas aeruginosa. Nitrofurantoin is rapidly eliminated after absorption, and so therefore only achieves therapeutic concentrations in urine, where it is excreted as active drug.

Acceptable Uses

  • Treatment of urinary tract infections, particularly those documented to be resistant to first-line antimicrobial choices.
  • Prevention of urinary tract infections in patients with documented recurrent urinary tract infections. Use as a preventive can begin after prior treatment with an effective antibiotic at a therapeutic dose and resolution of clinical signs.

Unacceptable Uses

  • Treatment of infections other than urinary tract infections.

Formulations Available within the OSU Pharmacy

  • Nitrofurantoin 50mg capsule
  • Nitrofurantoin 0.2% ointment
  • Macrodantin 25mg capsule

Notes

  • N/A

License

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OSU VMC Antimicrobial Use Guidelines by The Ohio State University College of Veterinary Medicine is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.