Back to Antimicrobial Agents

Brand

Orbax

Availability

Tablets: 5.7 mg, 22.7 mg, & 68 mg

Pharmacology

Orbifloxacin, a 4-fluoroquinolone, is a concentration dependent bactericidal drug. Its mechanism of action is to inhibit bacterial DNA gyrase, and prevent DNA supercoiling and synthesis. It has activity against Gram-negative and Gram-positive bacilli and cocci such as: Klebsiella spp., enterobacter, shigella, Staphylococcus aureus, and E. coli.
Strains of pseudomonas and enterococcus are resistant to orbifloxacin.

It is 95% absorbed, though eliminated by the kidneys 50% unchanged.
This higher absorption rate, with urine levels remaining above minimum inhibitory concentration for susceptible organisms, may mean lower dosages in less of a frequency need be given.

The safety of this drug for use in pregnant and nursing animals has not been determined.

Indications

Useful in urinary tract infections, and soft tissue injury.

Drug Interactions or Contraindications

Antacids containing Magnesium, Calcium, and Aluminum will prevent absorption.

Theophylline blood levels may be increased when used with orbifloxacin.

Probenecid blocks tubular secretion of orbifloxacin and may cause an increase in its blood level and half life.

Synergism can occur when aminoglycosides, cephalosporins, and extended-spectrum penicillins are used with fluorinated quinolones such as orbifloxacin.

Not recommended to be given to pregnant or very young rats due to the risk of causing cartilage abnormalities.

Adverse Reactions

CNS: restlessness, may lower seizure threshold (increasing likelihood of seizure activity)

GI:  decreased appetite, diarrhea

GU:  crystalluria

Skin:  Can cause tissue damage when given IM or SQ.

Other:  itching

Dosage Recommendations

The dosages listed below are what some limited vets are using. There is no written documentation regarding dosages for rats. *Dosing is empiric.*

Dosing ranges that have been reported are 1 mg/lb to 5 mg/lb , PO ,q24hrs (5 mg/lb for MSU Veterinary Internal Medicine)

Dose reported being the most effective in rats is 5 mg/lb, this is also empiric.

*NOTE*Toxicity less likely in once daily dosing therapy for aminoglycosides and the fluorinated quinolones.

Considerations

• Store tablets in tight moist free container.
• Be sure to keep animals well hydrated in order to prevent crystalluria (formation of crystals in urine).
• Reconstituted suspension from tablets should be kept refrigerated and has a 14 day expiration time.
• Orbifloxacin can be used simultaneously with doxycycline in the treatment of Mycoplasma.

  Also, in treating suspected polymicrobial infections, where a broader coverage may be needed, synergistic or combination drugs may be used. The following drugs may be seen used simultaneously with ciprofloxacin: aminoglycosides (e.g., amikacin or gentamicin), or aminopenicillins (e.g., amoxicillin or ampicillin), or third generation cephalosporins, or clindamycin, or metronidazole.  ¹

• Please note that it is imperative to discuss the changing or adding of any medications during your rat’s treatment with your veterinarian to prevent future resistance of microbes to the drugs prescribed.

Posted on June 23, 2003, 14:17, Last updated on December 2, 2008, 20:34 | Antimicrobial Agents