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Brands

Marbocyl
Zeniquin

Availability

Tablets: 25 mg, 50 mg, 100 mg, & 1200 mg; Zeniquin
Tablets: 5 mg, 20 mg, 80 mg; Marbocyl

Tablets can be made into suspension.

Injectable: 200 mg powder for reconstitution gives 10mg/ml when reconstituted; Marbocyl (not as yet approved for use in USA)

Pharmacology

Marbofloxacin, a second-generation¹ fluoroquinolone, is a broad-spectrum, concentration dependent bactericidal antibiotic with significant post-antibiotic effect (meaning it lends itself to once-daily application of the total daily dose or pulse-dosing regimens where deemed appropriate). While its mechanism of action is not completely understood it is believed to act by inhibiting bacterial DNA-gyrase, preventing DNA supercoiling and synthesis.

It has activity against some Gram-positive aerobes such as staphylococci, and a wide range of Gram-negative bacilli and cocci, which include klebsiella spp., pasteurella spp., pseudomonas spp., salmonella, and other organisms such as mycoplasma, and chlamydia.

Because the fluoroquinolones have shown variable activity against most Streptococci, as well as weak activity against many anaerobic bacteria, they are not generally recommended for use in treating these types of infections.

When taken orally marbofloxacin is both rapidly and well absorbed. It has not been determined whether the absorption of marbofloxacin is affected when given with food.

Marbofloxacin, like other fluoroquinolones, is a highly lipophilic drug attaining high concentrations within cells in many tissues. It crosses the placenta, is found in breast milk, and can also be found in small concentrations in the cerebral spinal fluid.
Marbofloxacin is eliminated unchanged in the urine, and bile/feces, with only a small percentage being metabolized in the liver.

It is well known that the quinolone class of drugs has been shown to produce erosions of cartilage in weight bearing joints and other signs of arthropathy in immature animals of various species.

It is also important to note that the use of fluoroquinolones has not been recommended for initial treatment in pregnant and nursing does, or rats under 4 months due to the risks of cartilage abnormalities (Egerbacher et al., 2000), however, in cases where other antibiotics are not helping, or if the infection is deemed severe, the benefit of using fluoroquinolones (alone or in combination with other compatible antimicrobials) may in fact outweigh the risks.

The MSDS reported by Pfizer, for marbofloxacin, reveals no evidence of carcinogenic or teratogenic effects in rats.

Indications

Useful in: respiratory infections, urinary tract infections, soft tissue infection and soft tissue injury.

Drug Interactions or Contraindications

Concurrent administration of a quinolone, including marbofloxacin, with cation-containing GI products such as magnesium/aluminum antacids or sucralfate, or GI products containing calcium, iron, or zinc may reduce its absorption. It is suggested to separate dosing from any of these products by 2 hours.

Theophylline blood levels may be increased when used with marbofloxacin.

Probenecid blocks tubular secretion of marbofloxacin 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 marbofloxacin.

Adverse Reactions

CNS: restlessness, seizures

GI:  decreased appetite, diarrhea

GU:  crystalluria

Other:  itching

Dosage Recommendations

2 mg/kg to 5 mg/kg, PO, SQ, IM q24hr  ³² anywhere from 5 to 30 days

or

4 mg/kg, PO, SQ, q24hrs. May give injectable orally.  ³⁴

For appropriate dosing in pulse antibiotic therapy for chronic illness, discuss with veterinarian

Note: see warning for young, pregnant or nursing rats in Pharmacology section above.

Considerations

• Unlike enrofloxacin, marbofloxacin when given by injection does not appear to cause skin ulceration at the injection site.
• Be sure to keep animals well hydrated to prevent crystalluria (formation of crystals in urine).
• Reconstituted suspension from tablets should be kept refrigerated and has a 14 day expiration time.
• When 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 marbofloxacin: aminoglycosides (e.g., amikacin or gentamicin), or aminopenicillins (e.g., amoxicillin or ampicillin), or third generation cephalosporins, or clindamycin, or doxycycline (for mycoplasma), 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.

Reference

• Pallo-Zimmerman, L., Byron, J., & Graves, T. (July 2010). Fluoroquinolones: Then and Now. Vetlearn.com. Retrieved April 25, 2011, from www.vetlearn.com/Portals/0/PV0710_zimmerman_CE.pdf
• Committee for Veterinary Medicinal Products. (October 1999). Marbofloxacin: Summary Report 2. European Medicines Agency. Retrieved April 25, 2011, from www.ema.europa.eu/docs/en_GB/document_library/Maximum_Residue_Limits_-_Report/2009/11/WC500014865.pdf
• Egerbacher, M., Seiberl, G., Wolfesberger, B., & Walter, I. (2000). Ciprofloxacin causes cytoskeletal changes and detachment of human and rat chondrocytes in vitro. Arch Toxicol, 73(10-11), 557-63. Retrieved December 20, 2008, from the PubMed database.

Posted on April 26, 2011, 13:35, Last updated on May 16, 2012, 15:54 | Antimicrobial Agents