Enrofloxacin

Enrofloxacin: Uses, Dosage and Side Effects

Overview

• Enrofloxacin is a concentration-dependent antibiotic that prevents bacterial DNA gyrase activity.
• Pulse dosing strategies may be helpful against Gram-negative bacteria in particular.

Uses of Enrofloxacin

• Fluoroquinolones should be reserved for infections where culture and sensitivity testing indicate a clinical response and lower-tier antimicrobials fail.
• Active against Mycoplasma, Pasteurella, Staphylococcus, Pseudomonas aeruginosa, Klebsiella, Escherichia coli, Mycobacterium, Proteus, and Salmonella.
• Poor against obligatory anaerobes.
• Fluoroquinolones treat soft tissue, urogenital (including prostate), and cutaneous infections because they are lipophilic and reach high cell concentrations.
• Enrofloxacin, clarithromycin, and rifampin treat non-tubercular mycobacterial disease.
• In severe sepsis, i.v. the administration is allowed.
• Dilute to 10 times the volume with 0.9% sodium chloride and deliver slowly (35–45 minutes) because the carrier contains potassium.

Dose of Enrofloxacin in Dogs and Cats

Dogs:

• 5 mg/kg s.c. q24h. Higher doses (10 mg/kg q24h) should be considered for certain sites, including prostatitis.
• Even higher doses may be necessary for certain isolates of Pseudomonas aeruginosa.
• Contact the manufacturer to discuss individual cases.

Cats:

• 5 mg/kg s.c. q24h; 2.5 mg/kg p.o. q12h or 5 mg/kg p.o. q24h

Side Effects of Enrofloxacin in Dogs and Cats

• There have been cases of irreversible retinal blindness in cats at dosing rates higher than those currently recommended, although at least one case was dosed at the 5 mg/kg q24h rate.
• Enrofloxacin should be used with caution in epileptic animals until further information is available, as concurrent administration of NSAIDs and enrofloxacin increases CNS adverse effects in humans.
• Accurate body weight and use of a 1 ml syringe facilitate careful administration in cats, and doses greater than 5 mg/kg/day are not recommended but have been used in cases of severe sepsis.
• If this route is chosen, the drug should be diluted 10 times with 0.9% sodium chloride and administered slowly, as the vehicle contains potassium (ideally over 35–45 minutes).

Contraindications of Enrofloxacin in Dogs and Cats

• Fluoroquinolones are relatively contraindicated in growing dogs, as cartilage abnormalities have been reported in young dogs (but not cats).
• Enrofloxacin is not authorized in cats <8 weeks of age; dogs <1 year of age; large-breed dogs <18 months of age.

Some Notes:

• Cation-containing absorbents and antacids can bind fluoroquinolones and inhibit their absorption.
• Sucralfate and zinc salts may also impede absorption.
• Separate dose by at least 2 hours.
• Plasma theophylline concentrations rise with fluoroquinolones.
• Fluoroquinolone clearance may be reduced by cimetidine, thus use with caution.
• Some fluoroquinolones may decrease the metabolism and increase the nephrotoxicity of ciclosporin and tacrolimus in humans, so concurrent use in animals should be avoided until more research is done.