Title: Enrofloxacin
CAS Registry Number: 93106-60-6
CAS Name: 1-Cyclopropyl-7-(4-ethyl-1-piperazinyl)-6-fluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid
Additional Names: CFPQ
Manufacturers' Codes: Bay Vp 2674
Trademarks: Baytril (Bayer)
Molecular Formula: C19H22FN3O3
Molecular Weight: 359.39
Percent Composition: C 63.50%, H 6.17%, F 5.29%, N 11.69%, O 13.36%
Literature References: Fluorinated quinolone antibacterial. Prepn: K. Grohe et al., DE 3142854; eidem, US 4670444 (1983, 1987 both to Bayer AG); K. Grohe, H. Heitzer, Ann. 1987, 29. Use as plant fungicide: K. Grohe et al., US 4563459 (1986 to Bayer AG). Pharmacokinetics in calves: J. N. Davidson et al., Proc. West. Pharmacol. Soc. 29, 129 (1986); in chickens: G. M. Conzelman et al., ibid. 30, 393 (1987). Spectrofluorometric determn of residues in poultry tissues: T. B. Waggoner, M. C. Bowman, J. Assoc. Off. Anal. Chem. 70, 813 (1987). Toxicology and physical properties: P. Altreuther, Vet. Med. Rev. 2, 87 (1987). Series of articles on pharmacology, in vitro antibacterial activity and field trials: ibid. 90-140.
Properties: Pale yellow crystals, mp 219-221°. Slightly sol in water at pH 7. LD50 in male, female mice (mg/kg): >5000, 4336 orally; ~200, ~200 i.v.; in male rats, male rabbits (mg/kg): >5000, 500-800 orally (Altreuther).
Melting point: mp 219-221°
Toxicity data: LD50 in male, female mice (mg/kg): >5000, 4336 orally; ~200, ~200 i.v.; in male rats, male rabbits (mg/kg): >5000, 500-800 orally (Altreuther)
Therap-Cat-Vet: Antibacterial.
Ensulizole Enterogastrone Enterolactone Enteromycin Entprol

Enrofloxacin Structural Formulae.png
Systematic (IUPAC) name
1-Cyclopropyl-7-(4-ethyl-1-piperazinyl)-6-fluoro-1,4-dihydro-4-oxo-3-quinolonecarboxylic acid
Clinical data
AHFS/Drugs.com International Drug Names
Pregnancy cat. B3 (AU) C (US)
Legal status Prescription Only (S4) (AU) POM (UK)
Routes Oral, subcutaneous injection, topical (ear drops)
Pharmacokinetic data
Bioavailability 80% in dogs, 65-75% in sheep [1]
Metabolism Renal and non-renal[2]
Half-life 4–5 hours in dogs, 6 hours in cats, 1.5 - 4.5 hours in sheep.
Excretion Bile (70%); Renal (30%)[3]
CAS number 93106-60-6 YesY
ATCvet code QJ01MA90
PubChem CID 71188
ChemSpider 64326 YesY
KEGG D02473 YesY
ChEBI CHEBI:35720 YesY
Chemical data
Formula C19H22FN3O3 
Mol. mass 359.4
 YesY (what is this?)  (verify)

Enrofloxacin is a fluoroquinolone antibiotic sold by the Bayer Corporation under the trade name Baytril. Enrofloxacin is currently approved by the FDA for the treatment of individual pets and domestic animals in the United States. In September 2005, the FDA withdrew approval of Baytril for use in water to treat flocks of poultry, as this practice was noted to promote the evolution of fluoroquinolone-resistant strains of the bacterium Campylobacter, a human pathogen.[4] Fluoroquinolones such as ciprofloxacin are widely used in the treatment of human disease.

It is a bactericidal agent. The bactericidal activity of enrofloxacin is concentration-dependent, with susceptible bacteria cell death occurring within 20–30 minutes of exposure. Enrofloxacin has demonstrated a significant post-antibiotic effect for both Gram-negative and Gram-positive bacteria and is active in both stationary and growth phases of bacterial replication.