Generic Name levofloxacin =
Manufacturer Ortho-McNeil =
Treatment Class Anti-infective =
Indication Respiratory, skin, and upper and lower urinary tract infect=
ions =
Antibiotic Levofloxacin
Approved
Reprinted from the January/February 1997 issue=
of =
Medical Sciences Bulletin [Med Sci Bull. 1997; 2=
0(6)] =
The fluoroquinolone antibiotic levofloxacin (Levaquin/=
Ortho-McNeil)
has received FDA approval for respiratory, skin, and u=
pper and lower
urinary tract infections. Levofloxacin is the active l=
-isomer of Ortho's
quinolone ofloxacin (Floxin); isolating the pure l-isomer from the
racemic mixture of d- and l- rotatory isomers gives a =
compound with
enhanced efficacy, improved tolerability, and a longer=
duration of action.
As with other quinolones, levofloxacin inhibits bacter=
ial growth and
reproduction by blocking the enzyme DNA gyrase. The an=
tibiotic is
active against gram- positive organisms (Enterococcus =
faecalis,
Staphylococcus aureus, Streptococcus pneumoniae, and
Streptococcus pyogenes), gram-negative organisms (Ente=
robacter
cloacae, Escherichia coli, Haemophilus influenzae and =
Haemophilus
parainfluenzae, Klebsiella pneumoniae, Legionella pneu=
mophila,
Moraxella catarrhalis, Proteus mirabilis, and Pseudomo=
nas
aeruginosa), and other atypical pathogens (Chlamydia p=
neumoniae
and Mycoplasma pneumoniae). =
Levofloxacin is indicated for acute maxillary sinusiti=
s, acute bacterial
exacerbation of chronic bronchitis, community-acquired=
pneumonia,
uncomplicated skin and skin structure infections, comp=
licated urinary
tract infections, acute pyelonephritis, cystitis, pros=
tatitis, and sexually
transmitted disease (urethral and cervical gonorrhea, =
nongonococcal
urethritis and cervicitis, and mixed infections of the=
urethra and cervix). In
two clinical studies of patients with respiratory infe=
ction (total: 854
patients), levofloxacin 500 mg orally or intravenously=
(IV) once daily for
7 to 14 days showed clinical success rates (cure plus =
improvement) of
93% and 95%. Specifically, microbiologic eradication r=
ates were 94 to
98% for S. pneumoniae, H. influenzae, H. parainfluenza=
e, and M.
catarrhalis; 88% for S. aureus; and 100% for K. pneumo=
niae.
Eradication rates for atypical pneumonia were 96% for =
Chlamydia and
Mycoplasma, and 70% for Legionella. =
Levofloxacin is administered IV in a dose of 500 mg by=
60-minute
infusion every 24 hours, or orally as a 250- or 500-mg=
tablet once daily.
It is rapidly and completely absorbed orally (bioavail=
ability about 99%),
with peak plasma concentrations attained in 1 to 2 hou=
rs and
steady-state levels achieved within 48 hours. Food has=
little effect on
absorption-it prolongs the time to peak concentration =
by about 1 hour
and decreases peak concentration by about 14%-so levof=
loxacin can be
taken without regard to meals. The drug is 24 to 38% p=
lasma protein
bound and is widely distributed into tissues, includin=
g lung tissue and
blister fluid (concentration in lung tissue is two- to=
fivefold higher than
plasma concentrations). =
Levofloxacin is excreted primarily as unchanged drug i=
n the urine; it
undergoes glomerular filtration and proximal tubular s=
ecretion (cimetidine
and probenecid reduce levofloxacin clearance by 24% an=
d 35%,
respectively). In clinical studies, terminal eliminati=
on half-life was 6 to 8
hours (6 hours in females and younger subjects, and 7-=
8 hours in males
and older subjects, with differences probably due to r=
enal function
status). Patients with creatinine clearance 80 mL/minu=
te or less should
have the dosage reduced to avoid accumulation. General=
ly,
pharmacokinetics are not influenced by age, sex, race,=
liver function
status, or the occurrence of bacterial infection. =
Phototoxic reactions have been rare with levofloxacin =
therapy (occurring
in less than 0.1% of patients), but as for all fluoroq=
uinolones, it's a good
idea to avoid excessive exposure to sunlight. The drug=
should be
discontinued immediately if a skin eruption occurs. Le=
vofloxacin should
be avoided in patients with central nervous system (CN=
S) disorders that
predispose to seizures, and diabetics on levofloxacin =
should carefully
monitor blood sugar. Although levofloxacin has less af=
finity for cations
than do many other fluoroquinolones, patients should b=
e cautioned to
take antacids, vitamin and mineral supplements, and su=
cralfate 2 hours
before or 2 hours after levofloxacin administration. I=
nteraction studies
have shown few or no problems with drugs such as theop=
hylline,
warfarin, digoxin, and cyclosporine, although these ag=
ents do interact
with other fluoroquinolones. Caution is advised. (Shis=
hido H et al. Drugs.
1995[Suppl. 2]:433-435. Information from the manufactu=
rer.) =
=A9 1997 VirSci Corporation. All rights reserved.
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Last modified on Tuesday, 11-Mar-97 07:01:56.
