Brand Name: Levaquin
Generic Name: levofloxacin
Manufacturer: Ortho-McNeil
Treatment Class: Anti-infective
Indication: Respiratory, skin, and upper and
lower urinary tract infections
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Antibiotic Levofloxacin Approved
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The fluoroquinolone antibiotic levofloxacin (Levaquin/Ortho-McNeil) has
received FDA approval for respiratory, skin, and upper 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 bacterial growth and
reproduction by blocking the enzyme DNA gyrase.
The antibiotic is active against gram-positive organisms (Enterococcus
faecalis, Staphylococcus aureus, Streptococcus pneumoniae, and
Streptococcus pyogenes), gram-negative organisms (Enterobacter cloacae,
Escherichia coli, Haemophilus influenzae and Haemophilus parainfluenzae,
Klebsiella pneumoniae, Legionella pneumophila, Moraxella catarrhalis,
Proteus mirabilis, and Pseudomonas aeruginosa), and other atypical
pathogens (Chlamydia pneumoniae and Mycoplasma pneumoniae).
Levofloxacin is indicated for acute maxillary sinusitis, acute bacterial
exacerbation of chronic bronchitis, community-acquired pneumonia,
uncomplicated skin and skin structure infections, complicated urinary tract
infections, acute pyelonephritis, cystitis, prostatitis, 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 infection (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 rates were 94 to 98% for S.
pneumoniae, H. influenzae, H. parainfluenzae, and M. catarrhalis; 88% for
S. aureus; and 100% for K. pneumoniae.
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 (bioavailability about 99%),
with peak plasma concentrations attained in 1 to 2 hours 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 levofloxacin can be taken without regard to meals.
The drug is 24 to 38% plasma protein bound and is widely distributed into
tissues, including lung tissue and blister fluid (concentration in lung
tissue is two- to five-fold higher than plasma concentrations).
Levofloxacin is excreted primarily as unchanged drug in the urine; it
undergoes glomerular filtration and proximal tubular secretion (cimetidine
and probenecid reduce levofloxacin clearance by 24% and 35%, respectively).
In clinical studies, terminal elimination 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 renal function status).
Patients with creatinine clearance 80 mL/minute or less should have the
dosage reduced to avoid accumulation.
Generally, 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 fluoroquinolones, it's a good
idea to avoid excessive exposure to sunlight. The drug should be
discontinued immediately if a skin eruption occurs.
Levofloxacin should be avoided in patients with central nervous system
(CNS) disorders that predispose to seizures, and diabetics on levofloxacin
should carefully monitor blood sugar.
Although levofloxacin has less affinity for cautions than do many other
fluoroquinolones, patients should be cautioned to take antacids, vitamin
and mineral supplements, and sucralfate 2 hours before or 2 hours after
levofloxacin administration.
Interaction studies have shown few or no problems with drugs such as
theophylline, warfarin, digoxin, and cyclosporine, although these agents do
interact with other fluoroquinolones. Caution is advised.
Shishido H et al. Drugs. 1995[Suppl. 2]:433-435.
Information from the manufacturer.
1997 VirSci Corporation.
As seen on PharmInfoNet (http://pharminfo.com)
Reprinted from the January/February 1997 issue of
Medical Sciences Bulletin [Med Sci Bull. 1997; 20(6)]
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