Levofloxacin is an advanced generation fluoroquinolone antibiotic, marketed by Ortho-McNeil under the trade name Levaquin in the United States.

Levofloxacin is an advanced generation fluoroquinolone antibiotic, marketed by Ortho-McNeil under the trade name Levaquin in the United States. In Europe, it is marketed by Sanofi-Aventis under the trade name Tavanic, in Chile as Gatigol by Alpes Selection, in India under the trade name Lebact marketed by Nicolas Piramal and in Asia it is marketed by Daiichi under the trade names Cravit and Levox. Levofloxacin was launched in the Japanese market in 1993, and thus has had more than 13 years of testing in efficacy and safety globally. Chemically, levofloxacin is the S-enantiomer (L-isomer) of ofloxacin, and has approximately twice the potency of ofloxacin, because the R+enantiomer (D-isomer) of ofloxacin is essentially inactive. In addition, the S-enantiomer (L-isomer) of ofloxacin, has substantially less toxicity. Like other fluoroquinolines, it works by inhibiting DNA gyrase, an enzyme that negatively supercoils DNA.

Levofloxacin is effective against a number of gram-positive and gram-negative bacteria. Because of its broad spectrum of action, levofloxacin is frequently prescribed empirically for a wide range of infections (e.g. pneumonia, urinary tract infection) before the specific causal organism is known. If the causal organism is identified, levofloxacin may be discontinued and the patient may be switched to an antibiotic with a narrower spectrum of activity. Levofloxacin is currently the only respiratory fluoroquinolone approved by the U.S. FDA for the treatment of nosocomial pneumonia.

Susceptible organisms

Gram-positive bacteria
Enterococcus faecalis (many strains are only moderately susceptible)
Staphylococcus aureus (methicillin-susceptible strains)
Staphylococcus epidermidis (methicillin-susceptible strains)
Staphylococcus saprophyticus
Streptococcus pneumoniae (including Multidrug-resistant strains, MDRSP)
Streptococcus pyogenes

Gram-negative bacteria
Enterobacter cloacae
Klebsiella pneumoniae
Pseudomonas aeruginosa
Escherichia coli
Legionella pneumophila
Serratia marcescens
Haemophilus influenzae
Moraxella catarrhalis
Haemophilus parainfluenzae
Proteus mirabilis
Campylobacter

Side Effects
This drug has similar side effects to all the other fluoroquinolone antibiotics. The most common side effects include: Nausea, stomach upset, loss of appetite, diarrhea, drowsiness, dizziness, headache, or trouble sleeping. The less common, but much more serious side effects are: Chest pain, change in the amount of urine, dark urine, easy bruising or bleeding, fainting, fast or irregular heartbeat, mood changes (e.g., suicidal thoughts or severe depression), persistent nausea or vomiting, persistent sore throat or fever, seizures, unusual fatigue, yellowing eyes and skin, white patches in the mouth, or a change in vaginal discharge.

As with all fluoroquinolones there are documented cases of spontaneous tendon rupture in less than 1 in 10,000 patients who have used this drug, the dosage in these patients were the prescribed two 500mg tablets a day, for five days. There are other cases of severe pain, and swelling in as little as two days. This is known as "quinolone-induced tendonopathy"

Other
Chlamydia pneumoniae
Mycoplasma pneumoniae
Peptostreptococcus sp.
More bacterial coverage is available as per prescribing information for levofloxacin in Japan