Levofloxacin is a chemical compound, fluoroquinolone (belongs to the third generation of tricyclic quinolones), an antibacterial and antimicrobial antibiotic, with broad-spectrum bactericidal activity against most Gram-negative bacteria (e.g. Escherichia coli ATCC 25922, Proteus hauseri ATCC 15442), many Gram-positive bacteria (e.g. Staphylococcus aureus ATCC 6538) and some anaerobes.

Take only under medical supervision

It comes in the form of a fine powder with coloration ranging from white to yellow-orange.

It was approved by the U.S. FDA in the late 1990s and is used to treat infections primarily located in:

• lungs
• urinary tract
• prostate
• skin, muscles
• facial sinuses

The scientific literature attributes to the fluoroquinolones levofloxacin and moxifloxacin, the role of first defenders in the management of pneumonia (1).  

Recently, this study proposed fluoroquinolones due to their immunomodulatory properties, favorable pharmacokinetics, and excellent safety profile as adjuvants in the treatment of patients presenting with COVID-19 (2).

Antibacterial prophylaxis, designed to reduce bacterial infections in more than 40% of pediatric patients with acute myeloid leukemia, has turned toward levofloxacin for its effects in reducing the incidence of febrile neutropenia and bacterial infections (3).

This study evaluated the safety and efficacy of levofloxacin as bacterial prophylaxis in pediatric and young adult patients undergoing allogeneic or autologous hematopoietic stem cell transplantation at a single pediatric center. The findings of the study confirm the validity of levofloxacin prophylaxis significantly associated with a decrease in bloodstream bacterial infection and was not associated with an increased risk of Clostridioides difficile infection rates, increased incidence of acute graft-versus-host disease, and incidence of multidrug-resistant organisms (4).

Today, third- (levofloxacin) and fourth-generation fluoroquinolones (moxifloxacin and gatifloxacin) represent the most viable antibacterial agents for topical use in ophthalmology even though they involve poor bioavailability because of the rapid precorneal elimination of the toxin. Sulfobutyl-ether-β-cyclodextrin is a suitable polyanion to produce polymeric chitosan nanospheres with good properties for ocular administration of levofloxacin (5).

Like all drugs it can cause side effects. Always ask the physician.

Levofloxacin studies

Typical optimal characteristics of the commercial powder product levofloxacin

Appearance	Powder white to pale yellow/orange
Melting point-Melting range	18-227 °C (424-441 °F)
Boiling point-Boiling range	572 °C (1062 °F)
Flash point	> 110 °C (> 230 °F)
Purity(HPLC)	min. 98.0 area%
Purity(Nonaqueous Titration)	min. 96.0 %
Specific rotation [a]20/D	-63.0 to -70.0 deg(C=5, CHCl3)
Specific Rotation	-66° (C=5,CHCl3)

Where to buy Levofloxacin powder

• Molecular Formula: C₁₈H₂₀FN₃O₄
• Molecular Weight: 361.37 g/mol
• CAS: 100986-85-4
• UNII RIX4E89Y14
• EC Number: 
• DSSTox Substance ID: DTXSID0041060
• MDL number  MFCD00865049
• PubChem Substance ID 329756033    57648297
• Beilstein  7327015
• InChl  1S/C18H20FN3O4/c1-10-9-26-17-14-11(16(23)12(18(24)25)8-22(10)14)7-13(19)15(17)21-5-3-20(2)4-6-21/h7-8,10H,3-6,9H2,1-2H3,(H,24,25)/t10-/m0/s1
• InChI Key      GSDSWSVVBLHKDQ-JTQLQIEISA-N
• SMILES    CC1COC2=C3N1C=C(C(=O)C3=CC(=C2N4CCN(CC4)C)F)C(=O)O
• IUPAC (2S)-7-fluoro-2-methyl-6-(4-methylpiperazin-1-yl)-10-oxo-4-oxa-1-azatricyclo[7.3.1.05,13]trideca-5(13),6,8,11-tetraene-11-carboxylic acid
• ChEBI    63598
• NSC   758709
• NACRES  NA.85

Synonyms: 

• (3S)-9-fluoro-3-methyl-10-(4-methylpiperazin-1-yl)-7-oxo-2,3-dihydro-7H-[1,4]oxazino [2,3,4-ij]quinoline-6-carboxylic acid)
• Levaquin
• Ofloxacin, (S)-Isomer
• (−)-Ofloxacin

References__________________________________________________________________

(1) Metlay JP, Waterer GW, Long AC, Anzueto A, Brozek J, Crothers K, Cooley LA, Dean NC, Fine MJ, Flanders SA, Griffin MR, Metersky ML, Musher DM, Restrepo MI, Whitney CG. Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America. Am J Respir Crit Care Med. 2019 Oct 1;200(7):e45-e67. doi: 10.1164/rccm.201908-1581ST.

(2) Karampela I, Dalamaga M. Could Respiratory Fluoroquinolones, Levofloxacin and Moxifloxacin, Prove to be Beneficial as an Adjunct Treatment in COVID-19? Arch Med Res. 2020 Oct;51(7):741-742. doi: 10.1016/j.arcmed.2020.06.004. 

(3) McCormick M, Friehling E, Kalpatthi R, Siripong N, Smith K. Cost-effectiveness of levofloxacin prophylaxis against bacterial infection in pediatric patients with acute myeloid leukemia. Pediatr Blood Cancer. 2020 Oct;67(10):e28469. doi: 10.1002/pbc.28469.

(4) Gardner JC, Courter JD, Dandoy CE, Davies SM, Teusink-Cross A. Safety and efficacy of prophylactic levofloxacin in pediatric and adult hematopoietic stem cell transplant patients. Transplant Cell Ther. 2021 Dec 4:S2666-6367(21)01404-4. doi: 10.1016/j.jtct.2021.11.017. 

(5) De Gaetano F, Marino A, Marchetta A, Bongiorno C, Zagami R, Cristiano MC, Paolino D, Pistarà V, Ventura CA. Development of Chitosan/Cyclodextrin Nanospheres for Levofloxacin Ocular Delivery. Pharmaceutics. 2021 Aug 19;13(8):1293. doi: 10.3390/pharmaceutics13081293.

Compendium of the most significant studies with reference to properties, intake, effects.

Kloskowski T, Szeliski K, Fekner Z, Rasmus M, Dąbrowski P, Wolska A, Siedlecka N, Adamowicz J, Drewa T, Pokrywczyńska M. Ciprofloxacin and Levofloxacin as Potential Drugs in Genitourinary Cancer Treatment-The Effect of Dose-Response on 2D and 3D Cell Cultures. Int J Mol Sci. 2021 Nov 4;22(21):11970. doi: 10.3390/ijms222111970.

Abstract. Introducing new drugs for clinical application is a very difficult, long, drawn-out, and costly process, which is why drug repositioning is increasingly gaining in importance. The aim of this study was to analyze the cytotoxic properties of ciprofloxacin and levofloxacin on bladder and prostate cell lines in vitro.

Podder V, Sadiq NM. Levofloxacin. 2021 Sep 22. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–.

Abstract. Levofloxacin is FDA-approved for the treatment of nosocomial pneumonia, community-acquired pneumonia, acute bacterial rhinosinusitis, acute bacterial exacerbation of chronic bronchitis, acute bacterial prostatitis, acute pyelonephritis, urinary tract infection, skin or skin structure infections, prophylaxis, and treatment of plaque due to Yersinia pestis, and to reduce the incidence of disease progression of inhalational anthrax. 

Deshpande D, Pasipanodya JG, Mpagama SG, Bendet P, Srivastava S, Koeuth T, Lee PS, Bhavnani SM, Ambrose PG, Thwaites G, Heysell SK, Gumbo T. Levofloxacin Pharmacokinetics/Pharmacodynamics, Dosing, Susceptibility Breakpoints, and Artificial Intelligence in the Treatment of Multidrug-resistant Tuberculosis. Clin Infect Dis. 2018 Nov 28;67(suppl_3):S293-S302. doi:

Abstract. The levofloxacin dose of 25 mg/kg or 1500 mg/day was adequate for replacement of high-dose moxifloxacin in treatment of multidrug-resistant tuberculosis.

Rafat C, Debrix I, Hertig A. Levofloxacin for the treatment of pyelonephritis. Expert Opin Pharmacother. 2013 Jun;14(9):1241-53. doi: 10.1517/14656566.2013.792805.

Abstract. Levofloxacin has achieved satisfactory bacterial eradication rates and clinical success across all available trials, similar to the antibiotic comparator. 

Wrońska N, Majoral JP, Appelhans D, Bryszewska M, Lisowska K. Synergistic Effects of Anionic/Cationic Dendrimers and Levofloxacin on Antibacterial Activities. Molecules. 2019 Aug 9;24(16):2894. doi: 10.3390/molecules24162894.

Abstract. Despite the numerous studies on dendrimers for biomedical applications, the antibacterial activity of anionic phosphorus dendrimers has not been explored. In our research, we evaluated the antibacterial activity of modified polycationic and polyanionic dendrimers in combination with levofloxacin 

Grillon A, Schramm F, Kleinberg M, Jehl F. Comparative Activity of Ciprofloxacin, Levofloxacin and Moxifloxacin against Klebsiella pneumoniae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia Assessed by Minimum Inhibitory Concentrations and Time-Kill Studies. PLoS One. 2016 Jun 3;11(6):e0156690. doi: 10.1371/journal.pone.0156690.

Abstract. The aim of this study was to compare the in vitro susceptibility of Klebsiella pneumoniae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia to three fluoroquinolones. 

Sitovs A, Sartini I, Giorgi M. Levofloxacin in veterinary medicine: a literature review. Res Vet Sci. 2021 Jul;137:111-126. doi: 10.1016/j.rvsc.2021.04.031.

Abstract. Levofloxacin is also used in veterinary medicine, however its use is limited: it is completely banned for veterinary use in the EU, and used extralabel in only companion animals in the USA. 

 Bientinesi R, Murri R, Sacco E. Efficacy and safety of levofloxacin as a treatment for complicated urinary tract infections and pyelonephritis. Expert Opin Pharmacother. 2020 Apr;21(6):637-644. doi: 10.1080/14656566.2020.1720647. 

Abstract. La levofloxacina è un antibatterico fluorochinolonico che è diventato uno dei capisaldi della terapia antibiotica delle infezioni del tratto urinario complicate e della pielonefrite sin dalla sua introduzione nel 1990 a causa del suo eccezionale profilo farmacocinetico (PK) e farmacodinamico (PD). Tuttavia, l'emergere di una diffusa resistenza ai fluorochinoloni negli ultimi dieci anni ha spinto gli investigatori a riesaminare il suo posto nel trattamento delle infezioni del tratto urinario.

Brunetti L, Lee SM, Nahass RG, Suh D, Miao B, Bucek J, Kim D, Kim OK, Suh DC. The risk of cardiac events in patients who received concomitant levofloxacin and amiodarone. Int J Infect Dis. 2019 Jan;78:50-56. doi: 10.1016/j.ijid.2018.10.017. 

Abstract. Levofloxacin and amiodarone are both known to prolong the QT interval. This study was conducted to estimate the risk of cardiac events in patients receiving concomitant levofloxacin and amiodarone.