Quinolones and fluoroquinolones are bactericidal drugs, eradicating bacteria by interfering with DNA replication.
Like other fluoroquinolones, enoxacin functions by inhibiting bacterial DNA gyrase and topoisomerase IV. The inhibition of these enzymes prevents bacterial DNA replication, transcription, repair and recombination.[4][5] Enoxacin inhibits the expression of the microRNA mir-34-5p, leading to an increase in the lifespan of the nematode C. elegans.[6]
Enoxacin is active against many Gram-positive bacteria.[note 2] The quinolone is also active against Gram-negative bacteria[note 3][7][8]
Pharmacokinetics
After oral administration enoxacin is rapidly and well absorbed from the gastrointestinal tract. The antibiotic is widely distributed throughout the body and in the different biological tissues. Tissue concentrations often exceed serum concentrations. The binding of enoxacin to serum proteins is 35 to 40%.
The serum elimination half-life, in subjects with normal renal function, is approximately 6 hours. Approximately 60% of an orally administered dose is excreted in the urine as unchanged drug within 24 hours.[9][10]
A small amount of a dose of drug administered is excreted in the bile.[11] High concentrations of the fluoroquinolone are reached in the urinary tract and this fact ensures an antibacterial effect continued over time, particularly in this district.
Enoxacin, like other fluoroquinolones, is known to trigger seizures or lower the seizure threshold.[15] The compound should not be administered to patients with epilepsy or a personal history of previous convulsive attacks as it may promote the onset of these disorders.[16]
Contraindications
Enoxacin is contraindicated in subjects with a history of hypersensitivity to the substance or any other member of the quinolone class, or any component of the medicine. Enoxacin, like other fluoroquinolones, can cause degenerative changes in weightbearing joints of young animals. The compound should only be used in children
when the expected benefits are outweigh the risks.[17][18]
Interactions
Fenbufen: co-administration with some quinolones, including enoxacin may increase the risk of seizures. For this reason, concomitant administration of fenbufen and the quinolone should be avoided, as a precaution.[19][20][21][22]
Theophylline: in patients treated concurrently with theophylline and enoxacin, concentrations of the methylxanthine in plasma arise due to a reduced metabolic clearance of theophylline.[23][24][25][26]
Ranitidine, sucralfate, antacids containing magnesium or aluminium, supplements containing calcium, iron, or zinc: co-administration with these substances can lead to therapeutic failure of the antibiotic due to decreased absorption by the intestinal tract. For example, magnesium or aluminium antacids turn enoxacin into insoluble salts that are not readily absorbed by the gastroenteric tract.[27][28][29]
Notes
^Enoxacin is sold under the following trade names: Almitil, Bactidan, Bactidron, Comprecin, Enoksetin, Enoxen, Enroxil, Enoxin, Enoxor, Flumark, Penetrex, Gyramid, Vinone.
^Mogabgab WJ (December 1991). "Recent developments in the treatment of sexually transmitted diseases". The American Journal of Medicine. 91 (6A): 140S–144S. doi:10.1016/0002-9343(91)90327-T. PMID1767802.
^Wise R, Andrews JM, Danks G (March 1984). "In-vitro activity of enoxacin (CL-919), a new quinoline derivative, compared with that of other antimicrobial agents". The Journal of Antimicrobial Chemotherapy. 13 (3): 237–244. doi:10.1093/jac/13.3.237. PMID6586712.
^Wise R, Lister D, McNulty CA, Griggs D, Andrews JM (1986). "The comparative pharmacokinetics and tissue penetration of four quinolones including intravenously administered enoxacin". Infection. 14 (Suppl 3): S196–S202. doi:10.1007/bf01667843. PMID3463542. S2CID21959049.
^Flowerdew A, Walker E, Karran SJ (1985). Evaluation of biliary pharmacokinetics of oral enoxacin, a new quinolone antibiotic. 14th International Congress of Chemotherapy. Kyoto. p. 42.
^Huttunen M, Kunnas K, Saloranta P (February 1988). "Enoxacin treatment of urinary tract infections in elderly patients". The Journal of Antimicrobial Chemotherapy. 21 (Suppl B): 105–111. doi:10.1093/jac/21.suppl_b.105. PMID3162900.
^Sano M, Kawakatsu K, Ohkita C, Yamamoto I, Takeyama M, Yamashina H, et al. (1988). "Effects of enoxacin, ofloxacin and norfloxacin on theophylline disposition in humans". European Journal of Clinical Pharmacology. 35 (2): 161–165. doi:10.1007/bf00609246. PMID3191935. S2CID1513011.
^Misiak PM, Eldon MA, Toothaker RD, Sedman AJ (January 1993). "Effects of oral cimetidine or ranitidine on the pharmacokinetics of intravenous enoxacin". Journal of Clinical Pharmacology. 33 (1): 53–56. doi:10.1002/j.1552-4604.1993.tb03903.x. PMID8429114. S2CID35219055.