Ciprofloxacin has in vitro activity against a wide range of gram-negative and gram-positive organisms. The bactericidal action of ciprofloxacin results from inhibition of topoisomerase II (DNA gyrase) and topoisomerase IV (both Type II topoisomerases), which are required for bacterial DNA replication, transcription, repair, and recombination. The mechanism of action of quinolones, including ciprofloxacin, is different from that of other antimicrobial agents such as beta-lactams, macrolides, tetracyclines, or aminoglycosides; therefore, organisms resistant to these drugs may be susceptible to ciprofloxacin. There is no known cross-resistance between ciprofloxacin and other classes of antimicrobials.
The determination of dosage for any particular patient must take into consideration the severity and nature of the infection, the susceptibility of the causative organism, the integrity of the patient’s host-defense mechanisms, and the status of renal function and hepatic function.
The duration of treatment depends upon the severity of infection. The usual duration is 7 to 14 days; however, for severe and complicated infections more prolonged therapy may be required. Ciprofloxacin should be administered at least 2 hours before or 6 hours after magnesium/aluminum antacids, or sucralfate, Videx ®* (didanosine) chewable/buffered tablets or pediatric powder for oral solution, other highly buffered drugs, or other products containing calcium, iron or zinc.
Conversion of I.V. to Oral Dosing in Adults
Patients whose therapy is started with ciprofloxacin I.V. may be switched to Ciprofloxacin Tablets when clinically indicated at the discretion of the physician (see CLINICAL PHARMACOLOGY and table below for the equivalent dosing regimens).
Adults with Impaired Renal Function
Ciprofloxacin is eliminated primarily by renal excretion; however, the drug is also metabolized and partially cleared through the biliary system of the liver and through the intestine. These alternate pathways of drug elimination appear to compensate for the reduced renal excretion in patients with renal impairment. Nonetheless, some modification of dosage is recommended, particularly for patients with severe renal dysfunction. The following table provides dosage guidelines for use in patients with renal impairment:
Elderly: No adjustment needed in patients with normal renal function
Hemodialysis: (IV): 200-400mg q24h or 200mg q12h. Schedule dose after dialysis on dialysis days. (Oral): 250mg q12h or 250-500mg q24h. Schedule dose after dialysis on dialysis days.
Tablet, extended release [film coated] (Cipro® XR): 500 mg [equivalent to ciprofloxacin hydrochloride 287.5 mg and ciprofloxacin base 212.6 mg]; 1000 mg [equivalent to ciprofloxacin hydrochloride 574.9 mg and ciprofloxacin base 425.2 mg]
| Dosing: 400 mg po/IV qd
[CRCL >40]: No changes.
[<40 ]: 400mg x 1, then 200mg qd.
Hemodialysis: 400 mg x 1, then 200mg qd. (On dialysis days, schedule dose after dialysis.).
PD: 400 mg x 1, then 200mg qd
| Mechanism of Action
Levofloxacin is the L-isomer of the racemate, ofloxacin, a quinolone antimicrobial agent. The antibacterial activity of ofloxacin resides primarily in the L-isomer. The mechanism of action of levofloxacin and other fluoroquinolone antimicrobials involves inhibition of bacterial topoisomerase IV and DNA gyrase (both of which are type II topoisomerases), enzymes required for DNA replication, transcription, repair and recombination.
Inhalational anthrax: 500 mg every 24 hours for 60 days, beginning as soon as possible after exposure
Prostatitis (chronic bacterial): 500 mg every 24 hours for 28 days
Urinary tract infections:
Moxifloxacin has in vitro activity against a wide range of Gram-positive and Gram-negative microorganisms. The bactericidal action of moxifloxacin results from inhibition of the topoisomerase II (DNA gyrase) and topoisomerase IV required for bacterial DNA replication, transcription, repair, and recombination. It appears that the C8-methoxy moiety contributes to enhanced activity and lower selection of resistant mutants of Gram-positive bacteria compared to the C8-H moiety. The presence of the bulky bicycloamine substituent at the C-7 position prevents active efflux, associated with the NorA or pmrA genes seen in certain Gram-positive bacteria.
The mechanism of action for quinolones, including moxifloxacin, is different from that of macrolides, beta-lactams, aminoglycosides, or tetracyclines; therefore, microorganisms resistant to these classes of drugs may be susceptible to moxifloxacin and other quinolones. There is no known cross-resistance between moxifloxacin and other classes of antimicrobials.
INDICATIONS AND USAGE
Acute Bacterial Sinusitis caused by Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis.
Acute Bacterial Exacerbation of Chronic Bronchitis caused by Streptococcus pneumoniae, Haemophilus influenzae, Haemophilus parainfluenzae, Klebsiella pneumoniae, methicillin-susceptible Staphylococcus aureus, or Moraxella catarrhalis.
Community Acquired Pneumonia caused by Streptococcus pneumoniae (including multi-drug resistant strains*), Haemophilus influenzae, Moraxella catarrhalis, methicillin-susceptible Staphylococcus aureus, Klebsiella pneumoniae, Mycoplasma pneumoniae, or Chlamydia pneumoniae.
* MDRSP, Multi-drug resistant Streptococcus pneumoniae includes isolates previously known as PRSP (Penicillin-resistant S. pneumoniae), and are strains resistant to two or more of the following antibiotics: penicillin (MIC ≥ 2 µg/mL), 2nd generation cephalosporins (e.g., cefuroxime), macrolides, tetracyclines, and trimethoprim/sulfamethoxazole.
Uncomplicated Skin and Skin Structure Infections caused by methicillin-susceptible Staphylococcus aureus or Streptococcus pyogenes.
Complicated Intra-Abdominal Infections including polymicrobial infections such as abscess caused by Escherichia coli, Bacteroides fragilis, Streptococcus anginosus, Streptococcus constellatus, Enterococcus faecalis, Proteus mirabilis, Clostridium perfringens, Bacteroides thetaiotaomicron, or Peptostreptococcus species.
Complicated Skin and Skin Structure Infections caused by methicillin-susceptible Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, or Enterobacter cloacae (See Clinical Studies).
Dosing (Adults): 400 mg orally or IV q24h.
Acute bacterial sinusitis: Oral, I.V.: 400 mg every 24 hours for 10 days.
Renal Dosing: No adjustment necessary. Hemo: No specific guidelines available.
Supplied: Tablet: 400mg. Avelox® ABC Pack: contains 5 unit dose 400mg tablets. IV (premixed): 400mg/250 ml NS. Ophthalmic soln ( Vigamox ®): 0.5% (3 ml).
| Oral: Adults:
Urinary tract infections: 400 mg twice daily for 3-21 days depending on severity of infection or organism sensitivity; maximum: 800 mg/day
Uncomplicated gonorrhea: 800 mg as a single dose (CDC recommends as an alternative regimen to ciprofloxacin or ofloxacin)
Prostatitis: 400 mg every 12 hours for 4 weeks
Dosing interval in renal impairment: Clcr 10-30 mL/minute: Urinary tract infections: Administer 400 mg every 24 hours
National Institutes of Health, U.S. National Library of Medicine, DailyMed Database.
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