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Ciprobay
Broad-spectrum antibiotic
Composition
Active constituent:
Ciprobay 250:
1 film-coated tablet contains 291 mg ciprofloxacin hydrochloride
monohydrate, corresponding to 250 mg ciprofloxacin.
Ciprobay 500:
1 film-coated tablet contains 582 mg ciprofloxacin hydrochloride
monohydrate, corresponding to 500 mg ciprofloxacin.
Ciprobay 750:
1 film-coated tablet contains 873 mg ciprofloxacin hydrochloride
monohydrate, corresponding to 750 mg ciprofloxacin.
Further constituents:
microcrystalline cellulose, maize starch, poly(1-vinyl-2-pyrrolidone)
crosslinked, highly dispersed silicon dioxide, magnesium stearate,
methylhydroxypropylcellulose, macrogol 4000, titanium dioxide (E171).
Properties
Ciprofloxacin is a synthetic broad spectrum quinolone antibacterial agent. (ATC
code: J01MA02)
Mechanism of Action
Ciprofloxacin has in-vitro against virtually all Gram-negative and
Gram-positive organisms. The bactericidal action of ciprofloxacin results
from inhibition of bacterial type II topoisomerases (DNA gyrase and
topoisomerase IV), which are required for bacterial DNA replication,
transcription, repair, and recombination.
Mechanism of Resistance
In vitro resistance to ciprofloxacin is commonly due to mutations in
bacterial topoisomerases and develops slowly through multiple-step
mutations. Ciprofloxacin resistance due to spontaneous mutations occurs at a
frequency of between <10-s to 10-6. Cross-resistance among fluoroquinolones
may occur when resistance arises through mutations. Single mutations may
result in reduced susceptibility rather than clinical resistance, but
multiple mutations generally result in clinical resistance to ciprofloxacin
and cross-resistance across the quinolone class. Bacterial impermeability
and/or expression of efflux pumps may impact ciprofloxacin susceptibility.
Plasmid-mediated resistance encoded by the gnrgene has been reported.
Resistance mechanisms that inactive penicillins, cephalosporins,
aminoglycosides, macrolides, and tetracyclines do not interfere with the
antibacterial activity of ciprofloxacin and there is no known
cross-resistance between ciprofloxacin and other classes of antimicrobials.
Organisms resistant to these drugs may be susceptible to ciprofloxacin.
The minimal bactericidal concentration (MBC) generally does not exceed the
minimal inhibitory concentration (MIC) by more than a factor of 2.
In vitro Susceptibility Testing
Interpretative criteria for the susceptibility testing of ciprofloxacin
approved by the European Committee on Antimicrobial Susceptibility Testing (EUCAST)
are presented in the below table.
European Committee on
Antimicrobial Susceptibility Testing (EUCAST)
Clinical MIC (µg/L) Breakpoints
for Ciprofloxacin
|
Organism |
Susceptible
[mg/L] |
Resistant
[mg/L] |
|
Enterobacteriaceae
Pseudomonas
Staphylococcus1
Streptococcus
pneumoniae2
Haemophilus influenzae
and Moraxella catarrhalis3
Neisseria gonorrhoeae
Non-species related
breakpoints4 |
≤0.5
≤0.5
≤1
≤0.125
≤0.5
≤0.03
≤0.5 |
>1
>1
>1
>2
>0.5
>0.06
>1 |
1. Staphylococcus spp. - breakpoints for ciprofloxacin and ofloxacin relate
to high dose therapy.
2. Streptococcus pneumoniae - wild type S. pneumoniae are not considered
susceptible to ciprofloxacin or ofloxacin and are therefore categorized as
intermediate.
3. Strains with MIC values above the S/I breakpoint are very rare or not yet
reported. The identification and antimicrobial susceptibility tests on any
such isolate must be repeated and if the result is confirmed the isolate
sent to a reference laboratory. Until there is evidence regarding clinical
response for confirmed isolates with MIC above the current resistant
breakpoint (in italics) they should be reported resistant. Haemophilus/
Moraxella-fluoroquinolone low-level resistance (ciprofloxacin MICs of 0.125
- 0.5 mg/L) may occur in Haemophilus influenzae. There is no evidence that
low-level resistance is of clinical importance in respiratory tract
infections with H. influenzae.
4. Non-species related breakpoints have been determined mainly on the basis
of PK/PD data and are independent of MIC distributions of specific species.
They are for use only for species that have not been given a
species-specific breakpoint and not for those species where susceptibility
testing is not recommended (marked with - or IE in the table).
Clinical and Laboratory Standards Institute™ (CLSI, formerly NCCLS)
breakpoints are presented in the below table for MIC testing (mg/L) or disk
diffusion testing (zone diameter [mm]) using a 5 µg ciprofloxacin disk.
Clinical and Laboratory Standards Institute™ (CLSI)
MIC (µg/L) and Disk Diffusion (mm) Breakpoints (CLSI Document M100-S17,
2007)
|
Organism |
Susceptible |
Intermediate |
Resistant |
|
Enterobacteriaceae |
<1a
>21b |
2a
16-20b |
>4a
<15b |
|
Pseudomonas aeruginosa
and
other non-Enterobacteriaceae |
<1a
>21b |
2a
16-20b |
>4a
<15b |
|
Staphylococcus spp |
<1a
>21b |
2a
16-20b |
>4a
<15b |
|
Enterococcus spp. |
<1a
>21b |
2a
16-20b |
>4a
<15b |
|
Haemophilus spp. |
<1c
>21d |
--
-- |
--
-- |
|
Neisseria gonorhoeae |
<0.06e
<41e |
0.12 - 0.5e
28 - 40e |
>1e
<27e |
a This interpretive standard is applicable only to broth dilution tests
using cation adjusted Mueller-Hinton broth (CAMHB) incubated in ambient air
at 33 to 35°C (do not exceed 35°C) for 16 - 20 hours
b This interpretive standard is applicable only to disc diffusion tests
using Mueller-Hinton agar incubated in ambient air at 33 to 35°C (do not
exceed 35°C) for 16 -18 hours
c This interpretive standard is applicable only to broth dilution
susceptibility tests with Haemophilus influenzae and Haemophilus
parainfluenzae using Haemophilus test medium (HTM) broth incubated in
ambient air at 35°C ± 2°C for 20 - 24 hours
d This interpretive standard is applicable only to disk diffusion tests with
H. influenzae and H. parainfluenzae using HTM incubated in 5%
CO2 at 35°C ± 2°C for 16 -18
hours
e This interpretive standard is applicable only to agar based susceptibility
tests using GC agar and 1% defined growth supplement at 36 ± 1°C (not to
exceed 37°C) in 5% CO2 for 20 - 24 hours.
Influence of Test Conditions
Inoculum size has only a slight effect on in vitro susceptibility testing in
the presence of very high numbers), whereas growth media and oxygen tension
have no significant influence. Ciprofloxacin is slightly less active when
tested under acidic pH conditions.
In vitro Susceptibility to Ciprofloxacin
The prevalence of acquired resistance may vary geographically and with time
for selected species and local information of resistance is desirable,
particularly when treating severe infections. As necessary, expert advice
should be sought where the local prevalence of resistance is such that
utility of the agent, in at least some types of infections, is questionable.
Ciprofloxacin has been shown to be active
in vitro against susceptible
strains of the micro-organisms listed below:
| Aerobic Gram-positive Microorganisms |
| Bacillus anthracis |
|
| Enterococcus faecalis |
(many strains are only moderately susceptible) |
| Staphylococcus aureus |
(methicillin-susceptible) |
| Staphylococcus saprophyticus |
|
| Streptococcus pneumoniae |
|
| Aerobic Gram-negative Microorganisms |
| Burkholderia cepacia |
Morganella morganii |
| Campylobacter spp. |
Neisseria gonorrhoeae |
| Citrobacter freudii |
Proteus mirabilis |
| Enterobacter aerogenes |
Proteus vulgaris |
| Enterobacter clocae |
Providencia spp. |
| Escherichia coli |
Peudomonas aeruginosa |
| Haemophilius influenzae |
Pseudomonas fluorescens |
| Klebsiella pneumoniae |
Serratia marcescens |
| Klebsiella oxytoca |
Shigella spp. |
| Moraxella catarrhalis |
|
The following microorganisms show varying degrees of susceptibility to
ciprofloxacin:
Burkholderia cepacia, Campylobacter spp.,
Enterococcus
faecalis, Morganella morganii, Nesseria gonorrhoeae, Proteus mirabilis,
Pseudomonas aeruginosa, Pseudomonas fluorescens, Serratia marcescens.
The
following microorganisms are considered inherent / resistant to
ciprofloxacin:
Staphylococcus aureus (methicillin-resistant) and
Stenotrophomonas maltophilia.
Ciprofloxacin has been shown to be active against Bacillus anthracis both
in
vitro and by use of serum levels as a surrogate marker.
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3
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