24. Topical Antibiotics & Clinical Use Flashcards
Why do topical eye drops almost always overflow?
Tear film contains 30μL of tears, whereas a drop in eye drops tend to have around 50μL, therefore it will overflow.
Topical eye drops cannot maintain high bioavailability in a short amount of time due to quick drainage, what other methods can we use to increase contact time?
• Use ointments
• Slow down drainage by doing punctal occlusion
What should be tapered and what should not be?
Steroids should be tapered, whereas antibiotics should not.
Which condition is pulse dose commonly used on? How is it done?
Moderate anterior uveitis.
Start off intensively with one drop every 10 minutes for 4 hours then a drop every 2 hours.
If there is no ...
, the eye does not have ...
infection. If there is, there will be ..., ... discharge
. If there is ...
conjunctival injection, the eye is ...
, because ...
will not cause just part of the eye to be red. Unless the patient gives ...
or unless there is a true threat to the ...
, the use of ...
is of no clinical value.
If there is no discharge
, the eye does not have bacterial
infection. If there is, there will be greenish, mucopurulent discharge
. If there is sectorial
conjunctival injection, the eye is not infected by bacteria
, because bacteria
will not cause just part of the eye to be red. Unless the patient gives a history of mucopurulent discharge
or unless there is a true threat to the cornea
, the use of topical antibiotics
is of no clinical value.
What are the 3 common groups of topical antibacterials used in ocular diseases?
- *Chloramphenicol
- Fluoroquinolone (*ciprofloxacin, *ofloxacin)
- Aminoglycosides (gentamicin, *tobramycin, neomycin, framycetin)”
What are the 3 common topical compounded antibacterials used in ocular diseases?
• Gramicidin
• Bacitracin
• Polymixin
What are the 5 common oral antibacterials used in ocular diseases?
• Tetracyclines (doxycycline)
• Macrolides (azithromycin, erthromycin)
• Penicillins (flucloxacillin, amoxycillin)
• Cephalosporins (cefazolin, ceftriaxone)
• Glycopeptides (vancomycin)
There are 4 different topical antibacterial formulations in Australia:
* Multi-use (...
) eye drops: gentamicin, ...
, framycetin, ...
, ...
, ...
* Single-use ...
eye drops (...
): gentamicin, ...
* Eye ...
: tobramycin, framycetin, ...
* ...
eye drops: gentamicin/ tobramycin 1.3% + ... %
There are 4 different topical antibacterial formulations in Australia:
* Multi-use (preserved
) eye drops: gentamicin, tobramycin
, framycetin, ciprofloxacin
, ofloxacin
, chloramphenicol
* Single-use non-preserved
eye drops (Minims
): gentamicin, chloramphenicol
* Eye ointments
: tobramycin, framycetin, chloramphenicol
* Fortified
eye drops: gentamicin/ tobramycin 1.3% + cephazolin 5%
Compare the expense, sterility, application and properties of minims and bottle topical antibiotics.
Minims are more expensive, more sterile and non-preserved;
Bottle is generally less expensive, has questionable sterility since it is used over multiple patients and contains various preservatives.
Both are used the same way in terms of application.
Chloramphenicol is a ... covering both ...
, however it does not work against ...
. It has good ...
and is ...
. It is ...
rather than ...
, meaning that it doesn’t kill the bacteria. It is usually the ...
, unless the px’s issue correlates with ...
use. This is commonly used for ...
, ...
after surgery, and ...
. There are associations between use of ...
chloramphenicol and ...
, however there are no associations with ...
chloramphenicol.
Chloramphenicol is a broad spectrum antibacterial covering both G+ and G-
, however it does not work against pseudomonas
. It has good ocular penetration
and is well tolerated
. It is bacteriostatic
rather than bactericidal
, meaning that it doesn’t kill the bacteria. It is usually the first choice topical antibiotic
, unless the px’s issue correlates with contact lens
use. This is commonly used for conjunctival bacterial infection
, prophylaxis
after surgery, and superficial trauma
. There are associations between use of oral
chloramphenicol and aplastic anaemia
, however there are no associations with topical
chloramphenicol.
There are two types of fluoroquinolones: ...
and ...
. Both of these are ...
and is excellent against ... bacteria
, including ...
associated with contact lens wear, and ... bacteria
, including ` … and ….
… has better corneal penetration but higher rates of
… when used in high dosages.
… commmonly
… on … resulting in a
transient …, however this does not interfere with healing.
Fluoroquinolones are commonly used for
…,
… due to their
…,
…. Fluoroquinolones are used when there is
…. Some surgeons use this
off label for …`.
There are two types of fluoroquinolones: ofloxacin
and ciprofloxacin
. Both of these are bactericidal
and is excellent against gram negative bacteria
, including pseudomonas
associated with contact lens wear, and gram positive bacteria
, including staphylococcal
and streptococcal
. Ofloxacin
has better corneal penetration but higher rates of corneal perforation
when used in high dosages. Ciprofloxacin
commmonly precipitates on microbial keratitis ulcers
resulting in a ` transient white precipitate, however this does not interfere with healing. Fluoroquinolones are commonly used for
microbial keratitis,
CL related lesions due to their
maximum gram negative coverage,
severe conjunctivitis. Fluoroquinolones are used when there is
poor responses to chloramphenicol. Some surgeons use this
off label for post cataract surgery`.
Aminoglycosides includes ...
, ...
, and ...
. These are mainly active against ... bacteria
. They are commonly used for ...
, ....hypersensitivity reaction
, ` …. They maybe sometimes be used as
… after surgery. Aminoglycosides are available in
… and
…` form.
Aminoglycosides includes framycetin
, gentamicin
, and tobramycin
. These are mainly active against gram negative bacteria
. They are commonly used for ocular irritation
, type 4 delayed hypersensitivity reactions
, contact blepharodermatitis
. They maybe sometimes be used as prophylaxis
after surgery. Aminoglycosides are available in topical eye drop
and ointment
form.
Rank the causes of contact lens related microbial keratitis from most common to least common.
Pseudomonas aeruginosa> gram positive staphylococci > other gram negative > yeast & fungi / Acanthamoeba
Uses of topical anti-bacterial in pregnancy and breastfeeding:
* ...
- avoid use in ...
or ...
; but can be used in ...
* ...
- caution use in ...
but can be use in ...
and in ..
* ...
- safe to be used in ..., ... and in ...
* Topical antibiotics should be avoided in family history of ...
Uses of topical anti-bacterial in pregnancy and breastfeeding:
* Fluoroquinolones
- avoid use in pregnancy
or lactation
; but can be used in kids
* Aminoglycosides
- caution use in pregnancy
but can be use in lactation
and in kids
* Chloramphenicol
- safe to be used in pregnancy, lactation and in kids
* Topical antibiotics should be avoided in family history of blood discrasia