Anti-Infective Medications Used in Eyecare Part 1 Flashcards
Exam 1
What types of drugs inhibit cell wall synthesis?
Penicillins (PCN)
Cephalosporin
Bacitracin
Vancomycin
What types of drugs disrupt cell membranes?
Polymyxin B
Gramicidin
What types of drugs inhibit protein synthesis?
Aminoglycosides
Tetracyclines
Macrolides
Chloramphenicol
What drugs inhibit folate synthesis?
Sulfonamides
Trimethoprim
What drugs inhibit DNA gyrase and topoisomerase?
Fluoroquinolones
You should never taper a(n) __________.
antibiotic
What is a possible side effect of taking oral antibiotics?
Decreased effectiveness of birth control pills, rifampin has the most impact
What percent of ocular infections are caused by G+ bacteria? G-?
G+ 70%
G- 30%
What are the most common G+ organisms that cause ocular infections?
S. aureus
S. epidermidis
S. pneumoniae
Lesser extent: Listeria
What are the most common G- organisms that cause ocular infections?
Moraxella
H. influenza
P. aeruginosa
Is bacterial conjunctivitis more common in children or adults in the US?
Children
23% in 0-2 years of age
28% in 3-19 years of age
What are the most common pathogens in adults?
S. aureus G+
H influenzae G-
S. pneumoniae G+
Moraxella catarrhalis G-
What are the most common pathogens in kids?
H. influenza G-
S. pneuomiae G+
S. aureus G+
Moraxella catarrhalis G-
What special population is associated with MRSA?
Nursing homes/group living setting
What special population is associated with N. gonorrhoeae and Chlamydia?
Sexually active
What percent of patients with bacterial keratitis are contact lens wearers?
19-42%
What are the most common pathogens related to CL bacterial keratitis?
S. aureus G+
Pseudomonas a. G-
What is the worst-case scenario for corneal infection?
Corneal perforation
What are the organisms that can penetrate an intact cornea?
Acanthamoeba Shigella Listeria G+ N. gonorrhoeae G- Corynebacteria Haemophilus G-
AS LUNCH
What is the most common pathogen that causes a hordeolum?
S. aureus G+
What are the most common pathogens that cause preseptal cellulitis? (5)
S. aureus G+ S. epidermidis G+ S. pneumoniae G+ H. influenza G- Anaerobes
What are the most common pathogens that cause acute dacryocystitis?
S. aureus G+
Pseudomonas G-
What are the most common pathogens that cause chronic dacryocystitis?
Coagulase-negative staphylococci
S. aureus G+
S. pneumoniae G+
What is the difference between bacteriocidal and bacteriostatic drugs?
Bacteriocidal drugs kill microbes
Bacteriostatic drugs prevent their growth and the immune system is responsible for ridding the body of the pathogen
What is the MOA of penicillins?
Inhibit cell wall synthesis by targeting peptidoglycan
Are penicillins bacteriocidal or bacteriostatic?
Bacteriocidal meaning it kills bacteria
What is the main cause of penicillin resistance?
Penicillinases: Enzymes in bacteria that inactivate penicillin
What are the three penicillins we need to know?
Amoxicillin
Augmentin
Dicloxacillin
What is the spectrum of amoxicillin? Is amoxicillin resistant to penicillinase
Mostly G+ with some G-
Amoxicillin is NOT resistant to penicillinase
What is the spectrum of augmentin? Is augmentin resistant to penicillinase?
Augmentin = amoxicilin + clavulonic acid
Clavulonic acid inhibits penicillinase
What is the drug of choice for pediatric soft tissue disease?
Mostly G+ with some G-
Augmentin
Soft tissue diseases like preseptal or hordeolum
What is the spectrum of dicloxacillin? Is dicloxacillin resistant to penicillinase?
Mostly G+ with some G- (Not as good as amoxicillin for G-)
Resistant to penicillinase
What are some adverse effects of penicillins?
Hypersensitivity, the second reaction is often worse than the first.
Cross allergenicity between different penicillins
GI disturbance
Which penicillin has an association with Stevens-Johnson Syndrome?
Amoxicillin
What other drug do penicillins have a cross-sensitivity with that should be considered when a patient has a penicillin allergy?
Cephalosporins have 1-10% cross-sensitivity, avoid if a patient has anaphylaxis with penicillins.
What is the MOA of cephalosporins?
Similar to penicillins, cephalosporins inhibit cell wall synthesis
Are cephalosporins bacteriostatic or bacteriocidal?
Bacteriocidal
How do cephalosporins vary between generations?
Newer generations have less cross-sensitivity than older generations
Newer generations have less resistance
Newer generations have a broader spectrum
Gen 1: G+
Gen 2: G+ and some G-
Gen 3: G+ and G-
What are the cephalosporins we need to know?
Keflex (Cephalexin)
Rocephin
What is Keflex? What is the spectrum of coverage for Keflex?
Keflex is a 1st generation cephalosporin that is effective on G+ organisms like staph and strep
What is Keflex a great treatment option for?
Adult soft tissue disease like a hordeolum, preseptal, dacryocystitis, and dacryoadenitis