Anti-infectives part 2 Flashcards
Which antibiotics demonstrate gram + sensitivity?
gramicidin, macrolides, vancomycin, bacitracin
what are 2 types of concentration dependent antibiotics?
aminoglycosides and fluoroquinolones
which 3 antibiotics should you not take with food?
“PAT an empty stomach” = penicillins, azithromycin and tetracyclines
would you give cephalosporins to a hemophilic patient?
no - cephalosporins cause vitamin K deficiency which is important for blood clotting
what is the IV drug of choice for MRSA, MRSE and bacterial endophthalmitis?
Vancomycin
what drug combo is used most commonly for pediatric ocular infections?
Polymyxin B + Trimethoprim
Aminoglycosides and tetracyclines act by binding to and inhibiting which ribosomal subunit?
30S
which drugs inhibit 50S ribosomal subunit?
macrolides and chloramphenicol
which aminoglycoside has a class B pregnancy rating?
Tobramycin (tobradex)
Pseudotumor cerebri is associated with which specific aminoglycoside?
gentamicin
which are the most common aminoglycosides that can cause a type 4 delayed hypersensitivity reaction?
all 3 = gentamicin, tobramycin, neomycin
Neomycin is most common
which tetracycline do we use most commonly to treat eyelid/meibomian gland conditions?
doxycycline (except in children = AzaSite)
*chlamydia, meibomianitis/meibomian gland stasis, acne rosacea
when prescribing a tetracycline, what types of food should they avoid eating?
dairy products (binds to divalent calcium which renders the antibiotic dysfunctional)
Fanconi’s syndrome is associated with which type of drugs?
tetracyclines
which macrolides would you consider one of the safest antibiotics?
erythromycin and azithromycin = pregnancy class B ratings
which macrolide is “ok” for pregnancy and infants?
azithromycin
what type of patients should you be cautious to in giving macrolides?
asthmatics = macrolides augment plasma levels of theophylline
why should you be cautious in giving chloramphenicol to newborns?
grey baby syndrome
is trimethoprim a sulfa drug?
no = folic acid inhibitor
do sulfa drugs work well in highly mucopurolent environments?
no = there is excessive PABA in discharge
which topical drug is 1st line of treatment for MRSA with 95% efficacy? what is 2nd?
trimethoprim
tobramycin
what folic acid inhibitor combo do you use to treat toxoplasmosis?
sulfadizine + Pyrimethamine
what is a common adverse reaction of trimethoprim?
TMP = treats marrow poorly
bone marrow suppression
your patient is allergic to BAK - but you need to treat their infection, which drug would you use?
moxifloxacin
which drug does not exhibit bacterial resistance?
besifolxacin with durasite = no systemic predecessor
tendinitis is an adverse reaction of which class of drugs?
fluoroquinolines
which ocular antibiotic is least resistant to gram + infections?
trimethoprim/polymyxin B and besifloxacin
which drugs are best for treating pseudomonas infections?
fluoroquinolones, aminoglycosides, polymyxin B
what is the 1st line of therapy for recurrent HSV1 and HSV2 keratitis?
trifluridine (viroptic) - may be combined with oral acyclovir therapy
your patient presents with acute herpetic keratitis (dendritic ulcers) - what drug will you prescribe?
Ganciclovir (Zirgan) - caution with cross-resistance with acyclovir
what type of ocular involvement would you see in a patient with fungi?
cornea, conjunctiva, lens, CB, vitreous body and uvea
what percentage of acanthamoeba keratitis cases are associated with CL wear > trauma?
85-95%
what is the life-cycle of acanthamoeba?
trophozoites cysts
which organism accounts for 50% of ocular infections (is it gram + or -)?
staphylococcus - gram +
polymyxin B attacks what part of the cell and what gram type is it for?
cell membrane - gram negative
which class of antibiotics attack the cell’s DNA production?
fluoroquinolones
which drug class irreversibly inhibits protein synthesis?
aminoglycosides
all tetracyclines should not be taken with food except which one?
doxycycline
which drug class and specific drugs can treat acne rosacea?
tetacyclines (doxycycline and minocycline)
what is the only tetracycline that you should take if you have malfunctioning kidneys?
Doxycycline
which gram + antibiotic is the only one that permits QD dosing?
AzaSite (azithromycin)
which fluoroquinolone can cause white corneal precipitates?
ciprofloxacin
which antifungals do not cause hepatotoxicity?
echinocandins (metabolized by liver enzymes) and amphotericin B (but toxic to kidneys)
chronic antibiotic therapy can pre-dispose patients to what type of infection?
fungal
name the fungi that may attack the eye and what can make it worse?
canidida, crytococcus, aspergillus, fusarium, and curvularia
CL’s, steriods, trauma, immunocompromise
