Exam One Drugs to Know and MOA Flashcards
what are some antivirals drugs
viroptic ( cat. C), Zirgan ( Cat C), Acyclovir ( Cat.B), Valacyclovir ( Cat B), Famciclovir ( Cat B), Betadine ( Cat C)- oral antivirals are B and topicals are C
this drug inhibits DNA synthesis of the both the virus and the host ; inhibits thymidine synthetase ( topical)
1 % Trifluridine ( Viroptic)
what is the dosage for 1% Trifluridine ( Viroptic)
1 gt q.2.h x 7 days up to 9 gtt/d ; then q.4-6.h
whats 1% Trifluridine ( Viroptic ) indicated for
recurrent HSV keratitis and stromal HSV
what are SE of 1% Trifluridine ( Viroptic )
SPK or Superficial puntate epithelial erosions; conj edema; delayed wound healing
this drug selectively targets virus infected cells ; its a prodrug; effective as Viroptic with less SE ( topical )
Ganciclovir gel ( Zirgan)
whats the indication for Ganciclovir ( Zirgan)?
HSV dendritic keratitis
whats the dosage for Gangiclovir gel ( ZIrgan)
1 gt in affected eye 5 times per day until the ulcer heals; then 1 drop tid x 7 days
what are the topical drugs for treating viral infections
1% Trifluridine ( Viroptic) and Ganciclovir Gel ( Zirgan)
what are the orals for treating viral infections
acyclovir, Valacyclovir, and famcyclovir
this drug is phosphorylated to active compound by HSV thymidine kinase ; specific for viral infected cells. does not affect host
acyclovir ( oral): indicated for HSV dendritic keratitis
what is the antiviral MOA
all are placebo in nature until conversion to active form by viruses -> viral thymidine kinase activates antivirals via process of phosphorylation-> antivirals get spliced into viral DNA/RNA which screws up replication cycle -> viral death ensues
this drug is used for the acute tx of HSV keratitis; also inhibits recurrent HSV epithelial keratitis and genital herpes ( maintenance dose )
Acyclovir ( Zovirax) - ointment and oral available
what is the dosage for acyclovir ( Zovirax ) for acute HSV keratitis
400 mg q.4.h. to 5xd for 7-14 days - use this if pt allergic to viroptic
whats the maintenance dose of acyclovir ( Zovirax) for recurrent HSV epithelial keratitis
400 mg b.i.d x 12 mos .
what are the preps for Acyclovir
oral tabs ( 200,400, and 800 mg tabs) , IV , and non ophth. ung
this drug is the prodrug to acyclovir ; has greater GI absorption
Valacyclovir ( Valtrex)
whats the dosage of Valacyclovir ( Valtrex)
one gm tid . VZV and 500 mg tid HSV ( caps are 500mg and 1000 mg)
whats the maintenance dose of valacyclovir
1 gm qd x 1 year
this drug is indicated for HSV: genital and ophthalmic ; it inhibits viral DNA ; pro drug of penciclovir
Famciclovir ( Famvir)
whats the dosage of Famciclovir
250 mg tid x 7 days ; for suppression of recurrent HSV 250 mg b.i.d. x 1 year
what are the topical options for acute HSV dendritic keratitis
Viroptic or Zirgan
What are the oral options for acute HSV dendritic keratitis
acyclovir, Valacyclovir, and famcyclovir
which drug is mainly used for Herpes / VZO ( recurrent ) HZO- shingles
Acyclovir : Zovirax
what is the dosage and tx for recurrent HZO with acyclovir ( Zovirax)
initiate within 72 hrs; 800 mg 5x/d x 7 days
this drug is used for acute Herpes Zoster Opththalmicus and Shingles ; does is 500 mg tid x 7 days
Famciclovir : Famvir
this drug is used for recurrent orolabial herpes
penciclovir aka denavir
how does the dosage changer for HSV versus VZV treatment
Simplex: Acyclovir is 400 mg five x day for 7-10 days, Valacyclovir is 500 mg TID for 7-10 days, and Famciclovir is 250 mg tid x 7-10 days
Herpes: Acyclovir 800 mg 5x day for 7-10 days, Valacyclovi r is 1000 mg tid for 7-10 days , and Famciclovir us 500 mg tid for 7-10 days
what is a negative caveat of oral antivirals
all are excreted via the kidney so CI in pts with kidney failure and or on dialysis
this is a vaccine used to prevent Shingles ( Herpes Zoster), its a live attenuated vaccine and it boosts VZV specific immunity
VZV: Zostavax vaccine
with the shingles prevention study, what % had a decreased total risk
51% ( with the ZEST trial, 70% decreased risk)- recommend vaccine for anyone over 50 ; cate. C drug
this drug is used “ off label” for EKC aka adenovirus; FDA cat. C ; use 1 gtt proparacaine and NSAID; 4-6 gtts of this drug, then after a min saline rinse ; then instill 2 gtts NSAID in office and Rx steroid gt qid x 4 days
betadine :povidone - iodine ( betadine decreased the viral load and the steroid is used to take care of the inflammation)
also can use Ganciclovir Gel: Zirgan
this is a new combo drug under study to treat adenovirus
dexamethasone 0.1% and betadine 0.4%
what are some antiviral agents for cytomegalovirus
ganciclovir, zidovudine, foscarnet, and Cidofovir ( all are injected or taken orally)
these are the polyenes antifungal agents; they increase cell membrane permeability and are fungicidal
natamycin, nystatin , and amphotericin B
this antifungal agent impairs DNA synthesis ; fungistatic
flucytosine
these are azoles; they block ergosterol synthesis -> increase cell membrane permeability ; fungistatic first and fungicidal later
miconazole, ketoconazole, viroconazole, itraconazole
this is the only FDA approved topical antifungal ; has a board spectrum against candida, aspergillus, cephalosporin, fusarium, and penicillium
Natamycin ( Natacyn 5%) susp.
these drugs disrupt the cytoplasm of the cellular membranes of acanthamoebas;
diamidines and biguanides
these are used in the tx of acanthamoebas: types include Brolene and Demodine
Diamidines
these are used in the tx of acanthamoeba; types include PHMB and chlorhexadine
biguanides
these drugs target the cell wall and break down the peptidoglycan
bacitracin and vancomycin
these drugs target the cell wall and break down transpeptidase enzyme
PCN and cephalosporins
this drug is only available in ung; most commonly rx for blepharitis
bacitracin ( fights gram +)
which drugs form polysporin
(+) bacitracin and - polymixin B
which drugs form neosporin
+- polysporin and +- neomysin
this drug is mainly given as IV for MRSA and endophthalmitis; SE = ototoxicity, nephrotoxicity, and red man syndrome
vancomycin
this drug can be compounded for ophthalmic use ( topical or subconj injection)
vancomycin ( used when other Ab are not effective esp in corneal ulcer)
which types of drugs are standard therapy for bacterial keratitis
fortified Ab ( ie gentamycin, tobramycin, amikacin, vancomycin, and cephalozin )
which PCN affect gram pos bacteria
natural PCN
which PCN affect gram +/-
amino PCN
what is a gen 1 cephalosporin
gen 1- cephalexin
what is a gen 2 cephalosporin
cefuroxime
what Is a gen 3 cephalosporin
ceftriaxone
what happens with bacteria that contain beta lactamase
the beta lactam Ab contains the beta lactam ring- this becomes inactivated by beta lactamase and penicillinase resistant bacteria
SE pf PCN?
type I and IV hypersensitivity, nausea and vomiting, decreased effectiveness of Birth control pills
what are natural PCNs mainly used for
gram +, syphilis, gonorrhea
what are some amino PCNs
ampicillin- oral , amoxicillin - oral suspension , augmentin
what makes up augmentin
amoxicillin + clavulanic acid ( clavulanic acid is a penicillinase inhibitor)
these drugs are indicated for dacryoadenitis, dacryocystitis, Preseptal cellulitis, internal hordeolum
amino PCNs
how do we dose amino PCNs
moderate infection ( 250 mg PO tid or 500 mg PO bid) severe infection ( 500 mg PO tid , 875 mg PO bid )
T or F: if pt allergic to PCN don not give cephalosporin gen 1
T
this is a gen 1 cephalosporin that is used for Preseptal cellulitis, internal hordeolum
cephalexin ( Keflex) - oral 250-500 mg bid-tid x 7-10 days
what is mainly rx in hospital setting and is used in orbital cellulitis
cephalosporin gen 3,. ceftriaxone
these drugs disrupt folic acid production in bacteria
sulfanomides and trimethoprim
these drugs disrupt the DNA gyrase and Topoisomerase IV in bacteria
Gen 2 FLQ, Gen 3 FLQ, and Gen 4 FLQ
which drug is often used with pyrimethamine to tx toxoplasmosis
sulfadiazine
which drug is often used in combo with trimethoprim
sulfamethoxazole : Bactrim = sulfamethoxazole + trimethoprim
what is the DOC for MRSA
trimethoprim
SE of sulfonamides
oral: nephrotoxicity, kernicterus, myopia
topical : stevens johnsons syndrome, drug allergies . CI in pregnancy
T or F: Trimethoprim is not effective against Pseudomonas
T
this drug is the DOC for MRSA in Ocular Trust Study ; available as oral ; SE = bone marrow suppression; CI in pregnancy ; available as ung in combo with Polymixin B ( polytrim)
trimethoprim