AntibioticsSH2 Flashcards
Penicillins
Inhibit cell wall ( wont work on mycoplasma)
Has 5 member ring
If probenecid used ( prolongs PCN serum level)
Spectrum of activity :
Strep , peptostreptococci, Treponema pallidum ( syphilis )
Use :
Pharyngitis, rheumatic fever, syphilis, dental prophylaxis / infection
Metabolized and excreted by kidney
Preg B
Benzathine PCN ( Bicillin L-A) vs Bicillin C-R
Bicillin L-A is Benzathine PCN vs Bicillin C-R is Benzathine PCN plus procaine PCN
B L-A: Group 1 strep : 1.2 million units IM single dose ( last in patients system 2 to 4 weeks so thats why single dose)
Rheumatic fever:
Syphilis 2.4 million units IM single dose
-3° syphilis: IM q week x 3 doses
-not for neurosyphilis ( IV for that )
For Bicillin C-R not FDA approved for syphilis.
B C-R: scarlet fever / group A strep
Penicillin G
IV formulation
NEUROSYPHILIS
Penumcoccal pneumonia, meningitis, Neurosyphilis, Anthrax
PCN VK
Pen-Vee K, Veetids
Po formulation
Take on on an empty stomach ( 1 hour before or 2 hours after a meal. )
Refrigerate soln.
If PCN allergy no ampicillin, amoxicillin or PCN
Decrease dose by 1/2 if CrCl <10
Pencillinase resistant PCNs
CONDM
cloxacillin- empty stomach - not available in US.
•Oxacillin - hepatoxicity : if dose > 12 g qd LFTs- IV
•Nafcillin - MSSA . Does not need to dose adjust in renal -IV ( this does not go through kidneys) ***** eliminated primarily by hepatic
•Dicloxacillin-empty stomach PO Route
Methicillin- no longer manufactured
AminoPCNs
Ampicillin, amoxicillin
Amp: empty stomach
rash diarrhea
Streptococci, enterococci, Listeria
Drug of choice for enterococcus ifx. Reality is resistance.
Reduce if CrCl < 10 ml/min -dose adjust
Recall nafcillin no dose adjust in renal
Amoxicillin
Strep, otitis media, dental prophylaxis
For kids 80-90 mg/kg/day ( 1st line for OM ). Use 90. This is a daily dose.
1.75 g/day once child reaches 20 kg.
3 g/day of amoxicillin in kids over 33 kg
4 g/day in kids over 44 kg for serious infections
Dental prophylaxis: 2 g ( 50mg/kg) 1 hour prior
Oral susp : 14 days room temp or refrigerator
Infant drops: amox 50 mg/ml
Endocarditis prophylaxis for dental procedures
Amox 2 g for adults 30-60 mins before
Allergy
Clindamycin 600 mg or
Azithromycin 500 mg
Clarithromycin 500 mg
Prophylaxis For who?
Valve replacement, congenital heart defects
( mitral valve prolapse, regurgitation or rheumatic heart disease do not need prophylaxis abx)
Beta lactamase inhibitors
Sulbactam, Clavulanate, Tazobactam
Broaden beta lactam abx
Beta-lactam combo agents
• zosyn - piperacillin /tazobactam ( IV ) stable in D5W, NS
• ampicillin /sulbactam ( Unasyn ) IV NS
• Augmentin ( amox/clav) PO refrigerate
Zosyn and timentin are anti psedomonal
Bet lactam combo spectrum: staph, enterococcus, streptococcus, B. fragilis, H influenza, M catarrhalis, Pseudomonas ( zosyn & timentin only )
Unasyn
Augmentin
Ampicillin sulbactam
Best mixed in NS
Amox/clav Augmentin
Can’t double of on lower to make higher strength. Bc clavulante component.
Refrigerate susp
Augmentin XR dont use w/CrCl <30
PCN is the only appropriate tx for syphilis during pregnancy so if pregnant and have an allergy your option is to desensitize PCN
T
Zosyn
Only IV
Great coverage ( including pseudomonas )
Covers intra abdominal ifx ( e. Coli , B fragilis )
Pelvic infections ( E. coli )
Nosocomial pneumonia : S auerus , actinobacter, H influenzae, klebsiella, and pseudomonas ( P aeruginosa should be treated in combination with an aminoglycoside )
Must dose adjust
CrCl> 40 start with 3.375 G IV q6 hr / nosocomial : 4.5 g IV q6h
If CrCl 20-40 dose adjust / if nosocomial stay or drop to 3.375
If <20 decrease dose again
Adverse effects
Allergy
PCN seizure
Augmentin : major diarrhea
Cephalosporins and PCN allergy
If PCN allergy, dont give cephalosporin on test question. But reality is cross reactivity is low. ( change of cross reactivity =0.1 %) on test assume severe PCN allergy where you definitely wouldn’t
Another one to avoid in pCN allergy is carbopenum
Multiple generations
First Gen Cephalosporin
covers mostly gram +, PEK organism ( Proteus , E. Coli & Klebsiella )
Cephalexin ( keflex )
-pnemonia, bone ifx,
-group A strep, skin infection( on skin we have staph or strep gram (+) ) , simple UTI
-not for otitis media
Cefazolin ( Ancef ) -surgical prophylaxis DOC ( IM/ IV )
Cefadroxil ( Duricef) -
All are preg B and RENAL
Usually 1st line for surgical prophylaxis
Second Gen Cephalexin
Gaining more gram ( - )
HENPEKS
H influenzae, Enterobacter aerogenes, Neisseria, Proteus mirabilis, E. coli, Klebsiella pneumonia, Strep Pneumoniae
know formulation. If pt is discharged we want them on same gen.
Cefaclor- PO ( not used much ) , Cefprozil ( Cefzil ) PO, Cefuroxime ( zinacef, ceftin ) - IM/IV/PO , Cefoxitin ( Mefoxin ) IV
Cefotetan - IM/IV
Cefoxitin & Cefotetan active against anaerobes ( b fragilis ) so can be used in intra-abdominal surgeries
2nd gen Cephs are 2nd line agent for otitis media. ( amoxicillin is 1st line)
CEFOTETAN has an NMTT ( N-methyltiotetrazole ) side chain: can increase risk of bleeding and can cause a disulfiram rxn
Cephs that cover pseudomonas
Pseudomonas aeruginosa
- Ceftazidime ( 3rd Gen )
- Cefepime ( 4th Gen ) ( IV/ IM )
- Ceftolozane/ tazobactam ( Zerbaxa a combo drug ) ( 5th gen )
Ceftriaxone ( Rocephin ) and Ceftazidime ( Fortaz ) are the two most commonly used IV preparations
T
Both are 3rd gen. Both hospital use. Not ORal
3rd gen oral Cephs
Cefdinir ( omnicef ) - give iron / vitamins / anatacids 2 hours apart. Dont refrigerate
Cefditoren ( spectracef ) - PO w/food. No antacids . Milk protein allergy ( recall dry powder inhalations for asthma are contraindicated )
Cefixime ( suprax ) -PO
Suspension at room temp or fridge 14 days • Ceftriaxone IM shot for gonorrhea first line. Cefixime 2nd line if they dont want a shot. ( “ please try to fix my gonorrhea “ ) Triaxone to fixime
Cefpodoxime ( PO ) / watch for antacids. With food. Susp in fridge.
Ceftibutin ( Cedax ) : PO stable for 14 d in fridge
IV / IM formualtions Ceph ( parenteral )
Ceftazidime ( fortaz, tazicef ) : IM /IV : covers pseudomonas
Combo: Avycaz : ceftazidime / avibactam : better coverage of resistant enterobacteriaceae, klebsiella and pseudomonas aeruginosa, but not acinetobacter
- IV over 2 H for complicated abdominal ifx, and UTI
Cefotaxime: ( Claforan ) - IM / IV
- Ceftriaxone ( rocephin )
Ceftriaxone
Meningitis and endocarditis
Ceftriaxone 250 mg IM + Azithromycin oral 1 gram : for gonorrhea
No renal adjustment
Dilute with 1% lidocaine for IM use/ cant be reconstituted with Ca containing products.
4th gen Ceph
IV / IM only
Cefepime ( maxipime ) : broad spectrum ( gram + /– ) and ANTI -Pseudomonal
- CNS tox : usually if high risk of renal impairment
Cefiderocol ( Fetroja ) : Trojan horse.
Covers: Acinetobacter, E. Coli, klebsiella, proteus mirabillis, PSEUDOMONAS , Enterobacter cloacae complex
- Pneumonia ( HAP & VAP )
-complicated UTI, including pyelonephritis
If CrCl ≥ 120 ml/min you can increase dose
5th Gen Ceph
• Ceftaroline ( Teflaro) - only Ceph that covers skin infection MRSA.
- we can use for CAP ( MSSA covered but not MRSA)
Hospital use only. 400 / 600 mg powder in vials.
Common SE: diarrhea , nausea , rash
• Zerbaxa ( combo : Ceftolozane / tazobactam ) - IV
-intra- abdominal infections when used in conjunction with metronidazole.
Dose adjust in RENAL
Carbapenems
PCN allergy: for purpose of test, you assume severe life threatening so dont give Carbapenems. ( in reality cross reactivity is low)
• Imipenum / cilastin ( Primaxin ) : cilastin prevents renal metabolism. Mix in NS. IV / IM q 6 - 8 Hr.
• Meropenem ( Merrem ) : NS or D5W
• Ertapenem ( Invanz ) : the only once daily Carbapenems. Q 24 hours. Best mixed in NS
•Doribax ( doripenem) :
Covers almost everything: gram +/– , anaerobes ,
Yes pseudomonas , acinetobacter ( but not ertapenem )
but NOT MRSA for all Carbapenems
DOC for infectious pancreatitis
Vabomere: meropenem + vaborbactam
SE: super-infection ( fungal pathogens ) bc killing off everything. PCN cross reactivity low but watch for severe PCN allergy
SEIZURES ( rate of seizures is a lot more than PCN seizure. )
DDI: Carbapenems can’t reduce valproic acid. Additive reaction: increasing seizure with ganciclovir.
Monobactam
Aztreonam
Covers gram ( - ) only.
Also covers pseudomonas.
Used for UTI
Moderately severe systemic infections.
Cystic fibrosis ( we worry about pseudomonas )
Who do we use this for ? Covering gram negative. Also can use it if patient can’t use aminoglycoside ( due to nephrotoxicity ) we can instead use aztreonam.
SE: rash
