Infectious Disease 1: Background & Antibiotics by Drug Class

Common skin/soft tissue pathogens

Staphylococcus aureus and Streptococcus pyogenes, staphyloccus epidermis

Common lower respiratory pathogens (community)

strep pneumo, haemophilus influenzae, atypicals (legionella, mycoplasma, chlamydophilia)

Common lower respiratory pathogens (hospital)

staph aureus (including MRSA), Pseudomonas aerug, acinetobacter baumannii, ESBL, MDR, strep pneumo

common mouth pathogens

viridans group streptococci, peptostreptococci

common CNS/meningitis pathogens

strep pneumo, neisseria meningitidis, haemophhils influenzae, group B strpe, E.coli (young) listeria (young +old)

common upper respiratory pathogens)

strep pyogenes, strep pneumo, haemophils influenzae, moraxella catarrhalis

common heart/endocarditis pathogens

staphyloccus aureus (including MRSA), stap epidermis, strep, enterococci

common urinary tract pathogens

e.coli, proteus, klebsiells, staph saprophytics, enterococci

common intra-abdominal pathogens

enterococci, streptococci, bacterioides

common bone/joint pathogens

staph aures, staph epidermidis, strep, neisseria gonorrhoeae

Gram positive bacteria stain ____ in color from _____ stain due to their ______

they stain purple/bluish

from crystal violet stain

due to thick cell wall

Gram negative bacteria stain ____ in color from _____ stain due to their ______

Stain pink/reddish

from safranin counterstain

due to thin cell wall

Atypical organisms stain _______ due to _____

do not stain well, not having a cell wall

Pseudomonas Aeruginosa is a gram _____

negative

Moraxella Catarrhalis is a gram ____

negative

Staphylococcus aureus is a gram _____

positive

Strep pneumoniae is a gram _____

positive

Haemophilus influenzae is a gram _____

negative

Numbers on an antibiogram represent

% susceptibility of each organism to listed drug

Example of synergy in antibiotics

aminoglycosides and beta lactams treating a gram-negative positive (endocarditis)

beta lactam allows Ag to reach ribosome, allowing a lower dose of Ag to be used, and clears infection quicker

Common Resistant Strong pathogens

Kill Each and Every Strong Pathogen

K: Kelbisella Pneum. (ESBLE CRE)

E: Escherischia Coli (ESBL, CRE)

A: Acinetobacter baumannii

E: Entercoccus facecalis, Enteroc. faceium (VRE)

S: Stap aureus (MRSA)

P: Pseudomonas aeruginosa (PA)

Vancomycin being too large to penetrate the bacterial cell wall of E. coli is an example of ____ resistance

intrinsic resistance: resistance is natural to the organism

When vancomycin eliminates susceptible entercocci, VRE can become predominant. This is an example of ____

selection pressure

bacterial DNA containind resistant genes can be transferred b/w species or picked up from dead bacterial fragments in environment. This is an example of _____ resistance

acquired

Bacteria that produce beta-lactamases break down beta-lactams before they can bind to their site of activity. This is an example of ______

enzyme inactivation

treatment for ESBL

carbapenems or newer cephalosporins/beta-lactamase inhibitors

CRE (MDR) : what they are and their treatment

G- organisms that product carbapenemases (can break down penicillins, cephs, and carbapenems)

require treatment with a combo of polymyxins (high tox). newer costly drugs like ceftazidime, avibactam.

True/False: all antibiotics have a warning for C dif.

True

Which antibiotics carry the highest risk of C. Dif

clindamycin

braod-spectrum penicillins and cephalosporins, quinolones, carbapenems

Antibiotic with a boxed warning for c dif

clindamycin

Most cell wall and cell membrane inhibitors, DNA/RNA inhibitors, and aminoglycosides are _____ while most protein and folic acid synthesis inhibitors are _____

bactericidal

bacteriostatic

Medications that are lipophilic have a _____ volume of distribution and ______ tissue penetration

large Vd, excellent tissue penetration

Medications that are hydrophilic have a _____ volume of distribution and ______ tissue penetration

small Vd, poor tissue penetration

Lipophilic agents are excreted via ______, there is concern for _____

hepatic metabolism, Drug interactions

Hydrophilic agents are excreted via ______, there is concern for _____

renal, accumulation if not dose adjusted

Hydrophilic drugs have ______ bioavailable making their ratio of IV:PO ______

poor-moderate bioavailiability

often not 1:1 ratio

lipophilic drugs have ______ bioavailable making their ratio of IV:PO ______

excellent bioavailability

1:1 ratio

hydrophilic drugs have ____ clearance in sepsis, so ________

increased clearance,

so consider loading dose and aggressive dosing

lipophilic drugs have ____ clearance in sepsis, so ________

no change in clearance

dose adjustments are generally not needed in sepsis

Hydrophilic agents include

beta-lactams, aminoglycosides, vancomycin, daptomycin, polymyxin

lipophilic agents

Quinolones

Macrolides

Rifampin

Linezolid

Tetracyclines

_______ Agents can achieve intracellular concentrations, making them active against atypical organisms

lipophilic

Aminoglycosides display ______-dependent killing and can be dose _______

concentration-dependent killing

dose them less frequently and in higher doses to maximize concentration above MIC

(High peak low trough, large dose long interval)

Beta lactams display ______-dependent killing and should be dosed _____

time-dependent killing

dose them more frequently, or each dose can be administered for a longer duration to maximize time above MIC (continuous infusion for beta lactam for example to reduce hospital stay)

Quinolones exhibit ___ dependent killing

concentration

daptomycin exhibits _____ dependent killing

concentration

Vancomycin exhibits ____-dependent killing.

exposure-dependent killing (AUC)

macrolides, tetracyclines, and polymyxins exhibit ____dependent killing

exposure

Beta lactam MOA

inhibit bacterial cell wall synthesis by binding to penicillin binding proteins (PBPs) to prevent final step of peptidoglycan synthesis in bacterial cell wall

Beta lactamase inhibitors include

clavulanic acid, sulbactam, tazobactam

Coverage of the different types of penicillins

Natural

antistaphylococcal

aminopenicillins

aminopenicillins + beta lactamases

extended spectrum penicillins + beta lactamases

Coverage of the different types of penicillins

Natural: Strep and entercoccal

antistaphylococcal: Stap and strep

aminopenicillins: strep, enterococcal,

aminopenicillins + beta lactamases: strep, enterococcal, staph, HNPEK, anaerobes

extended spectrum penicillins + beta lactamases: all above + CAPES + PA

Name the natural pencillins

penicillin G benzathine, penicillin VK

Route of administration for Penicillin G benzathine

IM, IV is fatal

Name Antistaphylococcal penicillins

Cloxacillin (PO)

Dicloxacillin (PO)

Nafcillin (IV)

Oxacillin (IV)

**Oxa, Cloxa, Dicloxa, and Naf**

Name the aminopenicillins

Ampicillin (IV, PO)

Amoxicillin (PO)

Name extended spectrum penicillins

Ticarcillin

Piperacillin (piperacillin/tazobactam: Zosyn)

This penicillin must only be diluted in NS

IV ampicillin as well as ampicillin/sulbactam

These penicillins do not require renal adjustment

antistaphylococcal penicillins

Common side effects with penicillins

anaphylaxis, seizures w/ accumulations if not dose adjusted for renal dysfunction, GI

Exceptions to the interaction that all BLs increase warfarin effects

nafcillin and dicloxacillin

Exception to never picking a BL in a BL/PCN allergy

Pregnant patient has syphilus, can desenstizie

Probenecid interaction

increases BLs

Other interactions with BLs

MTX is increased

Only penicillin active against Pseudomonas

Zosyn

FL treatment for otitis media

amoxicillin or augmentin

PCN used FL for strep and mild non abscess skin infections

pen VK

FL for bacterial sinusitis PCN

Augmentin

PCN that is a vesicant and should be administered through a central line?

How to treat its extravasation?

nafcillin

cold packs, hylauronides

PCN that is often administered as inpatient extended infusion to maximize time > mic

zosyn

As cephalosporin generation increases, their activity against ____ increases generally

Gram negatives

cephalosporins generally lack activity against ______

enterococcus and atypicals

Cephalosporins in first generation

cefazolin, cephalexin

coverage of first generation cephalosporins

strep, staph, G- rods, PEK (proteus, e. coli, klebs)

2nd Gen. cephalosporins

Cefuroxime and cefotetan, cefoxitin

Coverage 2nd generation cephalosporins

cefuroxime: staph, S pneumo, HNPEK

Cefotetan, cefoxitin: G- anaergoves, B. fragilis

3rd generation cephalosporins

ceftriaxone, cefotaxime, caftazidime

3rd gen cephalosporin coverage

ceftriaxone and cefotaxime: Strep, viridans group strep, staph, G+ anaergobes, HNPEK

Ceftazidime: no G+ activity, covers PA

This cephalosporin has no G+ activity but covers Pseudomonas

ceftazidime

fourth generation cephalosporins

Cefepime (Maxipime)

fourth gen. cephalosporin coverage

Broad g- HNPEK, CAPES, PA, G+ like ceftriaxone

Fifth generation cephalosporin

Ceftaroline

Ceftaroline brand name

Teflaro

Fifth generation cephalosporine coverage

broad G+, only BL that covers MRSA

Cephalosporine that covers MRSA

ceftaroline

Ceftriaxone warnings and considerations

kernicterus: warning in neonates <28 days

Warning in use with Ca-containing products IV: precipitates

Cephalexin dosing

250-500 mg q6-12h

This cephalexin causes a disulfiram-like reaction with alcohol

cefotetan

This generation of cephalosporins has the highest risk of cross-reactivity with PCNs

first gen.

This cephalosprorin doesn't require renal adjustment

ceftriaxone

Cephalosporin drug interactions

acid suppression medications and cefuroxime and cefpodoxime

-OXIME and acid

Clostridium difficile is a _____ organism

Gram positive

Exception to never choosing a cephalosporin in PCN allergy

pediatric with acute otitis media and mild PCN allergy

Common uses of cephalexin

skin infections, strep throat

common uses of cefuroxime

acute otitis media, CAP

common uses of cefdinir

acute otitis media

common uses of cefazolin

surgical prophylaxis

common uses of cefotetan and cefoxitin

GI procedure surgical prophylaxis

common uses of ceftriaxone and cefotaxime

CAP, meningitis, SBP, pyelonephritis

common uses of ceftaroline

CAP, SSTI

This antibiotic class increases the risk of seizures/lower the seizure threshold and this should be considered in patients with a seizure history or on an anti-epileptic drug

carbapenems: lower the seizure threshold