Pharm III - Antibiotic Review

bacteriostatic

inhibits bacterial growth

bacteriocidal

kills bacteria

concentration dependent killing

rate and extent of bacterial kill increases with concentration of drug at the site of the infection

concentration independent killing

extent of bacterial kill is dependent on the amount of time the bacteria is exposed to a certain concentration of antibiotic

synergy

addition of two antibiotics together is more effective than the sum of each one alone

minimum inhibitory concentration (MIC)

estimate of sensitivity of a pathogen to a drug

gram positive

thick cell wall, stain dark purple/blue

gram negative

thin cell wall, stain pink/red

antibiogram

combines C&S from individual patients at one institution, helps aid in empiric antimicrobial decision making, used to monitor resistance patterns

penicillin G/VK

good GP coverage, resistance limits to group A and B strep

ampicillin, amoxicillin

aminopenicillins; enterococcus, slightly more GN coverage compared with PCN G/VK

nafcillin, oxacillin, dicloxacillin

antistaphylococcal penicillins, cover MSSA

piperacillin-tazobactam (Zosyn)

antipseudomonal penicillin, improved GP coverage, combined with beta-lactamase inhibitor

cefazolin, cephalexin

1st gen cephalosporins

cefuroxime, cefaclor

2nd gen cephalosporins

expanded GN coverage, some loss of GP coverage

cefotetan, cefoxitin

cephamycins, 2nd gen cephalosporins used for anaerobic coverage

ceftriaxone, cefdinir, ceftazidime

3rd gen cephalosporins

further expanded GN coverage, retains GP coverage from 1st gen

ceftazidime

3rd gen cephalosporin with PsA coverage

cefepime

4th gen cephalosporin

GP, GN, PsA coverage (no MRSA)

ceftaroline

5th gen cephalosporin

GP, GN, MRSA coverage (no PsA)

carbapenems

excellent GN, GP, and anaerobic coverage

NO atypical, MRSA, VRE coverage

doripenem

carbapenem that should not be used to treat pneumonia

imipenem

carbapenem with acinetobacter coverage

ertapenem

carbapenem without PsA and enterococcal coverage

aztreonam

monobactam; primarily used when beta-lactam allergy is present, great GN coverage (including PsA), NO GP coverage; ADEs: rash, GI intolerance

gentamicin, tobramycin, amikacin

aminoglycosides

concentration dependent killing, mainly GN coverage (including PsA), synergy dosing for GP pathogens; ADEs: nephrotoxicity, hearing loss

azithromycin, clarithromycin, erythromycin

macrolides

great atypical coverage, strep. pneumo, haemophilus, neisseria, moraxella; ADEs: GI upset, QTc prolongation, hepatotoxicity

fidaxomicin

macrolide used only for c. diff

levofloxacin, moxifloxacin

respiratory FQs

ciprofloxacin

non-respiratory FQ

delafloxacin

FQ only approved for SSTIs -- PsA and MRSA coverage

vancomycin

GP coverage, used for MRSA, oral is 1st line for c. diff, monitoring: nephrotoxicity, ototoxicity, myelosuppression, Red man syndrome

daptomycin

GP coverage, NOT used for pneumonia, includes VRE coverage, ADEs: myopathy, rhabdomyolysis

linezolid

similar to vancomycin, covers VRE like daptomycin; duration-limiting myelosuppression, peripheral/optic neuropathy, risk of serotonin syndrome with MAOi/SSRIs

doxycycline, minocycline, tetracycline

tetracyclines

cover anti-pneumococcal and CA-MRSA, impaired absorption with dairy products & aluminum, chelation with divalent cations, caution in children <8 (binds to calcium deposits in bone/teeth), induce photosensitivity

clindamycin

lincosamide antibiotic, covers most aerobic and anaerobic GP, BBW: c. diff; common uses: SSTIs, alternative to beta-lactams for dental procedures, suppress toxins/cytokines with strep pyogenes necrotizing fasciitis

sulfamethoxazole/trimethoprim (Bactrim)

sulfonamide

covers MSSA, MRSA, strep pneumo, some opportunistic pathogens; contraindications: sulfa allergy, end of pregnancy, breastfeeding, folate deficiency anemia, renal/hepatic disease; ADEs: photosensitivity, increased K, anemia, crystalluria

metronidazole (Flagyl)

covers anaerobes and protozoal pathogens; effective for BV, trich, giardiasis, amebiasis, c. diff; ADEs: metallic taste, HA, furry tongue, dark urine, rash/skin reactions, interaction with EtOH

rifaximin

structurally related to rifampin, covers E. coli, used for traveler's diarrhea, hepatic encephalopathy, IBS-D

cell wall inhibitor

MOA of beta lactams

penicillins, cephalosporins, carbapenems, monobactam

beta lactam drugs

cell wall inhibitor

MOA of vancomycin

protein synthesis inhibitor

MOA of aminoglycosides

protein synthesis inhibitor

MOA of macrolides

protein synthesis inhibitor

MOA of clindamycin

protein synthesis inhibitor

MOA of tetracyclines

protein synthesis inhibitor

MOA of linezolid

cell membrane inhibitor

MOA of daptomycin

DNA/RNA inhibitor

MOA of FQs

DNA/RNA inhibitor

MOA of metronidazole, rifaximin

folic acid synthesis inhibitor

MOA of sulfamethoxazole/trimethoprim (Bactrim)

ceftriaxone, azithromycin, doxycycline, linezolid, fidaxomicin, PO vancomycin

NO renal dosing adjustment

fluoroquinolones

cover variety of GN, GP, and atypical pathogens, ADEs: tendinitis, tendon rupture, QTc prolongation

strep pyogenes, strep pneumoniae

MC organisms causing upper respiratory infections

staphylococcus

MC organism causing endocarditis

enteric GNR, bacteroides

MC organisms causing intra-abdominal infections

staph aureus

MC organisms causing bone and joint infections

strep pneumoniae, neisseria meningitidis, haemophilus influenzae

MC organisms causing meningitis

strep pneumoniae

MC organism causing community acquired lower resp infections

staphylococcus, pseudomonas

MC organisms causing hospital acquired lower resp infections

e. coli

MC organism causing UTIs

staph aureus, strep pyogenes

MC organisms causing skin/soft tissue infections

augmentin

DOC for sinusitis

amoxicillin, augmentin

DOC for acute otitis media

pcn VK, amoxicillin

DOC for pharyngitis

vancomycin

DOC for endocarditis

zosyn or ertapenem

DOC for intra-abdominal infections

vancomycin + ceftriaxone

DOC for bone and joint infections

ceftriaxone + vancomycin

DOC for meningitis

amoxicillin or doxycycline or augmentin

DOC for community acquired lower resp infections

PsA coverage +/- vancomycin

DOC for healthcare acquired lower resp infections

nitrofurantoin PO or ceftriaxone IV

DOC for urinary tract infections

dicloxacillin or cephalexin or bactrim

DOC for staph in skin/soft tissue infections

pen VK, cephalexin

DOC for strep pyogenes in skin/soft tissue infections