Antibiotic
Class
Penicillin G
Standard
Penicillins
(β-lactam)
Penicillin V
Methicillin
Nafcillin
Dicloxacillin
Standard
Penicillins
(β-lactam)
Anti- Staph
Penicillins
(β-lactam)
Anti-Staph
Penicillins
(β-lactam)
Anti-Staph
Penicillins
(β-lactam)
MOA
Antibacterial
Penetration
Clearance
Spectrum
INHIBITORS OF CELL WALL SYNTHESIS
NOT CSF
Interfere with last
Gram +,
(unless
Renal
step of CWS:
spirochetes,
(unchanged)
inflamed
cross-linkage step;
some
meninges),
lysis occurs
anaerobes
NOT prostate,
bone or eye
Same as above
Same as above
Same as above
Same as above
As above, esp.
β-lactamase
producing
Staph.
Same as above
Adverse Effects /
Contraindications
Special
Considerations
Beware of allergies;
Renal insufficiency:
adjust dose
(seizures at high
doses)
Must be given IV;
Short half-life
Same as above
Renal
Same as above
Same as above
Renal
Nephrotoxic
Same as above
Renal
Same as Pen G (Not
Oral use; Only for
minor infections
(dental);
Given IV for serious
systemic infections;
Nafcillin preferred; βlactamase resistant
Same as above
nephrotoxic)
Same as above
Same as above
Same as above
Renal
Same as above
Renal
Ampicillin
Aminopenicillins
(β-lactam)
Same as above
Same as Pen G
plus Gram–
bacilli / rods
Amoxicillin
Aminopenicillins
(β-lactam)
Same as above
Same as Pen G
plus Gram–
bacilli / rods
Same as above
Renal
Same as Pen G
Resistance a
problem;
Superinfections (C.
dificile) common;
↓ effectiveness of
birth-control pills
Same as above
Administered orally
(children) for mild
local Staph infections.
Used to treat serious
infections by
penicillin susceptible
organisms, incl.
anaerobes, some
Gram-; use w/ βlactamase inhibitor
(sublactam)
Used prophylactically
by dentists; DOC for
URI, sinusitis, otitis,
lower resp. infections;
use w/ β-lactamase
inhibitor
(calvulonate)
Antibiotic
Ticarcillin
Piperacillin
Class
AntiPseudomonal
Penicillins
(β-lactam)
AntiPseudomonal
Penicillins
(β-lactam)
MOA
Same as above
Same as above
Cefazolin
1st gen.
Cephalosporins
(β-lactam)
Same as above
Cephalexin
1st gen.
Cephalosporins
(β-lactam)
Same as above
Cefoxitin
2nd gen.
Cephalosporins
(β-lactam)
Same as above
Cefuroxime
2nd gen.
Cephalosporins
(β-lactam)
Same as above
Antibacterial
Spectrum
As above, plus
Gram- bacilli
(Klebsiella,
Enterobacter,
Pseudomonas)
Same as above
Pen G
substitute; also
for Proteus, E.
coli, Klebsiella
Same as above
Penetration
Clearance
Adverse Effects /
Contraindications
Same as above
Renal
Same as Pen G
Same as above
Renal
Same as Pen G
Same as above
Potentially
nephrotoxic; 5-15%
cross-reactivity with
penicillin allergies
– only use if delayed
type allergy to pen.
Parenteral; surgical
prophylaxis when
poss. skin microbes
involved
Ineffective against
MRSA, Listeria, C.
dificile, enterococci
Oral;
Ineffective against
MRSA, Listeria, C.
dificile, enterococci
Same as above
Renal
Same as above
Renal
As above, plus
Haemophilus,
some
Enterobacter
& Neisseria
(HENPEcK)
Same as Pen
G
Same as above
CSF
(Penetrates
BBB)
Same as above
Renal
Same as above
Renal
Same as above
Special
Considerations
Due to development
of resistance, usually
given in combination
with aminoglycoside
Parenteral; good
against B. fragilis
(anaerobe), For
interabdom. sepsis,
gyn. sepsis; colorectal
surgery
Parenteral;
Cefuroxime axetil =
oral; For bronchitis,
pneumonia in elderly,
immunocompromised
Antibiotic
Class
MOA
Cefixime
3rd gen.
Cephalosporins
(β-lactam)
Same as above
Ceftriaxone
Imipenem
Vancomycin
3rd gen.
Cephalosporins
(β-lactam)
Carbapenems
(β-lactam)
Same as above
Same as above
Inhibits CWS at an
earlier step than
the β-lactams
Antibacterial
Spectrum
Less effective
for Gram+,
extended
range against
Gram- bacilli
(HENPEcK +
other enterics)
Penetration
Clearance
Adverse Effects /
Contraindications
Special
Considerations
Same as Pen
G
Renal
Same as above
Oral, once daily
Hepatic
Same as above
GI upset, skin rash,
reaction at infusion
site, seizures in
patients with renal
insufficiency
Same as above
Good CSF
penetration,
and bone
Broadest
spectrum:
Gram- and +,
anaerobes
(incl. B.
fragilis), some
Pseudomonas
Good
distribution in
skin, soft
tissue, bone,
joints, CSF
Renal
Gram+;
effective
against some
MRSA
Inflammation
allows
penetration
into meninges
Renal
Fever, chills,
phlebitis at infusion
site, tachycardia,
hypotension; Shock
& flushing due to
histamine release if
rapid infusion;
Ototoxicity,
nephrotoxicity;
allergies
Parenteral; DOC for
Lyme disease and
meningitis
Always administered
with Cilastatin (IV),
otherwise inactivated
in renal tubules:
Primaxin = Imipenem
+ Cilastatin; Resistant
to most βlactamases; use for
organisms resistant to
other drugs (pen, etc);
DOC for Enterobacter
Synergism with
aminoglycosides;
Penicillin substitute;
Restricted use for
serious infections due
to β-lactam resistant
Gm+ organisms; Slow
IV drip, orally only
for C. difficile colitis
Antibiotic
Class
MOA
Antibacterial
Penetration
Clearance
Spectrum
INHIBITORS OF PROTEIN SYNTHESIS
Gentamicin
Aminoglycosides
Binds 30S (and
50S) subunit,
inhibits initiation
of protein
synthesis
Gram-, (some
Gram+) aerobic
only
NOT CSF,
eye, or
respiratory
syst.
Renal
Good in bone.
Streptomycin
Aminoglycosides
Binds 30S
subunit, inhibits
initiation of
protein synthesis
Gramaerobic only
Tobramycin
Aminoglycosides
Binds 30S (and
50S) subunit,
inhibits initiation
of protein
synthesis
Tetracycline
Tetracyclines
Binds 30S
subunit, inhibits
binding of a.a.tRNA;
bacteriostatic
Same as above
Renal
Gramaerobic only
Same as above
Renal
Broad
spectrum:
Gram- and +
and obligate
anaerobes,
intracellular
CSF;
concentrates
in liver,
kidney,
spleen, skin,
calcifying
tissues
Renal
Adverse Effects /
Contraindications
Worst ototoxicity
of aminoglycosides;
nephrotoxicity,
vestibular damage,
Neuromuscular
paralysis at high
conc.
Major resistance
problem;
irreversible
vestibular damage,
fetal hearing loss
(contraindicated w/
pregnancy);
Neuromuscular
paralysis at high
conc.
Ototoxicity,
nephrotoxicity,
vestibular damage;
Neuromuscular
paralysis at high
conc.
Phototoxicity ;
hepatotoxicity;
Contraindicated in
pregnant ♀ and
children under 8;
C.dificile colitis;
↓ effectiveness of
bcp’s; ↑ effects of
warfarin
Special
Considerations
Concentrationdependent killing,
significant postantibiotic effect (once
daily dosing); Combine
with β-lactams; Used
w/Vancomycin for
MRSA
Concentrationdependent killing,
significant postantibiotic effect;
Second-line anti-TB;
plague; tularemia (w/
penicillin)
Concentrationdependent killing,
significant postantibiotic effect; More
expensive than
Gentamicin
Major drug for
rickettsial diseases
and cholera,
Mycoplasma,
Chlamydia, Lyme
disease
Antibiotic
Class
MOA
Antibacterial
Spectrum
Penetration
Clearance
Adverse Effects /
Contraindications
Special
Considerations
Doxycycline
Tetracyclines
Same as above
Same as above
Hepatic
Same as above
Same as above
Erythromycin
Macrolides
Irreversibly binds
to 50S subunit,
inhibits
translocation step
of prot. synthesis
Prostate;
concentrates
in liver,
macrophages
Hepatic
Clarithromycin
Macrolides
Same as above
Same as above
Same as above
Renal
Azithromycin
Macrolides
Same as above
Same as above
Same as above
Hepatic
Clindamycin
Lincosamides
Binds to 50S
subunit to prevent
protein synthesis –
bacteriostatic to
bactericidal
Gram+
aerobes,
Gram- and +
anaerobes,
esp. B. fragilis
Concentrates
in bone –
NOT CSF
Hepatic
Binds 30S
subunit, inhibits
binding of a.a.tRNA;
bacteriostatic
Same as
Penicillin G,
also H.
influenzae, N.
meningitis, N.
gonorrheae,
Chlamydia,
Mycoplasma
Inhibits p450
(potentiates other
drug fx);
contraindicated with
hepatic dysfunction;
GI distress, temp.
ototoxicity;
resistance
Inhibits p450
(potentiates other
drug fx); resistance
Temporary
ototoxicity;
resistance a major
issue
Diarrhea;
Significant risk of
superinfection (C.
difficile); Drug
interference with
chloramphenicol
or Macrolides;
May inhibit NMJ
Alternative to
Penicillin G for
allergic patients; DOC
for Chlamydia
during pregnancy
Longer half life than
erythromycin, less GI
upset
Rapidly absorbed,
well tolerated orally;
DOC for
Legionnaire’s disease
DOC for severe
anaerobic infections
(Bacteroides, etc.);
taken orally or IV
Antibiotic
MOA
Antibacterial
Spectrum
Penetration
Clearance
Chloramphenicol
Binds to 50S
subunit, inhibits
peptidyl
transferase bacteriostatic
Broad
spectrum:
Gram- and +,
rickettsiae,
Chlamydia,
anaerobes
Well
distributed,
including
CSF,
intracellular
Hepatic
metabolism
then renal
excretion
Streptogramins
Bind two
different sites on
50S subunit –
bacteriostatic or
bactericidal
Gram+ cocci;
Legionella, M.
pneumoniae,
Chlamydia
pneumoniae
Linezolid
Metronidazole
Class
Mostly
hepatic
Gram+ cocci,
80% renal –
Prevents
bacilli,
but no
formation of 70S
ribosome –
anaerobes and
dosage
Unique effect,
aerobes;
adjustment
precedes steps
Listeria
needed for
inhibited by other monocytogenes
renal insuff.
PSI’s
INHIBITORS OF NUCLEIC ACID SYNTHESIS
Only active in
Hepatic
When activated,
Most tissues,
metabolism,
obligate
attacks, fragments
incl. bone and mostly renal
anaerobes:
Bacteroides,
excretion
bacterial DNA
CSF
Clostridium;
also protozoa
Adverse Effects /
Contraindications
BAD! Severe bone
marrow aplasia;
Gray baby
syndrome;
superinfections
(pseudomemb. colitis);
allergies; Inhibits
p450, so drug
interactions
Pain/phlebitis at
infusion site;
arthralgias and
myalgias; Inhibits
p450, so drug
interactions
Seems welltolerated;
thrombocytopenia,
GI distress, HA,
rash; NO EFFECT
on p450
Nausea, HA,
dizziness; Alcohol
contraindicated;
peripheral
neuropathy with
prolonged use
Special
Considerations
Few uses due to
adverse effects; Good
to treat S. typhi;
Refractory cases of
meningitis or patients
with β-lactam
allergies, brain
abscesses or
intraabdominal infect.
RESERVED for
serious infections with
resistant Gram + bugs
like E. faecium,
MRSA; IV slow drip,
NOT with
saline/heparin
RESERVED for
multi-drug resistant
strains of S. aureus, E.
faecium, S.
pneumoniae
MRSA DOC
DOC for
Bacteroides; Good
for endocarditis, brain
abscesses, C. difficile
colitis
Antibiotic
Class
MOA
Antibacterial
Spectrum
Penetration
Clearance
Ciprofloxacin
Quinolones and
Fluoroquinolones
Inhibit DNA
gyrase, so DNA
replication
blocked bactericidal
Gram – cocci
and bacilli
High levels in
bone,
prostate,
kidney
Hepatic and
renal
(beware
renal insuf.)
Rifampin
Rifamycins
Inhibits RNA
polymerase bactericidal
Many Gramand +, esp.
Mycobacterium
Distributes
well,
including CSF
Adverse Effects /
Contraindications
N/V, HA, diz;
nephrotoxicity,
phototoxicity;
Contraindicated in
pregnancy,
children arthropathy;
Inhibits p450, so
drug interactions;
w/ NSAIDS ↑ CNS
stim.effects seizures
Hepatic
metabolism
and
recirculation;
renal and
hepatic
elimination
NOT given as single
agent due to resistance;
Hepatic
metabolism,
renal
excretion
(beware
renal insuf.)
Nephrotox; allergies;
Hepatotoxicity;
Induces p450, so ↓
effect of bcp’s,
anticoag’s,
estrogens,
glucocort’s
Special
Considerations
DOC for UTI’s,
prostatitis; synergism
with β-lactams;
CF-associated
Pseudomonas
infections
Mainstay for TB
treatment (w/
Isoniazid); MRSA;
INHIBITORS OF METABOLISM
Resistance;
Sulfamethoxazole
Trimethoprim
Sulfonamides
Inhibits
dihydropteroate
synthetase (folate
synthesis)
Inhibits
dihydrofolate
reductase (folate
synthesis)
Nocardia,
Chlamydia, E.
coli, Proteus,
H. influenzae,
S. pyogenes, S.
pneumoniae
Well
distributed,
including CSF
Similar to
sulfonamides,
but 20-50X
more potent
Concentrates
in acidic
prostate and
vaginal fluids
Similar to
above
Kernicterus contraindicated in
pregnant ♀ and
newborns; Anemia
(w/G6PD def.?);
Inhibits p450
Same as above;
permanent renal
damage if poor
renal fxn; AIDS
patients adverse rxns
Also remember the β-lactamase inhibitors: Clavulanic acid, Sulbactam and Tazobactam
For UTI’s, usu. in
combination with
trimethoprim; otitis,
bronchitis, sinusitis, P.
carinii pneumonia
Combined with
Sulfamethoxazole (=Cotrimoxazole); UTI;
prostatitis; also see
above