Antibiotics key summaries
- Common antibiotics mechanism of action (MOA)
Drug class MOA Spectrum - Use Main Pt Other
Bactericidal or ses counselli information
bacteriostatic ng
Beta-lactams Inhibit Broad ampicillin: Penicilli Take Broad spectrum:
+ Penicillin bacterial (ampicillin: utis, otitis n ampicilli Maculopapular
+ Cephalosporins cell wall high media, allergy n, co- rash commonly
+ Carbapenems synthesis resistance – copd; (beta- amoxicla occurs but does
+ monobactams amoxicillin & meningiti lactams v, not usually
co-amoxiclav s (pen g - cross- flucloxac indicate true
are less parentera sensitivi illin, pen pencillin allergy
resistant l only); ty), v on an (i.e. Immediate
derivatives; rtis in cholest empty confluent
cephalosporin children atic stomach rash/anaphylaxis)
s); narrow e.g. strep jaundic & - avoid in blind
(pen g, pen v); throat, e (co- amoxicill treatment of sore
penicillinase tonsilitis amoxicl in can be throat (risk of
resistant (pen v – av & taken rash in
(flucloxacillin); oral, for flucloxa before glandular/Epstein
antipseudomo minor cillin or after bar virus fever);
nal infections use food do not give
(piperacillin + ); should penicillin
tazobactam & penicillin- not intrathecally;
ticaricillin + resistant exceed Cephalosporins:m
clavulanic staph skin 14 days ay give 3rd gen or
acid) – infections use), cefuroxime (2nd
bactericidal except antibio gen) in penicillin
mrsa bic hypersensitivity;
(flucloxaci associat excreted renally
llin), ed (penicillin &
pseudom colitis cephalosporins)
onal
infection,
Cephalos
porins: uti
(pregnanc
y or
second
line),
meningiti
s, CAP,
sinusitis,
otits
media
Glycopeptides e.g. Inhibit Narrow - Mrsa & Nephro Report Only active
Vancomycin cell wall bactericidal antibiotic toxicity hearing against gram
Teicoplanin, synthesis associate - renally loss, positive bacteria
televancin & d colitis cleared, tinnitus including mrsa;
assembly (vancomy ototoxi (=discon Narrow
, cin), hap city, tinue), therapeutic
last-line thromb vertigo index; avoid
(sole use ophlebi vancomycin in
of tis pregnancy unless
televancin (most essential;
) commo Vancomycin &
n), red- teicoplanin: not
man used orally for
syndro systemic
me, infections
blood
dyscrasi
as
Quinolones e.g. Inhibit Broad - Lower Seizure Driving, Avoid in
Ciprofloxacin bacterial bactericidal rtis, utis, s, antacids/ pregnancy &<18s
(choice) DNA avoid in tendon zinc/iron (arthropathy);
replicatio mrsa damage , milk, quinolones are
n (resistanc , qt photose second or third
e) prolnga nsitivity line options due
tion, to risk of
arthrop resistance;
athy Moxifloxacin –
highest risk of qt
prolongation &
life threatening
hepatotoxicity –
reserved as last
line
Nalidixic acid –
sole use:
uncomplicated
UTI & avoid in
egfr < 20;
Interactions:
theophylline (pd
& pk effects),
nsaids, li +
ciprofloxacin =
seizure
Aminoglycosides Inhibit Broad - Severe Nephro Report Given
e.g. Gentamicin bacterial bactericidal sepsis, toxicity hearing parenterally - not
(choice), Amikacin, protein pyelonep – loss, absorbed by gut;
Tobramycin synthesis hritis, renally tinnitus, not for more than
by complicat cleared, vertigo 7 days;
binding ed uti, ototoxi Narrow
irreversib endocardi city, cns therapeutic index
ly to 30S tis, cystic disturb Avoid in
ribosoma fibrosis ance pregnancy
l subunit (tobramyc (cied in (gentamicin only
in via myasth if essential)
inhaler), enia Gentamicin:
