Intravenous antibacterial prophylaxis should be given up to
30 minutes before the procedure.
postoperative doses may be given for prolonged procedures
or if there is major blood loss).
Obstetric and gynaecological surgery, antibacterial
. Single dose of i/v cefuroxime (additional intra-operative or
postoperative doses may be given for prolonged
procedures or if there is major blood loss).
Intravenous antibacterial prophylaxis should be given up
to 30 minutes before the procedure.
Substitute i/v clindamycin if history of allergy to
penicillins or cephalosporins. Add i/v teicoplanin (or
vancomycin) if high risk of meticillin-resistant
. Single dose of i/v cefuroxime + i/v metronidazole or i/v
gentamicin + i/v metronidazole or i/v co-amoxiclav alone
(additional intra-operative or postoperative doses may be
given for prolonged procedures or if there is major blood
Intravenous antibacterial prophylaxis should be given up to
30 minutes before the procedure.
Use single dose of i/v gentamicin + i/v metronidazole or
add i/v teicoplanin (or vancomycin) to other regimens if high
risk of meticillin-resistant Staphylococcus aureus (additional
intra-operative or postoperative doses may be given for
prolonged procedures or if there is major blood loss).
Where i/v metronidazole is suggested, it may alternatively
be given by suppository but to allow adequate absorption, it
should be given 2 hours before surgery.
prolonged procedures or if there is major blood loss).
If genital chlamydial infection cannot be ruled out, give
doxycycline p. 564 postoperatively.
Cardiology procedures, antibacterial prophylaxis
. Single dose of i/v cefuroxime alone or i/v flucloxacillin + i/v
gentamicin or i/v teicoplanin (or vancomycin) + i/v
gentamicin (additional intra-operative or postoperative
doses may be given for prolonged procedures or if there is
Intravenous antibacterial prophylaxis should be given up to
30 minutes before the procedure.
Use single dose of i/v teicoplanin (or vancomycin) + i/v
cefuroxime or i/v teicoplanin (or vancomycin) + i/v
gentamicin if high risk of meticillin-resistant Staphylococcus
aureus (additional intra-operative or postoperative doses
may be given for prolonged procedures or if there is major
Vascular surgery, antibacterial prophylaxis
Reconstructive arterial surgery of abdomen, pelvis or legs
. Single dose of i/v cefuroxime alone or i/v flucloxacillin + i/v
gentamicin p. 519 (additional intra-operative or
postoperative doses may be given for prolonged
procedures or if there is major blood loss).
Intravenous antibacterial prophylaxis should be given up to
30 minutes before the procedure.
Add i/v metronidazole p. 542 for patients at risk from
anaerobic infections including those with diabetes,
gangrene, or undergoing amputation. Use single dose of i/v
teicoplanin p. 532 (or vancomycin p. 534) + i/v gentamicin if
history of allergy to penicillins or cephalosporins, or if high
risk of meticillin-resistant Staphylococcus aureus (additional
intra-operative or postoperative doses may be given for
prolonged procedures or if there is major blood loss).
Infective endocarditis, antibacterial prophylaxis
NICE guidance: Antimicrobial prophylaxis against infective
endocarditis in adults and children undergoing interventional
procedures (March 2008, updated 2016)
. Chlorhexidine mouthwash is not recommended for the
prevention of infective endocarditis in at risk patients
Antibacterial prophylaxis is not routinely recommended for
the prevention of infective endocarditis in patients
undergoing the following procedures:
▶ upper and lower respiratory tract (including ear, nose, and
throat procedures and bronchoscopy);
▶ genito-urinary tract (including urological, gynaecological,
▶ upper and lower gastro-intestinal tract.
Whilst these procedures can cause bacteraemia, there is no
clear association with the development of infective
endocarditis. Prophylaxis may expose patients to the adverse
effects of antimicrobials when the evidence of benefit has
Any infection in patients at risk of endocarditis should be
investigated promptly and treated appropriately to reduce
infection is suspected, they should receive appropriate
antibacterial therapy that includes cover against organisms
that cause infective endocarditis.
Patients at risk of infective endocarditis should be:
▶ advised to maintain good oral hygiene;
▶ told how to recognise signs of infective endocarditis, and
advised when to seek expert advice.
Patients at risk of infective endocarditis include those with
valve replacement, acquired valvular heart disease with
stenosis or regurgitation, structural congenital heart disease
(including surgically corrected or palliated structural
conditions, but excluding isolated atrial septal defect, fully
repaired ventricular septal defect, fully repaired patent
ductus arteriosus, and closure devices considered to be
endothelialised), hypertrophic cardiomyopathy, or a
previous episode of infective endocarditis.
. Advice of a Working Party of the British Society for
Antimicrobial Chemotherapy is that patients who undergo
dermatological procedures do not require antibacterial
prophylaxis against endocarditis.
The British Association of Dermatologists Therapy
Guidelines and Audit Subcommittee advise that such
dermatological procedures include skin biopsies and
excision of moles or of malignant lesions.
Joint prostheses and dental treatment,
. Advice of a Working Party of the British Society for
Antimicrobial Chemotherapy is that patients with
prosthetic joint implants (including total hip
replacements) do not require antibiotic prophylaxis for
dental treatment. The Working Party considers that it is
unacceptable to expose patients to the adverse effects of
antibiotics when there is no evidence that such
prophylaxis is of any benefit, but that those who develop
any intercurrent infection require prompt treatment with
antibiotics to which the infecting organisms are sensitive.
BNF 78 Bacterial infection 509
The Working Party has commented that joint infections have
rarely been shown to follow dental procedures and are even
more rarely caused by oral streptococci.
Immunosuppression and indwelling intraperitoneal
Advice of a Working Party of the British Society for
Antimicrobial Chemotherapy is that patients who are
immunosuppressed (including transplant patients) and
patients with indwelling intraperitoneal catheters do not
require antibiotic prophylaxis for dental treatment provided
there is no other indication for prophylaxis.
The Working Party has commented that there is little
evidence that dental treatment is followed by infection in
immunosuppressed and immunodeficient patients nor is
there evidence that dental treatment is followed by infection
in patients with indwelling intraperitoneal catheters.
Blood infections, antibacterial
Septicaemia (community-acquired)
. A broad-spectrum antipseudomonal penicillin (e.g.
piperacillin with tazobactam p. 545, ticarcillin with
clavulanic acid p. 546) or a broad-spectrum cephalosporin
▶ If meticillin-resistant Staphylococcus aureus suspected, add
vancomycin p. 534 (or teicoplanin p. 532).
▶ If anaerobic infection suspected, add metronidazole p. 542
to broad-spectrum cephalosporin.
▶ If other resistant micro-organisms suspected, use a more
broad-spectrum beta-lactam antibacterial (e.g.
Septicaemia (hospital-acquired)
. A broad-spectrum antipseudomonal beta-lactam
antibacterial (e.g. piperacillin with tazobactam, ticarcillin
with clavulanic acid, ceftazidime p. 528, imipenem with
cilastatin p. 522, or meropenem)
▶ If meticillin-resistant Staphylococcus aureus suspected, add
▶ If anaerobic infection suspected, add metronidazole to
Septicaemia related to vascular catheter
▶ If Gram-negative sepsis suspected, especially in the
immunocompromised, add a broad-spectrum
▶ Consider removing vascular catheter, particularly if
infection caused by Staphylococcus aureus, pseudomonas,
If meningococcal disease suspected, a single dose of
benzylpenicillin sodium p. 547 should be given before urgent
transfer to hospital, so long as this does not delay the
transfer; cefotaxime p. 527 may be an alternative in
penicillin allergy; chloramphenicol p. 568 may be used if
history of immediate hypersensitivity reaction to penicillin
. Benzylpenicillin sodium or cefotaxime (or ceftriaxone
. If history of immediate hypersensitivity reaction to penicillin
or to cephalosporins, chloramphenicol
To eliminate nasopharyngeal carriage, ciprofloxacin p. 558,
or rifampicin p. 582, or ceftriaxone may be used.
Cardiovascular system infections,
Endocarditis: initial ‘blind’ therapy
. Native valve endocarditis, amoxicillin p. 548 (or ampicillin
▶ Consider adding low-dose gentamicin p. 519
▶ If penicillin-allergic, or if meticillin-resistant
Staphylococcus aureus suspected, or if severe sepsis, use
vancomycin p. 534 + low-dose gentamicin
▶ If severe sepsis with risk factors for Gram-negative
infection, use vancomycin + meropenem p. 523
. If prosthetic valve endocarditis, vancomycin + rifampicin
Endocarditis (native valve) caused by staphylococci
▶ Suggested duration of treatment 4 weeks (at least 6 weeks if
secondary lung abscess or osteomyelitis also present)
. If penicillin-allergic or if meticillin-resistant Staphylococcus
aureus, vancomycin + rifampicin
▶ Suggested duration of treatment 4 weeks (at least 6 weeks if
secondary lung absecess or osteomyelitis also present)
Endocarditis (prosthetic valve) caused by
. Flucloxacillin + rifampicin + low-dose gentamicin
▶ Suggested duration of treatment at least 6 weeks; review
need to continue gentamicin at 2 weeks—seek specialist
advice if gentamicin considered necessary beyond 2 weeks
. If penicillin-allergic or if meticillin-resistant Staphylococcus
aureus, vancomycin + rifampicin + low-dose gentamicin
▶ Suggested duration of treatment at least 6 weeks; review
need to continue gentamicin at 2 weeks—seek specialist
advice if gentamicin considered necessary beyond 2 weeks
Endocarditis caused by fully-sensitive streptococci
. Benzylpenicillin sodium p. 547
▶ Suggested duration of treatment 4–6 weeks (6 weeks for
prosthetic valve endocarditis)
. If penicillin-allergic, vancomycin (or teicoplanin p. 532) +
▶ Suggested duration of treatment 4–6 weeks (stop
Endocarditis caused by less-sensitive streptococci
. Benzylpenicillin sodium + low-dose gentamicin
▶ Suggested duration of treatment 4–6 weeks (6 weeks for
prosthetic valve endocarditis); review need to continue
gentamicin at 2 weeks—seek specialist advice if
gentamicin considered necessary beyond 2 weeks; stop
gentamicin at 2 weeks if micro-organisms moderately
. If penicillin-allergic or highly penicillin-resistant,
vancomycin (or teicoplanin) + low-dose gentamicin
▶ Suggested duration of treatment 4–6 weeks (6 weeks for
prosthetic valve endocarditis); review need to continue
gentamicin at 2 weeks—seek specialist advice if
gentamicin considered necessary beyond 2 weeks; stop
gentamicin at 2 weeks if micro-organisms moderately
Endocarditis caused by enterococci
. Amoxicillin (or ampicillin) + low dose gentamicin or
benzylpenicillin sodium + low-dose gentamicin
▶ Suggested duration of treatment 4–6 weeks (6 weeks for
prosthetic valve endocarditis); review need to continue
510 Bacterial infection BNF 78
gentamicin at 2 weeks—seek specialist advice if
gentamicin considered necessary beyond 2 weeks
. If penicillin-allergic or penicillin-resistant, vancomycin (or
teicoplanin) + low-dose gentamicin
▶ Suggested duration of treatment 4–6 weeks (6 weeks for
prosthetic valve endocarditis); review need to continue
gentamicin at 2 weeks—seek specialist advice if
gentamicin considered necessary beyond 2 weeks
. If gentamicin resistant, amoxicillin (or ampicillin)
▶ Add streptomycin p. 520 (if susceptible) for 2 weeks
▶ Suggested duration of treatment at least 6 weeks
Endocarditis caused by Haemophilus, Actinobacillus,
Cardiobacterium, Eikenella, and Kingella species
. Amoxicillin (or ampicillin) + low-dose gentamicin
▶ Suggested duration of treatment 4 weeks (6 weeks for
prosthetic valve endocarditis); stop gentamicin after
▶ If amoxicillin -resistant, ceftriaxone p. 528 (or cefotaxime
▶ Suggested duration of treatment 4 weeks (6 weeks for
prosthetic valve endocarditis); stop gentamicin after
Central nervous system infections,
Meningitis: initial empirical therapy
. Transfer patient to hospital urgently.
. If meningococcal disease (meningitis with non-blanching
rash or meningococcal septicaemia) suspected,
benzylpenicillin sodium p. 547 should be given before
transfer to hospital, so long as this does not delay the
transfer. If a patient with suspected bacterial meningitis
without non-blanching rash cannot be transferred to
hospital urgently, benzylpenicillin sodium should be given
before the transfer. Cefotaxime p. 527 may be an
alternative in penicillin allergy; chloramphenicol p. 568
may be used if history of immediate hypersensitivity
reaction to penicillin or to cephalosporins.
. In hospital, consider adjunctive treatment with
dexamethasone p. 675 (particularly if pneumococcal
meningitis suspected in adults), preferably starting before
or with first dose of antibacterial, but no later than
12 hours after starting antibacterial; avoid dexamethasone
in septic shock, meningococcal septicaemia, or if
immunocompromised, or in meningitis following surgery.
In hospital, if aetiology unknown:
. Adult and child 3 months–50 years, cefotaxime (or
▶ Consider adding vancomycin p. 534 if prolonged or
multiple use of other antibacterials in the last 3 months, or
if travelled, in the last 3 months, to areas outside the UK
with highly penicillin- and cephalosporin-resistant
▶ Suggested duration of treatment at least 10 days
. Adult over 50 years cefotaxime (or ceftriaxone) +
amoxicillin p. 548 (or ampicillin p. 550)
▶ Consider adding vancomycin if prolonged or multiple use
of other antibacterials in the last 3 months, or if travelled,
in the last 3 months, to areas outside the UK with highly
penicillin- and cephalosporin-resistant pneumococci.
▶ Suggested duration of treatment at least 10 days
Meningitis caused by meningococci
. Benzylpenicillin sodium or cefotaxime (or ceftriaxone)
▶ Suggested duration of treatment 7 days.
▶ If history of immediate hypersensitivity reaction to penicillin
or to cephalosporins, chloramphenicol
▶ Suggested duration of treatment 7 days.
Meningitis caused by pneumococci
▶ Consider adjunctive treatment with dexamethasone,
preferably starting before or with first dose of
antibacterial, but no later than 12 hours after starting
antibacterial (may reduce penetration of vancomycin into
▶ If micro-organism penicillin-sensitive, replace cefotaxime
▶ Suggested duration of antibacterial treatment 14 days
Meningitis caused by Haemophilus influenzae
▶ Consider adjunctive treatment with dexamethasone,
preferably starting before or with first dose of
antibacterial, but no later than 12 hours after starting
▶ Suggested duration of antibacterial treatment 10 days.
▶ For H. influenzae type b give rifampicin for 4 days before
hospital discharge to those under 10 years of age or to
those in contact with vulnerable household contacts
. If history of immediate hypersensitivity reaction to penicillin
or to cephalosporins, or if micro-organism resistant to
▶ Consider adjunctive treatment with dexamethasone,
preferably starting before or with first dose of
antibacterial, but no later than 12 hours after starting
▶ Suggested duration of antibacterial treatment 10 days.
▶ For H. influenzae type b give rifampicin for 4 days before
hospital discharge to those under 10 years of age or to
those in contact with vulnerable household contacts
. Amoxicillin (or ampicillin) + gentamicin p. 519
▶ Suggested duration of treatment 21 days.
▶ Consider stopping gentamicin after 7 days.
. If history of immediate hypersensitivity reaction to penicillin,
▶ Suggested duration of treatment 21 days.
Ear infections, antibacterial therapy
. Otitis externa can be triggered by a bacterial infection
caused by Pseudomonas aeruginosa or Staphylococcus
aureus. Consider systemic antibacterial if spreading
cellulitis or patient systemically unwell.
Choice of antibacterial therapy
Penicillin allergy or intolerance
. Clarithromycin p. 538 (or azithromycin p. 536 or
. Ciprofloxacin p. 558 (or an aminoglycoside)
For topical treatments, see Otitis externa, under Ear
BNF 78 Bacterial infection 511
. Acute otitis media is an inflammation in the middle ear
associated with effusion and accompanied by an ear
infection. Acute otitis media is commonly seen in children
and is generally caused by viruses (respiratory syncytial
virus and rhinovirus) or bacteria (Haemophilus influenzae,
Streptococcus pneumoniae, Streptococcus pyogenes, and
g Antibacterial therapy should be offered to children
with acute otitis media who are systemically very unwell,
have signs and symptoms of a more serious illness, or those
considered if otorrhoea (discharge following perforation of
the eardrum) is present, or in children under 2 years of age
with bilateral otitis media. h
Choice of antibacterial therapy in children
. First line:g amoxicillin p. 548. h
. Second line (worsening symptoms despite 2 to 3 days of
antibacterial treatment):g co-amoxiclav p. 551. h
Penicillin allergy or intolerance
. First line:g clarithromycin p. 538 or erythromycin
p. 539 (preferred in pregnancy). h
. Second line (worsening symptoms despite 2 to 3 days of
antibacterial treatment):gConsult local
Eye infections, antibacterial therapy
. Chloramphenicol p. 1173 eye drops.
Gastro-intestinal system infections,
. Frequently self-limiting and may not be bacterial.
▶ Antibacterial not usually indicated
. Frequently self-limiting; treat if immunocompromised or
. Clarithromycin p. 538 (or azithromycin p. 536 or
. Alternative, ciprofloxacin p. 558
▶ Strains with decreased sensitivity to ciprofloxacin isolated
. Treat invasive or severe infection. Do not treat less severe
infection unless there is a risk of developing invasive
infection (e.g. immunocompromised patients, those with
haemoglobinopathy, or children under 6 months of age).
. Ciprofloxacin or cefotaxime p. 527
. Antibacterial not indicated for mild cases.
. Ciprofloxacin or azithromycin
. Alternatives if micro-organism sensitive, amoxicillin p. 548
. Infections from Middle-East, South Asia, and South-East
Asia may be multiple-antibacterial-resistant and
. Cefotaxime (or ceftriaxone p. 528)
▶ azithromycin may be an alternative in mild or moderate
disease caused by multiple-antibacterial-resistant
. Alternative if micro-organism sensitive, ciprofloxacin
Clostridium difficile infection
. Clostridium difficile infection is caused by colonisation of
the colon with Clostridium difficile and production of toxin.
It often follows antibiotic therapy and is usually of acute
onset, but may become chronic. It is a particular hazard of
ampicillin p. 550, amoxicillin, co-amoxiclav p. 551,
second- and third-generation cephalosporins, clindamycin
p. 535, and quinolones, but few antibiotics are free of this
side-effect. Treatment options include metronidazole
p. 542, vancomycin p. 534, and fidaxomicin p. 570.
. For first episode of mild to moderate infection, oral
▶ Suggested duration of treatment 10–14 days
. For second or subsequent episode of infection, for severe
infection, for infection not responding to metronidazole , or
in patients intolerant of metronidazole, oral vancomycin
antibacterials, or for second or subsequent episode of
infection, fidaxomicin can replace vancomycin
▶ Suggested duration of treatment 10–14 days
. For infection not responding to vancomycin or fidaxomicin ,
for life-threatening infection, or in patients with ileus, oral
vancomycin + i/v metronidazole
▶ For infection not responding to vancomycin in patients
without life-threatening infection or ileus, fidaxomicin can
be used instead of vancomycin + metronidazole
▶ Suggested duration of treatment 10–14 days
. Ciprofloxacin or gentamicin p. 519 or a cephalosporin
. A cephalosporin + metronidazole or gentamicin +
metronidazole or gentamicin + clindamycin or piperacillin
Peritonitis: peritoneal dialysis-associated
. Vancomycin (or teicoplanin p. 532) + ceftazidime p. 528
added to dialysis fluid or vancomycin added to dialysis
fluid + ciprofloxacin by mouth
▶ Suggested duration of treatment 14 days or longer
▶ Suggested duration of treatment 5–7 days (or high-dose
metronidazole as a single dose)
. Alternatively, topical metronidazole for 5 days or topical
512 Bacterial infection BNF 78
Uncomplicated genital chlamydial infection, nongonococcal urethritis, and non-specific genital
. Contact tracing recommended.
. Azithromycin p. 536 or doxycycline p. 564
▶ Suggested duration of treatment azithromycin as a single
dose or doxycycline for 7 days
. Alternatively, erythromycin p. 539.
▶ Suggested duration of treatment 14 days
depends on locality where infection acquired.
. Azithromycin + i/m ceftriaxone p. 528
▶ Suggested duration of treatment is a single-dose of each
. Alternatively, when parenteral administration is not possible,
▶ Suggested duration of treatment is a single-dose of each
. Alternatively, if micro-organism is sensitive to a quinolone,
ciprofloxacin p. 558 + azithromycin
▶ Suggested duration of treatment is a single-dose of each
. Pharyngeal infection, azithromycin + i/m ceftriaxone
▶ Suggested duration of treatment is a single-dose of each
. Contact tracing recommended.
. Doxycycline + metronidazole + single-dose of i/m
ceftriaxone or ofloxacin p. 561 + metronidazole
▶ Suggested duration of treatment 14 days (except i/m
▶ In severely ill patients initial treatment with doxycycline +
i/v ceftriaxone + i/v metronidazole, then switch to oral
treatment with doxycycline + metronidazole to complete
Early syphilis (infection of less than 2 years)
. Contact tracing recommended.
. Benzathine benzylpenicillin [unlicensed]
▶ Suggested duration of treatment single-dose (repeat dose
after 7 days for women in the third trimester of pregnancy)
. Alternatively, doxycycline or erythromycin
▶ Suggested duration of treatment 14 days
Late latent syphilis (asymptomatic infection of
. Contact tracing recommended.
▶ Benzathine benzylpenicillin [unlicensed]
▶ Suggested duration of treatment once weekly for 2 weeks
▶ Suggested duration of treatment 28 days
Asymptomatic contacts of patients with infectious
▶ Suggested duration of treatment 14 days
Musculoskeletal system infections,
. Seek specialist advice if chronic infection or prostheses
▶ Consider adding fusidic acid p. 571 or rifampicin p. 582 for
▶ Suggested duration of treatment 6 weeks for acute infection
. If penicillin-allergic, clindamycin p. 535
▶ Consider adding fusidic acid or rifampicin for initial
▶ Suggested duration of treatment 6 weeks for acute infection
. If meticillin-resistant Staphylococcus aureus suspected,
vancomycin p. 534 (or teicoplanin p. 532)
▶ Consider adding fusidic acid or rifampicin for initial
▶ Suggested duration of treatment 6 weeks for acute infection
. Seek specialist advice if prostheses present.
▶ Suggested duration of treatment 4–6 weeks (longer if
. If penicillin-allergic, clindamycin
▶ Suggested duration of treatment 4–6 weeks (longer if
. If meticillin-resistant Staphylococcus aureus suspected,
▶ Suggested duration of treatment 4–6 weeks (longer if
. If gonococcal arthritis or Gram-negative infection suspected,
cefotaxime p. 527 (or ceftriaxone p. 528)
▶ Suggested duration of treatment 4–6 weeks (longer if
infection complicated; treat gonococcal infection for
Nose infections, antibacterial
Acute sinusitis is generally triggered by a viral infection,
although occasionally it may become complicated by a
bacterial infection caused by Streptococcus pneumoniae,
Haemophylus influenzae, Moraxella catharrhalis, or
Staphylococcus aureus. For further information see Sinusitis
g Antibacterial therapy should only be offered to patients
with acute sinusitis who are systemically very unwell, have
signs and symptoms of a more serious illness, those who are
at high-risk of complications due to pre-existing
comorbidities, or whenever bacterial sinusitis is suspected.
Patients presenting with symptoms for around 10 days or
more with no improvement may be prescribed a back-up
antibiotic prescription, which can be used if symptoms do
not improve within 7 days or if they worsen significantly at
any time. hFor further information see, Sinusitis (acute)
Choice of antibacterial therapy
▶ g Non-life threatening symptoms:
phenoxymethylpenicillin p. 548.
BNF 78 Bacterial infection 513
▶ Systemically very unwell, signs and symptoms of a more
serious illness, or at high-risk of complications: coamoxiclav p. 551. h
. Second line (worsening symptoms despite 2 or 3 days of
▶ g Non-life threatening symptoms: co-amoxiclav.
▶ Systemically very unwell, signs and symptoms of a more
serious illness or at high-risk of complications: consult
Penicillin allergy or intolerance
. First line:g doxycycline p. 564 or clarithromycin p. 538
(erythromycin p. 539 in pregnancy).
. Second line (worsening symptoms despite 2 or 3 days of
antibiotic treatment): Consult local microbiologist.h
Sinusitis (acute): antimicrobial prescribing. National
Institute for Health and Care Excellence. NICE guideline 79.
Antibacterial drugs should only be prescribed for the
treatment of oral infections on the basis of defined need.
They may be used in conjunction with (but not as an
alternative to) other appropriate measures, such as providing
drainage or extracting a tooth.
The ‘blind’ prescribing of an antibacterial for unexplained
pyrexia, cervical lymphadenopathy, or facial swelling can
lead to difficulty in establishing the diagnosis. In severe oral
infections, a sample should always be taken for bacteriology.
Oral infections which may require antibacterial treatment
include acute periapical or periodontal abscess, cellulitis,
acutely created oral-antral communication (and acute
sinusitis), severe pericoronitis, localised osteitis, acute
necrotising ulcerative gingivitis, and destructive forms of
chronic periodontal disease. Most of these infections are
readily resolved by the early establishment of drainage and
removal of the cause (typically an infected necrotic pulp).
Antibacterials may be required if treatment has to be
delayed, in immunocompromised patients, or in those with
conditions such as diabetes or Paget’s disease. Certain rarer
infections including bacterial sialadenitis, osteomyelitis,
actinomycosis, and infections involving fascial spaces such
as Ludwig’s angina, require antibiotics and specialist
Antibacterial drugs may also be useful after dental surgery
in some cases of spreading infection. Infection may spread to
involve local lymph nodes, to fascial spaces (where it can
cause airway obstruction), or into the bloodstream (where it
can lead to cavernous sinus thrombosis and other serious
complications). Extension of an infection can also lead to
maxillary sinusitis; osteomyelitis is a complication, which
usually arises when host resistance is reduced.
If the oral infection fails to respond to antibacterial
treatment within 48 hours the antibacterial should be
changed, preferably on the basis of bacteriological
investigation. Failure to respond may also suggest an
incorrect diagnosis, lack of essential additional measures
(such as drainage), poor host resistance, or poor patient
Combination of a penicillin (or a macrolide) with
metronidazole p. 542 may sometimes be helpful for the
treatment of severe oral infections or oral infections that
have not responded to initial antibacterial treatment.
. Phenoxymethylpenicillin p. 548 is effective for
Amoxicillin p. 548 is as effective as phenoxymethylpenicillin
but is better absorbed; however, it may encourage
emergence of resistant organisms.
Like phenoxymethylpenicillin, amoxicillin is ineffective
against bacteria that produce beta-lactamases.
Amoxicillin may be useful for short course oral regimens.
spreading cellulitis or dental infection not responding to
first-line antibacterial treatment.
The cephalosporins offer little advantage over the penicillins
in dental infections, often being less active against
anaerobes. Infections due to oral streptococci (often termed
viridans streptococci) which become resistant to penicillin
are usually also resistant to cephalosporins. This is of
importance in the case of patients who have had rheumatic
fever and are on long-term penicillin therapy. Cefalexin
p. 524 and cefradine p. 525 have been used in the treatment
In adults, tetracyclines can be effective against oral
anaerobes but the development of resistance (especially by
oral streptococci) has reduced their usefulness for the
treatment of acute oral infections; they may still have a role
in the treatment of destructive (refractory) forms of
periodontal disease. Doxycycline p. 564 has a longer
duration of action than tetracycline p. 567 or oxytetracycline
p. 567 and need only be given once daily; it is reported to be
more active against anaerobes than some other
Doxycycline may have a role in the treatment of recurrent
aphthous ulceration, or as an adjunct to gingival scaling and
root planing for periodontitis.
The macrolides are an alternative for oral infections in
penicillin-allergic patients or where a beta-lactamase
producing organism is involved. However, many organisms
are now resistant to macrolides or rapidly develop
resistance; their use should therefore be limited to short
Clindamycin p. 535 should not be used routinely for the
treatment of oral infections because it may be no more
effective than penicillins against anaerobes and there may be
cross-resistance with erythromycin-resistant bacteria.
Clindamycin can be used for the treatment of dentoalveolar
abscess that has not responded to penicillin or to
Metronidazole is an alternative to a penicillin for the
treatment of many oral infections where the patient is
for the treatment of acute necrotising ulcerative gingivitis
(Vincent’s infection) and pericoronitis; amoxicillin is a
suitable alternative. For these purposes metronidazole for
3 days is sufficient, but the duration of treatment may need
to be longer in pericoronitis. Tinidazole p. 544 is licensed for
the treatment of acute ulcerative gingivitis.
514 Bacterial infection BNF 78
Respiratory system infections,
Epiglottitis (Haemophilus influenzae)
. Cefotaxime p. 527 (or ceftriaxone p. 528)
. If history of immediate hypersensitivity reaction to penicillin
or to cephalosporins, chloramphenicol p. 568
Bronchiectasis (non-cystic fibrosis), acute
Bronchiectasis is a persistent or progressive condition,
caused by chronic inflammatory damage to the airways and
is characterised by thick-walled, dilated bronchi. Signs and
symptoms may range from intermittent expectoration and
infection, to chronic cough, persistent daily production of
sputum, bacterial colonisation, and recurrent infections. An
acute exacerbation is defined as sustained deterioration of
the patient’s signs and symptoms from their baseline, and
presents with worsening local symptoms, with or without
increased wheeze, breathlessness or haemoptysis and may
be accompanied by fever or pleurisy.
g Obtain a sputum sample and send for culture and
susceptibility testing. Antibacterial therapy should be given
to all patients with an acute exacerbation. h
For patients receiving prophylactic antibacterial therapy,
switching from intravenous to oral antibacterials, and for
advice to be given to patients, see Antibacterials, principles
g Refer patients to hospital if they have signs or
symptoms suggestive of a more serious illness such as
cardiorespiratory failure or sepsis. h
g Reassess if symptoms worsen rapidly or significantly at
. Other diagnoses such as pneumonia, or signs and
symptoms of a more serious illness such as
cardiorespiratory failure, or sepsis;
. Previous antibacterial use that may have led to resistance.
Review choice of antibacterial if susceptibility results
indicate bacterial resistance and symptoms are not
improving—consult local microbiologist as needed. h
Choice of antibacterial therapy
. g The recommended total duration of treatment is
Treatment should be guided by the most recent sputum
culture and susceptibility results when available.
Seek specialist advice for patients whose symptoms are not
improving with repeated courses, or who are resistant to, or
cannot take oral antibacterials. h
▶ g Amoxicillin p. 548, clarithromycin p. 538, or
▶ Alternative if at high risk of treatment failure (repeated
courses of antibacterials, previous culture with resistant or
atypical bacteria, or high risk of complications): coamoxiclav p. 551, or levofloxacin p. 559. h
. Intravenous first line (severely unwell or unable to take
▶ g Co-amoxiclav, piperacillin with tazobactam p. 545, or
g For patients with repeated acute exacerbations, a trial
of antibacterial prophylaxis may be given on specialist advice
Chronic obstructive pulmonary disease, acute
An acute exacerbation of chronic obstructive pulmonary
disease (COPD) is a sustained worsening of symptoms from
the patient’s usual stable state, that is beyond the usual day
to day variations. Many exacerbations are not caused by
bacterial infections, but instead can be triggered by other
factors such as smoking or viral infections.
g Consider antibacterial treatment taking into account:
▶ The severity of symptoms, sputum colour changes and
increases in volume and thickness;
▶ The need for hospital admission;
▶ Previous exacerbations and hospital admission history,
and risk of developing complications. h
For other considerations such as in patients receiving
prophylactic antibacterial therapy, switching from
intravenous to oral antibacterials, and for advice to be given
to patients, see Antibacterials, principles of therapy p. 505.
g Refer patients to hospital if they have signs or
symptoms suggestive of a more serious illness such as
cardiorespiratory failure or sepsis. h
. g Reassess if symptoms worsen rapidly or significantly
▶ Other diagnoses such as pneumonia, or signs and
symptoms of a more serious illness such as
cardiorespiratory failure, or sepsis;
▶ Previous antibacterial use that may have led to resistance;
▶ Sending a sputum sample for testing if there is no
improvement after antibacterial therapy and this has not
Review choice of antibacterial if susceptibility results
indicate bacterial resistance and symptoms are not
improving—consult local microbiologist as needed. h
Choice of antibacterial therapy
g The recommended total duration of treatment is
Treatment should be guided by the most recent sputum
culture and susceptibility results when available.
Seek specialist advice for patients whose symptoms are not
improving with repeated courses, or who are resistant to, or
cannot take oral antibacterials. h
▶ g Amoxicillin, clarithromycin, or doxycycline.
▶ Alternative if at high risk of treatment failure (repeated
courses of antibacterials, previous culture with resistant or
atypical bacteria, or high risk of complications): coamoxiclav, or levofloxacin. h
. Oral second line (if no improvement after at least 2 to
▶ g Use a first line antibacterial from a different class to
the antibacterial used previously.
when sensitivities are available and there is good reason to
use co-trimoxazole over single antibacterials). h
. Intravenous first line (severely unwell or unable to take
▶ g Amoxicillin, co-amoxiclav, clarithromycin, cotrimoxazole, or piperacillin with tazobactam. h
. Intravenous second line :g Choice should be made in
consultation with a local microbiologist. h
For further information on COPD, see Chronic obstructive
Acute cough is usually self-limiting and often resolves
within 3–4 weeks without antibacterials. It is most
commonly caused by a viral upper respiratory tract infection,
BNF 78 Bacterial infection 515
but can have other infective causes such as acute bronchitis
or pneumonia, or non-infective causes such as interstitial
lung disease or gastro-oesophageal reflux disease.
g Patients should be advised that an acute cough is
usually self-limiting and to manage their symptoms using
suppressants, however there is limited evidence to support
the use of such products. For more information, see
Aromatic inhalations, cough preparations and systemic nasal
Patients with an acute cough who are systemically very
unwell should be offered immediate antibacterial treatment.
Do not routinely offer an antibacterial to treat an acute
cough associated with an upper respiratory tract infection or
acute bronchitis in patients who are not systemically very
unwell or at higher risk of complications. h
Patients with a pre-existing co-morbidity, young children
who were born prematurely, and patients aged over 65 years
of age and the presence of certain criteria (hospitalisation in
the previous year, type 1 or 2 diabetes, history of congestive
heart failure, or currently taking oral corticosteroids) are
considered to be at a higher risk of complications if they
present with an acute cough.g Immediate or back-up
antibacterial treatment should be considered in these
patients based on the face-to-face clinical examination. If
back-up treatment is given, advise patients to start
treatment if symptoms worsen rapidly or significantly at any
For general advice to give to patients, see Antibacterials,
g Seek specialist advice, or refer patients with an acute
cough to hospital if they have signs or symptoms of a more
serious illness or condition. h
g Reassess if symptoms worsen rapidly or significantly
taking into account alternative diagnoses, signs or
symptoms suggestive of a more serious condition, and
previous antibacterial use which may have led to resistant
Choice of antibacterial therapy
g The recommended duration of oral treatment is 5 days.
. First lineg Doxycycline p. 564.
▶ Alternative first line choices: amoxicillin p. 548,
clarithromycin p. 538, or erythromycin p. 539. h
▶ gAmoxicillin or erythromycin.h
Community-acquired pneumonia: low-severity
. Amoxicillin (or ampicillin p. 550)
▶ Pneumococci with decreased penicillin sensitivity being
isolated, but not yet common in UK.
▶ If atypical pathogens suspected, add clarithromycin (or
azithromycin p. 536 or erythromycin).
▶ If staphylococci suspected (e. g. in influenza or measles),
▶ Suggested duration of treatment 7 days (14–21 days for
infections caused by staphylococci)
. Alternatives, doxycycline or clarithromycin (or
▶ Suggested duration of treatment 7 days (14–21 days for
infections caused by staphylococci)
Community-acquired pneumonia: moderateseverity
. Amoxicillin (or ampicillin) + clarithromycin (or
azithromycin or erythromycin) or doxycycline alone
▶ Pneumococci with decreased penicillin sensitivity being
isolated, but not yet common in UK.
▶ If meticillin-resistant Staphylococcus aureus suspected, add
vancomycin p. 534 (or teicoplanin p. 532).
▶ Suggested duration of treatment 7 days (14–21 days for
infections caused by staphylococci)
Community-acquired pneumonia: high-severity
. Benzylpenicillin sodium p. 547 + clarithromycin (or
azithromycin or erythromycin) or benzylpenicillin sodium
▶ If meticillin-resistant Staphylococcus aureus suspected, add
▶ Suggested duration of treatment 7–10 days (may extend
treatment to 14–21 days in some cases e.g. if staphylococci
. If life-threatening infection, or if Gram-negative infection
clarithromycin (or azithromycin or erythromycin)
▶ If meticillin-resistant Staphylococcus aureus suspected, add
▶ Suggested duration of treatment 7–10 days (may extend
treatment to 14–21 days in some cases e.g. if staphylococci
or Gram-negative enteric bacilli suspected)
. Alternatives if life-threatening infection, or if Gram-negative
infection suspected, or if co-morbidities present, or if living in
long-term residential or nursing home, cefuroxime p. 526+
clarithromycin (or azithromycin or erythromycin) or
cefotaxime p. 527 (or ceftriaxone p. 528) + clarithromycin
(or azithromycin or erythromycin)
▶ If meticillin-resistant Staphylococcus aureus suspected, add
▶ Suggested duration of treatment 7–10 days (may extend
treatment to 14–21 days in some cases e.g. if staphylococci
or Gram-negative enteric bacilli suspected)
Pneumonia possibly caused by atypical pathogens
. Clarithromycin (or azithromycin or erythromycin)
▶ If high-severity Legionella infection, add rifampicin p. 582
▶ Suggested duration of treatment 14 days (usually 7–10 days
. Alternative if Legionella infection suspected, a quinolone
▶ If high-severity Legionella infection, add clarithromycin
(or azithromycin or erythromycin) or rifampicin for the
▶ Suggested duration of treatment usually 7–10 days
. Alternative for chlamydial or mycoplasma infections,
▶ Suggested duration of treatment 14 days
. Early-onset infection less than 5 days after admission to
hospital), co-amoxiclav or cefuroxime
▶ If life-threatening infection, or if history of antibacterial
▶ Suggested duration of treatment 7 days
. Late-onset infection (more than 5 days after admission to
hospital), an antipseudomonal penicillin (e.g. piperacillin
with tazobactam p. 545) or a broad-spectrum
cephalosporin (e.g. ceftazidime p. 528) or another
antipseudomonal beta-lactam or a quinolone (e.g.
▶ If meticillin-resistant Staphylococcus aureus suspected, add
▶ For severe illness caused by Pseudomonas aeruginosa,
consider adding an aminoglycoside.
516 Bacterial infection BNF 78
▶ Suggested duration of treatment 7 days (longer if
Pseudomonas aeruginosa confirmed)
Skin infections, antibacterial
Impetigo: small areas of skin infected
. Seek local microbiology advice before using topical
▶ Suggested duration of treatment 7 days is usually adequate
. Alternatively, if meticillin-resistant Staphylococcus aureus,
▶ Suggested duration of treatment 7 days is usually adequate
Impetigo: widespread infection
▶ If streptococci suspected in severe infection, add
phenoxymethylpenicillin p. 548.
▶ Suggested duration of treatment 7 days.
. If penicillin-allergic, oral clarithromycin p. 538 (or
azithromycin p. 536 or erythromycin p. 539)
▶ Suggested duration of treatment 7 days.
. Phenoxymethylpenicillin or benzylpenicillin sodium p. 547
▶ If severe infection, replace phenoxymethylpenicillin or
benzylpenicillin sodium with high-dose flucloxacillin
▶ Suggested duration of treatment at least 7 days.
. If penicillin-allergic, clindamycin p. 535 or clarithromycin
(or azithromycin or erythromycin)
▶ Suggested duration of treatment at least 7 days
. If streptococcal infection confirmed, replace flucloxacillin
with phenoxymethylpenicillin or benzylpenicillin sodium
▶ If Gram-negative bacteria or anaerobes suspected, use
broad-spectrum antibacterials.
. If penicillin-allergic, clindamycin or clarithromycin (or
azithromycin or erythromycin) or vancomycin p. 534 (or
▶ If Gram-negative bacteria suspected, use broad-spectrum
Cleanse wound thoroughly. For tetanus-prone wound, give
history and risk of infection). Consider rabies prophylaxis for
bites from animals in endemic countries. Assess risk of
blood-borne viruses (including HIV, hepatitis B and C) and
give appropriate prophylaxis to prevent viral spread.
. If penicillin-allergic, doxycycline p. 564 + metronidazole
Mastitis during breast-feeding
Treat if severe, if systemically unwell, if nipple fissure
present, if symptoms do not improve after 12–24 hours of
effective milk removal, or if culture indicates infection.
Continue breast-feeding or expressing milk during
▶ Suggested duration of treatment 10–14 days.
. If penicillin-allergic, erythromycin
▶ Suggested duration of treatment 10–14 days.
ANTIBACTERIALS › AMINOGLYCOSIDES
These include amikacin p. 518, gentamicin p. 519, neomycin
sulfate p. 520, streptomycin p. 520, and tobramycin p. 520.
All are bactericidal and active against some Gram-positive
and many Gram-negative organisms. Amikacin, gentamicin,
and tobramycin are also active against Pseudomonas
aeruginosa; streptomycin is active against Mycobacterium
tuberculosis and is now almost entirely reserved for
The aminoglycosides are not absorbed from the gut
(although there is a risk of absorption in inflammatory bowel
disease and liver failure) and must therefore be given by
injection for systemic infections.
Gentamicin is the aminoglycoside of choice in the UK and
is used widely for the treatment of serious infections. It has a
broad spectrum but is inactive against anaerobes and has
poor activity against haemolytic streptococci and
pneumococci. When used for the ‘blind’ therapy of
undiagnosed serious infections it is usually given in
conjunction with a penicillin or metronidazole p. 542 (or
both). Gentamicin is used together with another antibiotic
for the treatment of endocarditis. Streptomycin may be used
as an alternative in gentamicin-resistant enterococcal
Loading and maintenance doses of gentamicin may be
calculated on the basis of the patient’s weight and renal
function (e.g. using a nomogram); adjustments are then
made according to serum-gentamicin concentrations. High
doses are occasionally indicated for serious infections,
especially in the neonate, in the patient with cystic fibrosis,
or in the immunocompromised patient. Whenever possible
treatment should not exceed 7 days.
Amikacin is more stable than gentamicin to enzyme
inactivation. Amikacin is used in the treatment of serious
infections caused by gentamicin-resistant Gram-negative
Tobramycin has similar activity to gentamicin. It is slightly
more active against Ps. aeruginosa but shows less activity
against certain other Gram-negative bacteria. Tobramycin
can be administered by nebuliser or by inhalation of powder
on a cyclical basis (28 days of tobramycin followed by a
28-day tobramycin-free interval) for the treatment of
chronic pulmonary Ps. aeruginosa infection in cystic fibrosis;
however, resistance may develop and some patients do not
Neomycin sulfate is too toxic for parenteral administration
and can only be used for infections of the skin or mucous
membranes or to reduce the bacterial population of the
colon prior to bowel surgery or in hepatic failure. Oral
administration may lead to malabsorption. Small amounts of
neomycin sulfate may be absorbed from the gut in patients
with hepatic failure and, as these patients may also be
uraemic, cumulation may occur with resultant ototoxicity.
Once daily administration of aminoglycosides is more
convenient, provides adequate serum concentrations, and in
many cases has largely superseded multiple-daily dose
regimens (given in 2–3 divided doses during the 24 hours).
Local guidelines on dosage and serum concentrations should
be consulted. A once-daily, high-dose regimen of an
aminoglycoside should be avoided in patients with
endocarditis due to Gram-positive bacteria, HACEK
BNF 78 Bacterial infection 517
endocarditis, burns of more than 20% of the total body
surface area, or creatinine clearance less than 20 mL/minute.
There is insufficient evidence to recommend a once daily,
high-dose regimen of an aminoglycoside in pregnancy.
Serum concentration monitoring avoids both excessive and
subtherapeutic concentrations thus preventing toxicity and
ensuring efficacy. Serum-aminoglycoside concentrations
should be monitored in patients receiving parenteral
aminoglycosides and must be determined in the elderly, in
obesity, and in cystic fibrosis, or if high doses are being
given, or if there is renal impairment.
Aminoglycosides (by injection) f
l CONTRA-INDICATIONS Myasthenia gravis (aminoglycosides
may impair neuromuscular transmission)
(aminoglycosides may impair neuromuscular
transmission) . if possible, dehydration should be corrected
before starting an aminoglycoside . whenever possible,
parenteral treatment should not exceed 7 days
▶ Common or very common Skin reactions .tinnitus
▶ Frequency not known Confusion . lethargy . nephrotoxicity
SIDE-EFFECTS, FURTHER INFORMATION Ototoxicity and
nephrotoxicity are important side-effects to consider with
aminoglycoside therapy. Nephrotoxicity occurs most
commonly in patients with renal impairment, who may
require reduced doses; monitoring is particularly
l PREGNANCY There is a risk of auditory or vestibular nerve
damage in the infant when aminoglycosides are used in
the second and third trimesters of pregnancy. The risk is
greatest with streptomycin. The risk is probably very small
with gentamicin and tobramycin, but their use should be
Monitoring If given during pregnancy, serumaminoglycoside concentration monitoring is essential.
l RENAL IMPAIRMENT Excretion of aminoglycosides is
principally via the kidney and accumulation occurs in renal
impairment. Ototoxicity and nephrotoxicity occur
commonly in patients with renal failure.
▶ In adults A once-daily, high-dose regimen of an
aminoglycoside should be avoided in patients with a
creatinine clearance less than 20 mL/minute.
▶ In children A once-daily, high-dose regimen of an
aminoglycoside should be avoided in children over
1 month of age with a creatinine clearance less than
Dose adjustments If there is impairment of renal function,
the interval between doses must be increased; if the renal
impairment is severe, the dose itself should be reduced as
Monitoring Serum-aminoglycoside concentrations must
be monitored in patients with renal impairment; earlier
and more frequent measurement of aminoglycoside
concentration may be required.
▶ Serum concentrations Serum concentration monitoring
avoids both excessive and subtherapeutic concentrations
thus preventing toxicity and ensuring efficacy.
Serum-aminoglycoside concentrations should be measured
in all patients receiving parenteral aminoglycosides and
must be determined in obesity, if high doses are being given
▶ In adults Serum aminoglycoside concentrations must be
determined in the elderly. In patients with normal renal
function, aminoglycoside concentrations should be
measured after 3 or 4 doses of a multiple daily dose
regimen and after a dose change. For multiple daily dose
regimens, blood samples should be taken approximately
1 hour after intramuscular or intravenous administration
(‘peak’ concentration) and also just before the next dose
(‘trough’ concentration). If the pre-dose (‘trough’)
concentration is high, the interval between doses must be
increased. If the post-dose (‘peak’) concentration is high,
the dose must be decreased. For once daily dose regimens,
consult local guidelines on serum concentration
▶ In children In children with normal renal function,
aminoglycoside concentrations should be measured after 3
or 4 doses of a multiple daily dose regimen. Blood samples
should be taken just before the next dose is administered
(‘trough’ concentration). If the pre-dose (‘trough’)
concentration is high, the interval between doses must be
increased. For multiple daily dose regimens, blood samples
should also be taken approximately 1 hour after
intramuscular or intravenous administration (‘peak’
concentration). If the post-dose (‘peak’) concentration is
high, the dose must be decreased.
▶ Renal function should be assessed before starting an
aminoglycoside and during treatment.
▶ Auditory and vestibular function should also be monitored
Serious Gram-negative infections resistant to gentamicin
▶ BY INTRAMUSCULAR INJECTION, OR BY SLOW INTRAVENOUS
INJECTION, OR BY INTRAVENOUS INFUSION
▶ Adult: 15 mg/kg daily in 2 divided doses, increased to
22.5 mg/kg daily in 3 divided doses for up to 10 days,
higher dose to be used in severe infections; maximum
1.5 g per day; maximum 15 g per course
Serious Gram-negative infections resistant to gentamicin
▶ Adult: Initially 15 mg/kg (max. per dose 1.5 g once
daily), dose to be adjusted according to serumamikacin concentration; maximum 15 g per course
DOSES AT EXTREMES OF BODY-WEIGHT
▶ To avoid excessive dosage in obese patients, use ideal
weight for height to calculate dose and monitor serumamikacin concentration closely
l INTERACTIONS → Appendix 1: aminoglycosides
▶ Frequency not known Apnoea . neuromuscular blockade . paralysis
▶ With intravenous use Multiple daily dose regimen: one-hour
(‘peak’) serum concentration should not exceed
30 mg/litre; pre-dose (‘trough’) concentration should be
less than 10 mg/litre. Once daily dose regimen: pre-dose
(‘trough’) concentration should be less than 5 mg/litre.
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