Blind treatment of bacterial infection

Infection

Treatment

Tonsillitis⁶

Most sore throats are viral, but if bacterial tonsillitis is suspected:

Phenoxymethylpenicillin 500 mg QDS or 1 g BD for 10 days.

If allergic to penicillin, clarithromycin 250 mg-500 mg BD for 10 days.

Otitis media in childhood⁷

Many are viral - 80% resolve without antibiotics. If clinically appropriate:

Amoxicillin first-line - 40 mg/kg/day in three divided doses.
Maximum 1 g TDS for five days.

If allergic to penicillin: Clarithromycin or erythromycin first-line.

Rhinosinusitis⁸

Avoid antibiotics unless severe, or where symptoms are lasting more than 10 days. 80% resolve within 14 days without antibiotics.

First-line - phenoxymethylpenicillin 500 mg QDS for five days.

If allergic to penicillin, doxycycline 200 mg on the first day then 100 mg once daily for a further four days or clarithromycin 500 mg BD for five days.

If pregnant and allergic to penicillin, erythromycin 250-500 mg QDS for five days.

For persistent symptoms - co-amoxiclav 625 mg TDS for seven days - seek microbiology advice if allergic to penicillin.

Acute bronchitis/lower respiratory tract infection⁹

Only marginal benefits in otherwise healthy adults. Patient leaflets can reduce antibiotic use:

Doxycycline 200 mg stat then 100 mg OD for five days.

If the person is pregnant, amoxicillin 500 mg TDS for five days.

Alternatives include erythromycin or clarithromycin.

Acute exacerbation of chronic obstructive pulmonary disease¹⁰

Use antibiotics if there is increased dyspnoea

and

purulent sputum

and/or

increased sputum volume:

First-line - amoxicillin 500 mg TDS or doxycycline 200 mg stat then 100 mg OD or clarithromycin 500mg BD, for 5 days.

If resistance - co-amoxiclav 625 mg TDS for 5 days.

Community-acquired pneumonia⁹

Use CRB-65 score to guide appropriate management. See the separate Pneumonia article:

First-line: amoxicillin 500 mg-1 g TDS or clarithromycin 500 mg BD or doxycycline 200 mg stat the 100 mg OD for up to 10 days.

Consider risk factors for Staphylococcus aureus and Legionella spp.

Assess need for dual therapy for atypical organisms: amoxicillin and clarithromycin, or doxycycline alone.

Meningitis¹¹

Admit to hospital immediately:

Intramuscular or intravenous benzylpenicillin or cefotaxime prior to admission, unless there is history of anaphylaxis, (a history of a rash with penicillin is not a contra-indication).

Benzylpenicillin: adults and children 10 years and over: 1200 mg. Children 1-9 years: 600 mg. Children under 1 year: 300 mg.

Cefotaxime: age 12+ years: 1 gram. Age <12 years: 50 mg/kg.

Uncomplicated urinary tract infection (UTI) - ie no fever or flank pain^{12 13}

Amoxicillin resistance is common; therefore, ONLY use it if culture confirms susceptibility.

In the elderly (>65 years), do not treat asymptomatic bacteriuria; it occurs in 25% of women and 10% of men and is not associated with increased morbidity.

In the presence of a catheter, antibiotics will not eradicate bacteriuria; only treat if systemically unwell or if pyelonephritis is likely.

Do MSU on all treatment failures - extended-spectrum beta-lactamase enzyme-producing organisms increasing multiple resistance but still sensitive to nitrofurantoin.

Uncomplicated UTI (no fever or flank pain):

Use nitrofurantoin or trimethoprim first-line

Trimethoprim 200 mg BD, nitrofurantoin 50-100 mg QDS or 100 mg modified-release BD for three days if the eGFR is at least 45,

Second-line choices include pivmecillinam 200 mg TDS (400 mg TDS if resistance risk) or fosfomycin 3 g as a single dose.

Treat for three days in women and for seven days in men.

UTI in pregnancy:

Send MSU for culture and start antibiotics.

Short-term use of nitrofurantoin in pregnancy is unlikely to cause problems to the fetus.

First-line - nitrofurantoin 100 mg MR BD (avoid at term).

Second line - amoxicillin 500 mg TDS (if organism susceptible); treat for seven days or cefalexin 500 mg BD for seven days.

Children (see also separate Urinary Tract Infection in Children article):

Lower UTI: trimethoprim, second-line - cefalexin, trimethoprim or amoxicillin.

Upper UTI: cefalexin or co-amoxiclav.

Recurrent UTI in non-pregnant women (three or more UTIs/year):

See also the separate Recurrent Urinary Tract Infection article.

Consider prescribing vaginal oestrogen in postmenopausal women.

For prophylaxis use nitrofurantoin 50-100 mg or trimethoprim 100 mg OD at night (review at six months).

Skin/soft tissue infections^{14 15 16}

Impetigo:

Reserve topical antibiotics for very localised lesions to reduce risk resistance.

Consider hydrogen peroxide 1% cream applied 2-3 times daily for five days for people who are not systemically unwell or at a high risk of complications.

If meticillin-resistant S. aureus (MRSA) is suspected, consult microbiology.

First-line oral medication - flucloxacillin 500 mg or, if penicillin allergy, clarithromycin 250-500 mg BD; treat for seven days.

Topical - use fusidic acid TDS for five days.

Eczema:

Using antibiotics, or adding them to steroids, in eczema does not improve healing unless there are visible signs of infection.

Cellulitis:

Flucloxacillin 500 mg QDS for even days. Use clarithromycin or doxycycline if there is allergy to penicillin.

If febrile and ill, admit for IV treatment.

If penicillin-allergic and on statins use doxycycline 200 mg stat then 100 mg OD for seven days (a pragmatic alternative for the statin/macrolide interaction is to omit the statin for the duration of the antibiotic use).

If unresolving: clindamycin 300-450 mg QDS seven days.

In facial cellulitis, use co-amoxiclav 625 mg TDS for seven days.

Initially treat for seven days but continue for a further seven days if there is slow response.

Leg ulcers:

Bacteria will always be present. Antibiotics do not improve healing unless there is active infection. Culture swabs and review antibiotics after culture results.

Active infection indicated if there is cellulitis, increased pain, pyrexia, purulent exudate or odour.

If there is active infection, use flucloxacillin or clarithromycin as for cellulitis.

Human and animal bites:

Thorough irrigation is important.

Assess tetanus, rabies, HIV and hepatitis B/C risk.

Consider whether the bite and/or the person are high-risk. High-risk bites include those in the hands, feet, genitals, skin overlying cartilaginous structures or an area of poor circulation. High-risk people include those who have a comorbidity that increases the risk of serious wound infection, for example diabetes, immunosuppression, asplenia or decompensated liver disease.

Do not offer antibiotics for bites that have not broken the skin.

Consider antibiotics for bites which have broken the skin but not drawn blood if the bite is from a human and the person/bite is high-risk, or from a cat if the wound could be deep.

Offer antibiotics for human and cat bites that have broken the skin and drawn blood. Only offer antibiotics for dog bites in this situation if the bite has caused considerable deep tissue damage or is visibly contaminated (eg, with dirt or a tooth), or the person or bite is high-risk,

First-line is co-amoxiclav 375-625 mg TDS for seven days.

Second-line (for patients with penicillin allergy, or if co-amoxiclav is otherwise unsuitable) Metronidazole 400 mg TDS PLUS doxycycline 100 mg BD

Seek specialist advice if antibiotics are indicated and the person is pregnant and allergic to penicillin.

NB: doses are for adults unless otherwise stated - for further details see the British National Formulary.