National Antibiotic Guidelines

Overview

The BNF has set national guidelines on what antibiotics to use in different bacterial infections. Local policies and guides may be used in areas where resistance and sensitivity patterns vary.

Respiratory infections

Infective COPD exacerbation:

• 1^st-line: amoxicillin or tetracycline or clarithromycin

Uncomplicated community-acquired pneumonia:

• 1^st-line: amoxicillin
• If allergic/unsuitable: doxycycline or clarithromycin
• If Staphylococcus aureus is suspected (e.g. post-influenza pneumonia), add flucloxacillin

Atypical pneumonia:

• 1^st-line: clarithromycin

Hospital-acquired pneumonia:

• Within 5 days of admission: co-amoxiclav or cefuroxime
• >5 days of admission: piperacillin with tazobactam or ceftazidime or ciprofloxacin

Genitourinary infections

Lower urinary tract infection:

• 1^st-line: trimethoprim or nitrofurantoin
• If allergic/unsuitable: amoxicillin or cephalosporin

Acute pyelonephritis:

• 1^st-line: broad-spectrum cephalosporin or quinolone

Acute prostatitis:

• 1^st-line: quinolone or trimethoprim

Chlamydia:

• 1^st-line: oral doxycycline for 7 days
• If allergic/unsuitable/pregnant: azithromycin, erythromycin, or amoxicillin

Gonorrhoea:

• 1^st-line: intramuscular ceftriaxone
• If allergic/inappropriate: single dose oral cefixime + single dose oral azithromycin

Pelvic inflammatory disease:

• 1^st-line: oral ofloxacin + oral metronidazole or IM ceftriaxone + oral metronidazole + oral doxycycline

Syphilis:

• 1^st-line: intramuscular benzathine benzylpenicillin
• If allergic/unsuitable: doxycycline or erythromycin

Bacterial vaginosis:

• 1^st-line: oral/topical metronidazole or topical clindamycin

Musculoskeletal infections

Osteomyelitis:

• 1^st-line: flucloxacillin
• If allergic/inappropriate: clindamycin

Septic arthritis:

• 1^st-line: flucloxacillin
• If allergic/inappropriate: clindamycin
• If gonococcal infection suspected: ceftriaxone or cefotaxime

Skin infections

Animal or human bite:

• 1^st-line: co-amoxiclav
• If allergic/unsuitable: doxycycline + metronidazole

Cellulitis:

• 1^st-line: flucloxacillin
• If allergic/unsuitable: clarithromycin, erythromycin, or doxycycline

Cellulitis near eyes or nose:

• 1st-line: co-amoxiclav 
• If allergic/unsuitable: clarithromycin + metronidazole

Erysipelas:

• 1^st-line: oral flucloxacillin
• If allergic/unsuitable: clindamycin

Impetigo:

• 1^st-line: topical hydrogen peroxide
• If widespread: oral flucloxacillin or erythromycin

Mastitis:

• 1^st-line: flucloxacillin
• If allergic/unsuitable: erythromycin or clarithromycin

Ear, nose, throat, and mouth infections

Tonsillitis/pharyngitis::

• 1^st-line: phenoxymethylpenicillin
• If allergic/unsuitable: erythromycin

Sinusitis:

• 1^st-line: phenoxymethylpenicillin
• If allergic/unsuitable: doxycycline or erythromycin or clarithromycin

Otitis externa:

• 1^st-line: topical antibiotic or combined topical antibiotic + steroid
• If spreading: flucloxacillin
• If allergic/unsuitable: erythromycin

Otitis media:

• 1^st-line: amoxicillin
• If allergic/unsuitable: erythromycin

Acute necrotising ulcerative gingivitis:

• 1^st-line: metronidazole

Gastrointestinal infections

Clostridioides difficile:

• First episode: oral vancomycin
• Second/subsequent: oral fidaxomicin

Campylobacter:

• 1^st-line: clarithromycin

Salmonella (non-typhoid):

• 1^st-line: ciprofloxacin

Shigella:

• 1^st-line: ciprofloxacin

Diverticulitis:

• Oral first-line: co-amoxiclav
  • If allergic/inappropriate: cefalexin + metronidazole or trimethoprim + metronidazole
• Intravenous first-line: co-amoxiclav + metronidazole or cefuroxime + metronidazole or amoxicillin + gentamicin + metronidazole