The following is based on current BNF guidelines:

Respiratory system

Condition Recommended treatment
Exacerbations of chronic bronchitis Amoxicillin or tetracycline or clarithromycin
Uncomplicated community-acquired pneumonia Amoxicillin(Doxycycline or clarithromycin in penicillin allergic, add flucloxacillin if staphylococci suspected e.g. In influenza)
Pneumonia possibly caused by atypical pathogens Clarithromycin
Hospital-acquired pneumonia Within 5 days of admission: co-amoxiclav or cefuroximeMore than 5 days after admission: piperacillin with tazobactam OR a broad-spectrum cephalosporin (e.g. ceftazidime) OR a quinolone (e.g. ciprofloxacin)

Urinary tract

Condition Recommended treatment
Lower urinary tract infection Trimethoprim or nitrofurantoin. Alternative: amoxicillin or cephalosporin
Acute pyelonephritis Broad-spectrum cephalosporin or quinolone
Acute prostatitis Quinolone or trimethoprim

Skin

Condition Recommended treatment
Impetigo Topical hydrogen peroxide, oral flucloxacillin or erythromycin if widespread
Cellulitis Flucloxacillin(clarithromycin, erythromycin or doxycycline if penicillin-allergic)
Cellulitis (near the eyes or nose) Co-amoxiclav(clarithromycin, + metronidazole if penicillin-allergic)
Erysipelas Flucloxacillin* (clarithromycin, erythromycin or doxycycline if penicillin-allergic)
Animal or human bite Co-amoxiclav(doxycycline + metronidazole if penicillin-allergic)
Mastitis during breast-feeding Flucloxacillin

Ear, nose & throat

Condition Recommended treatment
Throat infections Phenoxymethylpenicillin(erythromycin alone if penicillin-allergic)
Sinusitis Phenoxymethylpenicillin
Otitis media Amoxicillin(erythromycin if penicillin-allergic)
Otitis externa** Flucloxacillin(erythromycin if penicillin-allergic)
Periapical or periodontal abscess Amoxicillin
Gingivitis: acute necrotising ulcerative Metronidazole

Genital system

Condition Recommended treatment
Gonorrhoea Intramuscular ceftriaxone
Chlamydia Doxycycline or azithromycin
Pelvic inflammatory disease Oral ofloxacin + oral metronidazole or intramuscular ceftriaxone + oral doxycycline + oral metronidazole
Syphilis Benzathine benzylpenicillin or doxycycline or erythromycin
Bacterial vaginosis Oral or topical metronidazole or topical clindamycin

Gastrointestinal

Condition Recommended treatment
Clostridioides difficile First episode: oral vancomycinSecond or subsequent episode of infection: oral fidaxomicin
Campylobacter enteritis Clarithromycin
Salmonella (non-typhoid) Ciprofloxacin
Shigellosis Ciprofloxacin