Antibiotics for non-pregnant women and men aged 16 years and over

Treatment

• Oral or intravenous antibiotics
  • oral antibiotics should be given first line if the person can take oral medicines, and the severity of their condition does not require intravenous antibiotics
  • if intravenous antibiotics then review intravenous antibiotics by 48 hours and consider stepping down to oral antibiotics where possible

Reassessment

• reassess if symptoms worsen at any time, or do not start to improve within 48 hours of taking the antibiotic, taking account of:
  • other possible diagnoses
  • any symptoms or signs suggesting a more serious illness or condition, such as sepsis
  • previous antibiotic use, which may have led to resistant bacteria.

Antibiotics1 for non-pregnant women and men aged 16 years and over

First-choice oral antibiotic2

• cefalexin - 500 mg twice or three times a day (up to 1 to 1.5 g three or four times a day for severe infections) for 7 to 10 days
  • OR
• co-amoxiclav (only if culture results available and susceptible) - 500/125 mg three times a day for 7 to 10 days
  • OR
• trimethoprim (only if culture results available and susceptible) - 200 mg twice a day for 14 days
  • OR
• ciprofloxacin (consider safety issues3) - 500mg twice a day for 7 days

First choice intravenous antibiotics (if vomiting, unable to take oral antibiotics, or severely unwell). Antibiotics may be combined if susceptibilty or sepsis a concern 2, 4

• co-amoxiclav (only in combination or if culture results available and susceptible)
  • 1.2 g three times a day Cefuroxime 750 mg to 1.5 g three or four times a day
    
    
  • OR
• ceftriaxone
  • 1 to 2 g once a day
    
    
  • OR
• ciprofloxacin (consider safety issues3)
  • 400 mg twice or three times a day
    
    
  • OR
• gentamicin
  • Initially 5 mg/kg to 7 mg/kg once a day, subsequent doses adjusted according to serum gentamicin concentration5
    
    
  • OR
• amikacin Initially
  • 15 mg/kg once a day (maximum per dose 1.5 g once a day), subsequent doses adjusted according to serum amikacin concentration (maximum 15 g per course)
    
    
• 1 check British national formulary (BNF) for appropriate use and dosing in specific populations, for example, hepatic impairment, renal impairment and breastfeeding, and administering intravenous antibiotics.
• 2 check any previous urine culture and susceptibility results and antibiotic prescribing and choose antibiotics accordingly.
• 3 the European Medicines Agency's Pharmacovigilance Risk Assessment Committee has recommended restricting the use of fluoroquinolone antibiotics following a review of disabling and potentially long-lasting side effects mainly involving muscles, tendons, bones and the nervous system (press release October 2018), but they are an option in acute pyelonephritis, which is a severe infection.
• 4 review intravenous antibiotics by 48 hours and consider stepping down to oral antibiotics where possible.
• 5 Therapeutic drug monitoring and assessment of renal function is required (BNF, August 2018)

Reference:

• NICE (October 2018). Pyelonephritis (acute): antimicrobial prescribing
• Public Health England (June 2021). Managing common infections: guidance for primary care