antibiotics for children and young people under 16 years old

Last edited 06/2021 and last reviewed 06/2021

Antibiotics for children and young people under 16 years

Children under 3months

• refer to paediatric specialist and treat with intravenous antibiotics

Children aged 3months and over

First-choice oral antibiotic3

• cefalexin
  • 3 to 11 months, 12.5 mg/kg or 125 mg twice a day for 7 to 10 days (25 mg/kg two to four times a day [maximum 1 g per dose four times a day] for severe infections)
  • 1 to 4 years, 12.5 mg/kg twice a day or 125 mg three times a day for 7 to 10 days (25 mg/kg two to four times a day [maximum 1 g per dose four times a day] for severe infections)
  • 5 to 11 years, 12.5 mg/kg twice a day or 250 mg three times a day for 7 to 10 days (25 mg/kg two to four times a day [maximum 1 g per dose four times a day] for severe infections)
  • 12 to 15 years, 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)
  • 3 to 11 months, 0.25 ml/kg of 125/31 suspension three times a day for 7 to 10 days (dose doubled in severe infection)
  • 1 to 5 years, 0.25 ml/kg of 125/31 suspension or 5 ml of 125/31 suspension three times a day for 7 to 10 days (dose doubled in severe infection)
  • 6 to 11 years, 0.15 ml/kg of 250/62 suspension or 5 ml of 250/62 suspension three times a day for 7 to 10 days (dose doubled in severe infection)
  • 12 to 15 years, 250/125 mg or 500/125 mg three times a day for 7 to 10 days

First-choice intravenous antibiotics (if vomiting, unable to take oral antibiotics or severely unwell). Antibiotics may be combined if susceptibility or sepsis a concern3, 4, 5

• co-amoxiclav (only in combination or if culture results available and susceptible)
  • OR
• cefuroxime
  • OR
• ceftriaxone
  • OR
• gentamicin
  • OR
• amikacin

Second-choice intravenous antibiotic > Consult local microbiologist

• 1 See British national formulary for children (BNFC) for appropriate use and dosing in specific populations, for example, hepatic and renal impairment, and administering intravenous antibiotics. See relevant antibiotic guidance if a young woman is pregnant.
• 2 The age bands apply to children of average size and, in practice, the prescriber will use the age bands in conjunction with other factors such as the severity of the condition being treated and the child's size in relation to the average size of children of the same age.
• 3 Check any previous urine culture and susceptibility results and antibiotic prescribing, and choose antibiotics accordingly. Where a child or young person is receiving prophylactic antibiotics, treatment should be with a different antibiotic, not a higher dose of the same antibiotic.
• 4 Review intravenous antibiotics by 48 hours and consider stepping down to oral antibiotics where possible for a total of 10 days.
• 5 If intravenous treatment is not possible, consider intramuscular treatment if suitable.
• 6 Therapeutic drug monitoring and assessment of renal function is required (BNFC, August 2018).

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

Reference:

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