Guidance

Recommendations

Recommendations

People have the right to be involved in discussions and make informed decisions about their care, as described in NICE's information on making decisions about your care.

Making decisions using NICE guidelines explains how we use words to show the strength (or certainty) of our recommendations, and has information about prescribing medicines (including off‑label use), professional guidelines, standards and laws (including on consent and mental capacity), and safeguarding.

1.1 Managing acute pyelonephritis

1.1.1

Be aware that acute pyelonephritis is an infection of one or both kidneys usually caused by bacteria travelling up from the bladder.

Treatment

1.1.2

In people aged 16 years and over with acute pyelonephritis, obtain a midstream urine sample before antibiotics are taken and send for culture and susceptibility testing.

1.1.5

Offer an antibiotic (see the recommendations on choice of antibiotic) to people with acute pyelonephritis. Take account of:

  • the severity of symptoms

  • the risk of developing complications, which is higher in people with known or suspected structural or functional abnormality of the genitourinary tract or immunosuppression

  • previous urine culture and susceptibility results

  • previous antibiotic use, which may have led to resistant bacteria.

1.1.6

When results of urine cultures are available:

  • review the choice of antibiotic and

  • change the antibiotic according to susceptibility results if the bacteria are resistant, using a narrow spectrum antibiotic wherever possible.

Advice when an antibiotic prescription is given

1.1.7

When an antibiotic is given, as well as the general advice on self-care, give advice about:

  • possible adverse effects of the antibiotic, particularly diarrhoea and nausea

  • nausea with vomiting also being a possible indication of worsening pyelonephritis

  • seeking medical help if:

    • symptoms worsen at any time or

    • symptoms do not start to improve within 48 hours of taking the antibiotic or

    • the person becomes systemically very unwell.

Reassessment

1.1.8

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.

Referral and seeking specialist advice

1.1.9

Refer people aged 16 years and over with acute pyelonephritis to hospital if they have any symptoms or signs suggesting a more serious illness or condition (for example, sepsis).

1.1.10

Consider referring or seeking specialist advice for people aged 16 years and over with acute pyelonephritis if they:

  • are significantly dehydrated or unable to take oral fluids and medicines or

  • are pregnant or

  • have a higher risk of developing complications (for example, people with known or suspected structural or functional abnormality of the genitourinary tract or underlying disease [such as diabetes or immunosuppression]).

For a short explanation of why the committee made these recommendations, see the evidence and committee discussion on choice of antibiotic.

Full details of the evidence and the committee's discussion are available in the evidence review.

1.2 Self-care

1.2.1

Advise people with acute pyelonephritis about using paracetamol for pain, with the possible addition of a low-dose weak opioid such as codeine for people over 12 years.

1.2.2

Advise people with acute pyelonephritis about drinking enough fluids to avoid dehydration.

For a short explanation of why the committee made these recommendations, see the evidence and committee discussion on self-care.

Full details of the evidence and the committee's discussion are available in the evidence review.

1.3 Choice of antibiotic

1.3.2

Give oral antibiotics first line if the person can take oral medicines, and the severity of their condition does not require intravenous antibiotics.

1.3.3

Review intravenous antibiotics by 48 hours and consider stepping down to oral antibiotics where possible.

Table 1 Antibiotics for non-pregnant women and men aged 16 years and over
Treatment Antibiotic, dosage and course length

First-choice oral antibiotics

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

Co‑amoxiclav (only if culture results available and susceptible):

500/125 mg three times a day for 7 to 10 days

Trimethoprim (only if culture results available and susceptible):

200 mg twice a day for 14 days

Ciprofloxacin (only if other first-choice antibiotics are unsuitable):

500 mg twice a day for 7 days

See the MHRA January 2024 advice on restrictions and precautions for using fluoroquinolone antibiotics because of the risk of disabling and potentially long‑lasting or irreversible side effects. Fluoroquinolones must now only be prescribed when other commonly recommended antibiotics are inappropriate

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

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

Ceftriaxone:

1 g to 2 g once a day

Gentamicin:

Initially 5 mg/kg to 7 mg/kg once a day, subsequent doses adjusted according to serum gentamicin concentration

Therapeutic drug monitoring and assessment of renal function is required (BNF information on gentamicin)

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)

Therapeutic drug monitoring and assessment of renal function is required (BNF information on amikacin)

Ciprofloxacin (only if other first-choice antibiotics are unsuitable):

400 mg twice or three times a day

See the MHRA January 2024 advice on restrictions and precautions for using fluoroquinolone antibiotics because of the risk of disabling and potentially long‑lasting or irreversible side effects. Fluoroquinolones must now only be prescribed when other commonly recommended antibiotics are inappropriate

Second-choice intravenous antibiotics

Consult a local microbiologist

See the BNF for appropriate use and dosing in specific populations, for example, hepatic impairment, renal impairment and breastfeeding, and administering intravenous antibiotics.

Check any previous urine culture and susceptibility results and antibiotic prescribing and choose antibiotics accordingly.

Review intravenous antibiotics by 48 hours and consider stepping down to oral antibiotics where possible. 

Table 2 Antibiotics for pregnant women aged 12 years and over
Treatment Antibiotic, dosage and course length

First-choice oral antibiotic

Cefalexin:

500 mg twice or three times a day (up to 1 g to 1.5 g three or four times a day for severe infections) for 7 to 10 days

First-choice intravenous antibiotic (if vomiting, unable to take oral antibiotics, or severely unwell)

Cefuroxime:

750 mg to 1.5 g three or four times a day

Second-choice antibiotics or when combining antibiotics if susceptibility or sepsis a concern

Consult local microbiologist

See the BNF for appropriate use and dosing in specific populations, for example, hepatic impairment and renal impairment, and administering intravenous antibiotics.

Check any previous urine culture and susceptibility results and antibiotic prescribing and choose antibiotics accordingly.

Review intravenous antibiotics by 48 hours and consider stepping down to oral antibiotics where possible.

Table 3 Antibiotics for children and young people under 16 years
Treatment Antibiotic, dosage and course length

Choice for children under 3 months

Refer to paediatric specialist and treat with intravenous antibiotics in line with the NICE guideline on fever in under 5s

First-choice oral antibiotic for children aged 3 months and over

Cefalexin:

3 months 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 year 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 years 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 years to 15 years, 500 mg twice or three times a day (up to 1 g to 1.5 g three or four times a day for severe infections) for 7 to 10 days

Co‑amoxiclav (only if culture results available and susceptible):

3 months 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 years 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 years 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 years 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) for children aged 3 months and over. Antibiotics may be combined if susceptibility or sepsis a concern

Co‑amoxiclav (only in combination or if culture results available and susceptible):

3 months to 15 years, 30 mg/kg three times a day (maximum 1.2 g three times a day)

Cefuroxime:

3 months to 15 years, 20 mg/kg three times a day (maximum 750 mg per dose), increased to 50 mg/kg to 60 mg/kg three or four times a day (maximum 1.5 g per dose) for severe infections

Ceftriaxone:

3 months to 11 years (up to 50 kg), 50 mg/kg to 80 mg/kg once a day (maximum 4 g per day)

9 years to 11 years (50 kg and above), 1 g to 2 g once a day

12 years to 15 years, 1 g to 2 g once a day

Gentamicin:

Initially 7 mg/kg once a day, subsequent doses adjusted according to serum gentamicin concentration

Therapeutic drug monitoring and assessment of renal function is required (BNFC information on gentamicin)

Amikacin:

Initially 15 mg/kg once a day, subsequent doses adjusted according to serum amikacin concentration

Therapeutic drug monitoring and assessment of renal function is required (BNFC information on amikacin)

Second-choice intravenous antibiotics for children aged 3 months and over

Consult a local microbiologist

See the BNF for children for appropriate use and dosing in specific populations, for example, hepatic and renal impairment, and administering intravenous antibiotics. See table 2 if a young woman is pregnant.

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.

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.

Review intravenous antibiotics by 48 hours and consider stepping down to oral antibiotics where possible for a total of 10 days. If intravenous treatment is not possible, consider intramuscular treatment if suitable.

For a short explanation of why the committee made these recommendations, see the evidence and committee discussion on choice of antibiotic, antibiotic course length and antibiotic route of administration.

Full details of the evidence and the committee's discussion are available in the evidence review.