Overview
This Guidelines summary sets out an antimicrobial prescribing strategy for acute pyelonephritis (upper urinary tract infection) in children, young people, and adults, who do not have a catheter. Recommendations include managing acute pyelonephritis, self-care, and choice of antibiotic. For a full set of recommendations, refer to the full guideline.
Choice of Antibiotic
- When prescribing an antibiotic for acute pyelonephritis, take account of local antimicrobial resistance data and follow:
- table 1 for non-pregnant women and men aged 16 years and over table 2 for pregnant women aged 12 years and over
- table 3 for children and young people under 16 years
- Give oral antibiotics first line if the person can take oral medicines, and the severity of their condition does not require intravenous antibiotics
- Review intravenous antibiotics by 48 hours and consider stepping down to oral antibiotics where possible
Algorithm 1: Prescribing Antimicrobials for Pyelonephritis (Acute)
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Table 1: Antibiotics for Non-Pregnant Women and Men Aged 16 Years and Over
Antibiotic[A] | Dosage and Course Length |
First-choice oral antibiotic[B] | |
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 (consider safety issues)[C] | 500 mg 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 susceptibility or sepsis a concern[B],[D] | |
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 to 2 g once a day |
Ciprofloxacin (consider safety issues)[D] | 400 mg twice or three times a day |
Gentamicin | Initially 5 to 7 mg/kg once a day, subsequent doses adjusted according to serum gentamicin concentration[E] |
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)[E] |
Second-choice intravenous antibiotic | |
Consult local microbiologist | |
[A] See British national formulary (BNF) for appropriate use and dosing in specific populations, for example, hepatic impairment, renal impairment and breastfeeding, and administering intravenous antibiotics [B] Check any previous urine culture and susceptibility results and antibiotic prescribing and choose antibiotics accordingly [C] See MHRA advice for restrictions and precautions for using fluoroquinolone antibiotics due to very rare reports of disabling and potentially long-lasting or irreversible side effects affecting musculoskeletal and nervous systems. Warnings include: stopping treatment at first signs of a serious adverse reaction (such as tendonitis), prescribing with special caution in people over 60 years and avoiding coadministration with a corticosteroid (March 2019) [D] Review intravenous antibiotics by 48 hours and consider stepping down to oral antibiotics where possible [E] Therapeutic drug monitoring and assessment of renal function is required (BNF, August 2018). |
Table 2: Antibiotics for Pregnant Women Aged 12 Years and Over
Antibiotic[A] | |
First-choice oral antibiotic[B] | |
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 |
First-choice intravenous antibiotic (if vomiting, unable to take oral antibiotics, or severely unwell)[B],[C] | |
Cefuroxime | 750 mg to 1.5 g three or four times a day |
Second-choice antibiotics or combining antibiotics if susceptibility or sepsis a concern | |
Consult local microbiologist | |
[A] See British national formulary (BNF) for appropriate use and dosing in specific populations, for example, hepatic impairment and renal impairment, and administering intravenous antibiotics [B] Check any previous urine culture and susceptibility results and antibiotic prescribing and choose antibiotics accordingly [C] 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
Antibiotic[A] | Dosage and Course Length[B] |
Children under 3 months | |
Refer to paediatric specialist and treat with intravenous antibiotics in line with the NICE guideline on fever in under 5s | |
Children aged 3 months and over | |
First-choice oral antibiotic[C] | |
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 |
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 concern[C],[D],[E] | |
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 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 to 80 mg/kg once a day (maximum 4 g per day) 9 to 11 years (50 kg and above), 1 to 2 g once a day 12 to 15 years, 1 to 2 g once a day |
Gentamicin | Initially 7 mg/kg once a day, subsequent doses adjusted according to serum gentamicin concentration[F] |
Amikacin | Initially 15 mg/kg once a day, subsequent doses adjusted according to serum amikacin concentration[F] |
Second-choice intravenous antibiotic | |
Consult local microbiologist | |
[A] 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 table 2 if a young woman is pregnant [B] 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 [C] 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 [D] Review intravenous antibiotics by 48 hours and consider stepping down to oral antibiotics where possible for a total of 10 days [E] If intravenous treatment is not possible, consider intramuscular treatment if suitable |
Managing Acute Pyelonephritis
- Be aware that acute pyelonephritis is an infection of one or both kidneys usually caused by bacteria travelling up from the bladder
Treatment
- 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
- In children and young people under 16 years with acute pyelonephritis, obtain a urine sample before antibiotics are taken and send for culture and susceptibility testing in line with the NICE guideline on urinary tract infection in under 16s
- Assess and manage children under 5 with acute pyelonephritis who present with fever as outlined in the NICE guideline on fever in under 5s
- 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
- 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
- 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
- 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
- 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)
- 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])
- Refer children and young people with acute pyelonephritis to hospital in line with the NICE guideline on urinary tract infection in under 16s
Self-care
- 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
- Advise people with acute pyelonephritis about drinking enough fluids to avoid dehydration