Antibiotics and the Kidney
Last updated 3rd December 2020
Introduction
- Problems can arise either because the antibiotic is nephrotoxic (eg gentamicin),because serum levels increase and cause other side effects (e.g. levofloxacin) or because the antibiotic may be less effective (e.g. nitrofurantoin)
- The Renal Drug Handbook is available on Ward D8, RU and CC and by clicking the link below. It is also possible to request access to www.renaldrugdatabase.co.uk through the knowledge network. The doses from this reference source may not always mirror those in the BNF or other reference sources, but are taken from practice and considered to be the most reliable available.
- Note Renal Drug Handbook doses are based on Cockcroft-Gault creatinine clearance and not eGFR, since the majority of published information available is based on creatinine clearance. Note both eGFR and CC perform less well at extremes of body weight and are much less accurate when renal function is not stable. Review doses frequently to ensure an appropriate response..
- Doses are based on chronic renal impairment. In the early stages of AKI, it may be more appropriate to give full doses of some antibiotics especially where severe infection or sepsis is involved. If in doubt, ask for advice.
- Doses for patients on renal replacement therapies (RRT) are not given here. The monographs for many of the drugs recommend dosing as for eGFR <10, however different types of RRT have different effects on drug clearance so it is best to check with the renal team before prescribing
- Doses below are taken from the online Renal Drug database accessed 1st August 2020 with the exception of levofloxacin which is taken from the SPC
Aciclovir for Herpes Simplex or Zoster (Oral)
Renal Function | Dose (Simplex) | Dose (Zoster) |
Normal | 200-400mg 5x daily for 5 days | 800mg 5x daily for 7 days |
GFR 25 - 50 | Dose as in normal renal function | Dose as in normal renal function |
GFR 10 - 25 | 200mg every 6-8 hours | 800mg every 8-12 hours |
GFR<10 | 200mg every 12 hours | 400-800mg every 12 hours |
Aciclovir for HSV Encephalitis IV
Renal Function | Dose |
Normal | 10mg/kg every 8 hours for 10 days |
GFR 25-50 | 5 - 10mg/kg every 12 hours for 10 days |
GFR 10 - 25 | 5 - 10mg/kg every 24 hours for 10 days |
GFR <10 | 2.5 - 5mg/kg every 24 hours for 10 days |
Note there is no suitable oral switch – 10 day course should be completed IV when diagnosis confirmed. Patient should be well hydrated to avoid precipitation of crystals in renal tubules causing reversible AKI |
Benzylpenicillin IV
Renal Function | Dose |
Normal | 2.4 - 14.4g daily in 4-6 divided doses |
GFR 20 - 50 | Dose as in normal renal function |
GFR 10 - 20 | 600mg - 2.4g every 6 hours depending on severity of infection |
GFR <10 | 600mg - 1.2g every 6 hours depending on severity of infection |
Cefotaxime IV
Renal Function | Dose |
Normal | 1g every 12 hours (mild), 1g every 8 hours (moderate), 2g every 6 hours (severe) and up to 12g daily in 3 - 4 divided doses for life threatening infection |
GFR 5 - 50 | Dose as in normal renal function |
GFR <5 | Reduce dose by 50% but keep frequency the same |
Ceftazidime IV
Renal Function | Dose |
Normal | 1 - 2g every 8 - 12 hours. severe infection 3g every 12 hours, Pseudomonas lung infection in CF 100 - 150mg/kg daily in 3 divided doses |
GFR 31 - 50 | 1 - 2g every 12 hours |
GFR 16 - 30 | 1 - 2g every 24 hours |
GFR 6 - 15 | 500mg - 1g every 24 hours |
GFR <5 | 500mg - 1g every 48 hours |
Ceftriaxone IV
Renal Function | Dose |
Normal | 1g every 24 hours (moderate), 2 - 4g every 24 hours (severe infection) |
GFR 10 - 50 | Dose as in normal renal function |
GFR <10 | Dose as in normal renal function, max dose 2g daily |
Ciprofloxacin Oral/IV
Renal Function | Dose |
Normal | ORal 250 - 750mg every 12 hours, IV 100 - 400mg every 8 - 12 hours |
GFR 30 - 50 | Dose as in normal renal function |
GFR 10 - 30 | 50 - 100% of normal dose |
GFR <10 | 50% of normal dose, 100% dose may be given for short periods in exceptional circumstances |
Patients with renal impairment are at increased risk of rare but serious adverse effects of quinolones: Drug Safety Update so use with caution |
Note bioavailability of oral ciprofloxacin if high - 70-80% |
Clarithromycin
Renal Function | Dose |
Normal | Oral & IV 500mg every 12 hours |
GFR 30 - 50 | Dose as in normal renal function |
GFR 10 - 30 | 250 - 500mg every 12 hours |
GFR <10 | 250 - 500mg every 12 hours - vomiting may be a problem with higher dose |
Use oral route where possible as IV Clarithromycin can be irritant to the veins. Many drug interactions some serious so check before prescribing |
Clindamycin Oral/IV
Renal Function | Dose |
Normal | Oral 150 - 450mg every 6 hours, IV 600mg - 4.8g daily in 2 - 4 divided doses |
eGFR 10 - 50 | Dose as in normal renal function |
eGFR <10 | Dose as in normal renal function but prolonged half life may require a reduced dose |
Co-amoxiclav Oral/IV
Renal Function | Dose |
Normal | Oral 375 - 625mg every 8 hours, IV 1.2g every 8 hours increased to every 6 hours in severe infection |
GFR 30 - 50 | Dose as in normal renal function |
GFR 10 - 30 | IV 1.2g every 12 hours, Oral dose as in normal renal function |
GFR <10 | IV 1.2g stat followed by 600mg every 8 hours or 1.2g every 12 hours, Oral dose as in normal renal function |
Flucloxacillin Oral/IV
Renal Function | Dose |
Normal | Oral 500mg every 6 hours, IV 1 - 2g every 6 hours |
GFR 10 - 50 | Dose as in normal renal function |
GFR <10 | Dose as in normal renal function, maimum 4g daily |
Monitor for deterioration in renal function on 2g dose and consider reducing to 1g if necessary. For patients <50kg, usual maximum 4g daily. |
Fluconazole Oral/IV
Renal Function | Dose |
Normal | 50 - 400mg daily (up to 800mg has been used, but unlicensed) |
GFR 10 - 50 | 50-100% of normal dose |
GFR <10 | 50% of normal dose |
Oral bioavailability 90%. No dose adjustment required for single dose therapy. many drug interactions so always check before prescribing |
Gentamicin IV
Click here to see the section on Gentamicin
Levofloxacin Oral/IV
Normal renal function: Oral/IV 250-500mg every 12-24 hours
| Dose Regimen |
| 250mg/24 hours | 500mg/24 hours | 500mg/12 hours |
Creatinine Clearance | First dose: 250mg | First dose: 500mg | First dose: 500mg |
50-20ml/min | then: 125mg/24 hours | then: 250mg/24 hours | then: 250mg/12 hours |
19-10ml/min | then: 125mg/48 hours | then: 125mg/24 hours | then: 125mg/12 hours |
<10ml/min | then: 125mg/48 hours | then: 125mg/24 hours | then: 125mg/24 hours |
Patients with renal impairment are at increased risk of rare but serious adverse effects of quinolones:
Drug Safety Update so use with caution.
Meropenem IV
Renal Function | Dose |
Normal | 500mg - 1g every 8 hours up to 2g every 8 hours in meningitis and CF |
GFR 26 - 50 | 500mg - 2g every 12 hours |
GFR 10 - 25 | 500mg - 1g every 12 hours or 500mg every 8 hours |
GFR <10 | 500mg - 1g every 24 hours |
Metronidazole Oral/IV
Renal Function | Dose |
Normal | Oral 200 - 400mg every 8 hours, IV 500mg every 8 hours |
GFR <10 - 50 | Dose as in normal renal function |
Increased incidence of GI reactions and vestibular toxicity in renal failure.
Nitrofurantoin Oral
Renal Function | Dose |
Normal | Oral 50mg immediate release (IR) qds |
GFR 45 - 60 | Dose as in normal renal function but see caution below |
GFR <45 | Avoid |
Anecdotally, nitrofurantoin may be used at GFR 40 – 60ml/min but with increased risk of treatment failure due to inadequate urine concentration and side effects.
Rifampicin Oral/IV
Renal Function | Dose |
Normal | 300 - 600mg every 12 hours |
GFR 10 - 50 | Dose as in normal renal function |
GFR <10 | 50 - 100% of normal dose |
Reduce dose if LFTs are abnormal or patient <45kg. Check for drug interactions before prescribing as rifampicin is a strong inducer of CYP450 and has many serious drug interactions.
Tazocin (Piperacillin/Tazobactam) IV
Renal Function | Dose |
Normal | 4.5g every 8 hours, increase to every 6 hours in neutropenic sepsis |
GFR 40 - 50 | Dose as in normal renal function |
GFR 20 - 40 | 4.5g every 8 hours |
GFR <20 | 4.5g every 12 hours |
Patients with renal impairment are at a greater risk of neuromuscular excitability or convulsions that are associated with overdose.
Trimethoprim Oral
Renal Function | Dose |
Normal | Treatment: 200mg every 12 hours, Prophylaxis: 100mg nocte |
GFR 15 - 50 | Dose as in normal renal function |
GFR <15 | 50 - 100% of dose |
Serum creatinine may rise due to competition for renal secretion. Hyperkalaemia is common in CKD 5 and transplant patients. Short term folic acid supplementation may be prescribed in patients with CKD 4-5 to cover antifolate effects of treatment dose.
Vancomycin IV
Click here to see the section on Vancomycin
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