Prescribing

Doses and intervals of many drugs are altered in renal failure and should always be checked in the BNF or Renal Drug Handbook. Renal pharmacists are the best sources of information on anything non-routine and happy to be contacted for advice.

Important examples of drugs that require special consideration are:

ACE inhibitors / ARBs Drugs within these classes may cause hyperkalaemia in renal failure (check in 3 and 7 days if high risk), and a steep decline in function in renal artery stenosis (check creatinine in 1 week or in 4 and 10 days if high risk). Re-checks should be undertaken after substantial increases in dose, or if loop diuretics are added or increased. Note: Only a 20-30% rise in creatinine should be regarded as significant; a small rise is normal. UK CKD Guidelines recommend accepting a cautious 20% (15% reduction in eGFR) after introducing ACEi or ARB. See how to start an ACE inhibitor for more information.

Antibiotics – see antimicrobial prescribing for more detail

Gentamicin – Should generally be avoided in acute kidney injury. Can be given to haemodialysis patients as per a renal-specific protocol (click here to download).

Nitrofurantoin – Should not be prescribed if eGFR<60. It causes peripheral neuropathy and will be ineffective for treating UTI’s due to inadequate urine concentration.

NSAIDs – Should generally be avoided in significant renal impairment, though in mild/moderate CKD they can be used after discussion and with monitoring if alternatives are much less effective.  Avoidance is not essential for dialysis patients but risk of GI bleeding is probably already increased in ESRD and so caution is advised. Use of NSAIDs for prolonged periods may irreversibly reduce native urine output for patients on haemo- or peritoneal dialysis, and this may have long term implications for their fluid balance.

Opiates – The effects of almost all except for fentanyl are very much prolonged in renal failure. There is great potential for active metabolites to accumulate. These can have significant adverse effects. It is recommended to avoid modified-release preparations, opting instead for low dose immediate-release drugs with careful monitoring for adverse effects. 

Heparin – LMWHs are renally excreted and should be used with caution in patients with CKD stages 4-5 or AKI. There is increased risk of bleeding and monitoring of anti-Xa activity should be considered. Unfractionated herapin is advised by some for patients with EGFR<25ml/min. Dose reduction of LMWH in patients with renal impairment is required, if used. Please see anticoagulation or VTE prophylaxis pages for more information.

Vancomycin – Dosing in dialysis patients is based upon monitoring of trough levels, click here for the haemodialysis protcotol.

Further information:

 

Acknowledgements:   Caroline Whitworth and Lorna Thomson were the main authors for this page. The last modified date is shown in the footer.

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