Analgesia : In Renal Failure

*Beginning dose: If switching from IR to ER, calculate 24-hour total dose.

**For patients with creatinine clearances (CrCl) of 15 mL/min or less, the daily dosage should be adjusted proportionally (e.g. patients with a CrCl of 7.5 mL/min should receive one-half the dose of a patient with a CrCl of 15 mL/min).

 Paracetamol

• Analgesic of choice for elderly patients or those with impaired renal function. In therapeutic doses, renal toxicity is rare. 
• There is no need for dose adjustment in renal failure, but some authors recommend increasing dose intervals from 6 to 8 hours when GFR is below 10 mL/min.

NSAIDS

• are well known to have direct nephrotoxic effects including renal vasoconstriction and clinically significant reduction in GFR via renal prostaglandin inhibition, interstitial nephritis with or without the nephrotic syndrome; fluid and electrolyte abnormalities including hyponatraemia, hyperkalaemia, type 4 renal tubular acidosis and other complications including oedema, hypertension and acute or chronic renal papillary necrosis. 
• If NSAIDS must be used, aspirin, the agent with the lowest adverse effect on glomerular filtration, may be considered. 
• Nevertheless, it is still advisable to extend the dosing frequency from every 4 h to 4–6 h.

Opioids

• Tramadol is generally preferred for moderate pain in CKD patients because it is not known to be directly nephrotoxic. 
• Nonetheless, it must be noted that its systemic elimination is reduced with advanced CKD (GFR <30 ml/min/1.73 m2). 
• The significant renal retention of active or toxic metabolites of commonly used opioids including, but not limited to, morphine, oxycodone and propoxyphene can occur among advanced CKD patients and lead to profound central nervous system and respiratory depression and hypotension. 
• Dose reduction for most opioids in patients with reduced renal function must therefore be considered to avoid drug accumulation and associated complications.

References

1. http://www.the-hospitalist.org/article/how-to-manage-pain-in-patients-with-renal-insufficiency-or-end-stage-renal-disease-on-dialysis/2/
2. http://ckj.oxfordjournals.org/content/2/2/111.full