Acute pain in patients with renal or hepatic impairment

The metabolism and excretion of many analgesic drugs will be altered in the presence of renal or hepatic impairment. Some analgesic drugs can cause renal or hepatic damage. Protein binding of drugs may be altered by hepatic reduction in production or uraemic displacement from binding sites. In renal disease, paracetamol is the simple analgesic of choice. Morphine can be used with care in mild to moderate renal disease, but fentanyl or oxycodone may be better alternatives. Non-steroidal anti-inflammatory drugs should be avoided in renal disease. In hepatic disease with significant impairment, doses of morphine must be reduced and the dosage interval lengthened. Fentanyl should be avoided in severe hepatic disease.