10th July 2026

Analgesics

Opiates

Morphine is problematic in renal impairment, as opioid effects are prolonged, and active metabolites are prone to accumulation. Pethidine is contraindicated as there is increased risk of seizures from the accumulation of norpethidine. The first line strong opioid should be oxycodone, however this also has partial renal excretion, as well as prolongation of its half-life, so requires dose reduction. 

Fentanyl and alfentanil may be a safer alternatives as they are metabolised to inactive and nontoxic metabolites and are not significantly renally excreted. Patients should be monitored closely for signs of toxicity. For medium to long-term analgesia use, prolonged-release oxycodone may be used in mild to moderate CKD; however, may cause problems in stages G4-5 CKD. It may be more suitable to administer transdermal fentanyl or buprenorphine, as they are not renally excreted.

Non-steroidal anti-inflammatory drugs (NSAIDS) 

NSAIDS should be avoided in renal impairment, as they can cause a rapid deterioration in renal function. As they are effective in nociceptive pain associated with inflammation, where there is a strong indication for them, they can be trialled as a last resort and with close monitoring in patients with mild or moderate CKD. Topical formulations should be used with caution and over a small surface area. 

Gabapentin and pregabalin 

Anticonvulsants are useful for neuropathic pain. Caution should be exercised when administering these in renal impairment, as they are renally excreted and require dose if creatinine clearance is < 80 mL / minute for gabapentin and ≤ 60 mL / minute for pregabalin. Patients should be closely monitored for neurologic side effects. 

Amitriptyline 

Tricyclic antidepressants, which are also useful for neuropathic pain, are not renally cleared and, therefore, can be used at usual doses.