Meperidine is metabolized in the liver to various metabolites, primarily normeperidine, which is toxic and has a long half-life, five to 10 times longer than meperidine. Meperidine should not be used in patients with renal insufficiency or dialysis.3
Adjunctive therapeutic options. Lidocaine patches currently are only FDA indicated for postherpetic neuralgia but are used for a wide variety of local pain syndromes. Absorption of lidocaine is determined by the duration of application and the surface area over which it is applied. There is no appreciable accumulation of lidocaine or its metabolites in renal insufficiency; therefore, dose adjustments are not required.22,23
Gabapentin is FDA indicated for partial seizures and postherpetic neuralgia but is also used for a wide variety of neuropathic pain syndromes, including postoperative pain.24 Gabapentin is not metabolized and is excreted in the urine unchanged. Renal clearance of gabapentin is reduced by 40% and the elimination half-life is increased up to 52 hours in renal insufficiency, but it is dialyzable. Therefore, dose adjustments are required with gabapentin in patients with moderate to severe renal insufficiency, and supplemental doses should be administered in patients after receiving dialysis.25-27
Pregabalin is structurally related to gabapentin and is indicated for a variety of neuropathic pain conditions. Pregabalin is 90% excreted unchanged in the urine, and approximately 50% of drug is removed after four hours of hemodialysis. Dose adjustments are required in patients with moderate to severe renal insufficiency, and supplemental doses should be administered in patients after receiving dialysis.28
Antidepressant options. Amitriptyline, nortryptiline, and desipramine are the tricyclic antidepressants (TCAs) commonly used for neuropathic pain. TCAs are metabolized in the liver to inactive metabolites, with the exception of amitriptyline, which is metabolized to nortryptiline. Common side effects reported with TCAs include postural hypotension and anticholinergic side effects, such as constipation, urinary retention, blurred vision, dry mouth, delirium, and sedation. It is unlikely that the TCAs can be removed by dialysis. It is suggested that the dosage be reduced in renal insufficiency and that anticholinergic side effects be monitored.29
Source: Adapted from Nayak-Rao S. Achieving effective pain relief in patients with chronic kidney disease: A review of analgesics in renal failure. J Nephrol. 2011;24(1):35-40.
Back to the Case
The patient’s ankle pain was controlled with acetaminophen and lidocaine patches. For the neuropathic pain in his upper extremities, tramadol was started at 25 mg oral every 12 hours and increased to 50 mg oral every eight hours (below the maximum of 200 mg a day). The tramadol did not result in adequate pain relief, so gabapentin 100 mg at bedtime was initiated, then increased to twice daily over three days with some relief.