Effective pain relief in patients with end-stage renal failure can be difficult to achieve. The active metabolites of many opiates are renally-excreted and side effects are more common in patients with end-stage renal failure. In particular, confusion and drowsiness limit their use. Similarly drugs commonly used for neuropathic pain, such as gabapentin, have not be investigated in clinical trials in patients with end-stage renal failure (Kurella et al., 1993).