Little is understood concerning the interaction of pain with sleep. Pain may disrupt sleep leading to daytime sleepiness and poor sleep can increase the perception of pain. There is uncertainty concerning the most effective way in which medication could be used to ease pain and poor sleep in patients such as those with diabetic peripheral neuropathy. Various drugs have been tried or proposed, and these include amitriptyline, pregabalin and duloxetine.~Amitriptyline is believed to relieve pain and improve sleep, though there is little evidence of its beneficial effects on sleep. Furthermore, even at low doses, it affects reaction time, attention, memory, information processing.~In two studies with duloxetine, it has been shown to significantly reduce pain compared with placebo, although little data are available on the usefulness of this compound in the management of pain with poor sleep.~Pregabalin has been shown to be effective in reducing pain, and therefore improving sleep. It has also been demonstrated that it has limited potential to affect daytime cognition. In another study gabapentin (a compound structurally related to pregabalin) demonstrated superior efficacy in the management of pain compared to amitriptyline.~Therefore this study will assess the effectiveness of pregabalin, duloxetine and amitriptyline compared with placebo in reducing pain associated with diabetes and poor sleep.~As the incidence of diabetes is predicted to increase in future years and as a consequence so will the cases of diabetic peripheral neuropathy (DPN), this research will serve to provide essential information on sleep and DPN which will be beneficial now and in the future.
The purpose of this study is to assess the effectiveness of pregabalin, duloxetine and amitriptyline compared with placebo in reducing pain in diabetic patients as assessed by Brief Pain Inventory (BPI).