Table 1.

Recent clinical trials that target adenosine receptors associated with chronic pain (clinicaltrials.gov).

Clinical trial	Sponsor	Route	Status
Clonidine verses adenosine to treat neuropathic pain [NCT00349921]	Wake Forest University (PIs: Eisenach & Rauck)	Intrathecal	Ongoing
Dose-response of adenosine for perioperative pain [NCT00298636]	Xsira Pharmaceuticals	Intravenous	Completed - no significant effect [23].
The study of GW493838, an adenosine A1 agonist, in peripheral neuropathic pain [NCT00376454]	GlaxoSmithKline	Not indicated	Completed as of 2006 - results not reported
Efficacy and tolerability of novel A2A agonist in treatment of diabetic neuropathic pain (Drug: BVT.115959) [NCT00452777]	Biovitrum	Oral	Completed–was well-tolerated but did not significantly improve pain symptoms (Biovitrum press releasea)
Analgesic efficacy and safety study of T-62 in subjects with postherpetic neuralgia (T-62 is an A1R allosteric enhancer [85]) [NCT00809679]	King Pharmaceuticals	Oral	Terminated because some patients experienced transient elevations in liver enzymes
Use of AMP to improve tissue delivery of adenosine [NCT00179010]	Vanderbilt University (PI: Biaggioni)	Intrarterial	Suspended, in process of renewing drug application

^ahttp://www.abnnewswire.net/press/en/50001/Biovitrum's.html

Abbreviations: PI, Principal Investigator