Clinical trial NCT00349921: Clonidine Versus Adenosine to Treat Neuropathic Pain
Official title: Clonidine Versus Adenosine to Treat Neuropathic Pain
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
Conditions: Pain
Keywords: pain
chronic pain
clonidine
adenosine
complex regional pain syndrome
CRPS
a2-adrenergic agonists
alpha2-adrenergic agonists
Lead sponsor: Wake Forest University Health Sciences
Sponsor class: OTHER
Collaborators: name: National Institute of Neurological Disorders and Stroke (NINDS)
First posted: 2006-07-10
Enrollment: 24
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: The purpose of this study is to determine the effects of clonidine and adenosine on nerve pain.

Detailed description: This study is part of a pain center grant that focuses on how pain, especially chronic neuropathic pain, alters the response to traditional and non-traditional analgesics (pain medications).

Clonidine-a drug commonly used to treat high blood pressure-has been shown to effectively treat neuropathic pain, is FDA-approved for administration via epidural (an injection given in the lower back), and is the third most commonly prescribed drug for chronic intrathecal (an injection into the cerebrospinal fluid) use in people with chronic pain.

Adenosine-a drug commonly administered intravenously (into a vein) to treat certain types of abnormal heart rhythms-has been found to reduce areas of allodynia (pain caused by a stimulus that does not normally cause pain) after intrathecal, but not intravenous administration in people with neuropathic pain.

Intrathecal clonidine relieves pain by actions on a2-adrenoceptors in the spinal cord, whereas adenosine relieves pain by actions on A1 adenosine receptors. Researchers believe that intrathecal adenosine and clonidine may prove to be excellent painkillers for nerve pain. Therefore, the goal of this study is to determine the effects of clonidine and adenosine on nerve pain.

After initial screening, baseline measurements, and training to learn to estimate pain accurately using thermal heat testing, a sample of spinal fluid will be taken from each participant. Participants then will be randomly chosen to receive either clonidine, adenosine, or placebo. After receiving the study medication, participants will be monitored, with their vital signs checked at 30, 60, 120, 180, and 240 minutes.

Duration of the study for participants is 2 weeks, and includes two visits to the research center, each lasting approximately 6 hours.

Eligibility criteria: Inclusion Criteria:

* Patients with complex regional pain syndrome (CRPS), type I involving a lower extremity

Exclusion Criteria:

* Pregnancy
* Allergy to clonidine
* Currently taking clonidine or other direct a2-adrenergic agonists, or taking cholinesterase inhibitors
* Patients with any serious or unstable medical problems (heart, lung, liver, kidney, or nervous system disease)

Primary outcomes:
measure: Number Meeting Success Criterion
timeFrame: baseline and 2 hours
Secondary outcomes:
Other outcomes:
Locations:
city: Winston-Salem
country: United States
facility: The Center for Clinical Research, 145 Kimel Park Drive
state: North Carolina
city: Winston-Salem
country: United States
facility: Wake Forest University School of Medicine, Medical Center Boulevard
state: North Carolina
Study officials:
affiliation: Wake Forest University Health Sciences
name: James C. Eisenach, M.D.
role: PRINCIPAL_INVESTIGATOR
affiliation: The Center for Clinical Research
name: Richard Rauck, M.D.
role: PRINCIPAL_INVESTIGATOR
References: