Neuropathic Pain. Clinical Trial
Official title:
Plasma Concentrations of Ketamine and Norketamine in Patients Using Topical Application of 10% Ketamine for Neuropathic Pain.
The purpose of this research study is to measure how much, if any, ketamine is absorbed into
the blood stream after ketamine gel is applied to the skin. The investigators expect that
the topical administration will provide pain relief locally, at the site of pain, but not be
absorbed into the bloodstream and thus not cause side effects. This research will help
assess the safety of this drug by measuring the blood concentrations of the drug.
Ketamine is a general anesthetic drug but also has excellent pain relieving qualities. It
has been used to relieve chronic pain by administering intravenously, by mouth, or as an
injection beneath the skin. When given these ways ketamine can occasionally cause side
effects like dizziness, nausea, nightmares, agitation, hallucinations. Recently it has been
used topically for patients with neuropathic pain in order to avoid the dizziness and nausea
side effects.
Neuropathic Pain can be partially caused by the misfiring of small nerve fibers close to the
area of pain. By applying it on the skin, it is expected the drug can penetrate the skin and
act directly on the small nerve fibers. The advantage is that less drug will get into the
blood circulation. Up to now, it has not been carefully studied how much of the drug appears
in the circulation after application on the skin.
| Status | Recruiting |
| Enrollment | 15 |
| Est. completion date | December 2011 |
| Est. primary completion date | December 2011 |
| Accepts healthy volunteers | No |
| Gender | Both |
| Age group | 18 Years to 80 Years |
| Eligibility |
Inclusion Criteria: - Patients with peripheral, focal neuropathic pain such as or complex regional pain syndrome following surgery, bony, soft tissue trauma or nerve trauma, associated with significant allodynia and hyperalgesia who score equal to or greater than 4 in the DN4 questionnaire. - Duration of pain more than 3 months. - Ability to speak English adequately to consent to and participate in the study Exclusion Criteria: - Allergy to ketamine - Severe medical illnesses like, e.g. unstable angina, tachyarryhthmias, renal or hepatic failure - History of psychosis. - Patients who are already on oral ketamine treatment. - Patients who are taking HIV Antiretrovirals: (indinavir, nelfinavir, ritonavir saquinavir); Antibiotics: (clairithromycin, itraconazole, ketoconazole, telithromycin,fluconazole, erythromycin); Calcium Channel Blockers (verapamil, diltiazem),Amiodarone, Ciprofloxacin. (These drugs inhibit CYP 3A4 enzyme which metabolises ketamine) |
Observational Model: Case-Only, Time Perspective: Prospective
| Country | Name | City | State |
|---|---|---|---|
| Canada | Pain Clinic, St. Joseph's Health Care London Hospitals | London | Ontario |
| Lead Sponsor | Collaborator |
|---|---|
| Lawson Health Research Institute |
Canada,
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