Plasma Concentration of Ketamine and Norketamine .

About This Study

Oral ketamine is increasingly used by doctors to both reduce the amount of narcotic pain medication consumed and to improve chronic pain management in difficult cases. How much is absorbed when taken orally, as opposed to intravenously ,is unknown. Ketamine may cause sedation, and occasionally cognitive impairment. Therefore, there are safety concerns associated with its usage as an out-patient may engage in activities where cognitive impairment is dangerous,such as driving. This study is designed to measure the plasma concentrations of ketamine and its active metabolite, norketamine, in people taking low dose oral ketamine for chronic pain. The goal of the study is to verify that low dose oral ketamine produces plasma concentrations below the level associated with toxic symptoms,and thus can be safely used long-term for the treatment of chronic pain .

Conditions Studied

Interventions

• •Ketamine

Eligibility

Inclusion Criteria:

* Patient currently takes oral ketamine for the treatment of chronic neuropathic pain.
* Age \>18 and \< 75 years
* Both males and females 4.Ability to speak English adequately to understand the consent and participate in the study
* No other route of ketamine within past 7 days (Topical/IV)

Exclusion Criteria:

* Patient receiving liver enzyme inducers or inhibitors of Cytochrome CYP3A4, or CYP2B6 like clarithromycin, rifampin, and recent ingestion of grapefruit juice.
* Patients who have had gastric bypass surgery
* Patients who did not follow the prescribed protocol
* Renal Failure defined as Creatinine Clearance \<50 mL/min
* Hepatic insufficiency by history

Study Locations (1)