Trial of Dronabinol and Vaporized Cannabis in Chronic Low Back Pain

Inclusion Criteria: Age greater than 18. Presence of chronic low back pain (CLBP) defined as the response to two questions 1) How long has back pain been an ongoing problem for you? 2) How often has low back pain been an ongoing problem for you over the past 6 months? A response of greater than 3 months to question 1 and a response of "at least half the days in the past 6 months" to question 2 will define CLBP according to the NIH Task Force on Research Standards for Chronic Low Back Pain. The numerical pain intensity must be greater than 3/10 each day during the one-week observation period. To avoid confounding by concurrent medications, participants will have had a stable analgesic regimen that they will continue throughout the study To obviate residual neuropsychological effects from cannabis exposure, participants will be abstinent from this herbal medicine for 7 days prior to study entry. Exclusion Criteria: Presence of another painful condition of greater severity than the neuropathic pain condition which is being studied. History of traumatic brain injury. Clinically significant or unstable medical condition. Individuals with significant cardiovascular, hepatic or renal disease, uncontrolled hypertension, and chronic pulmonary disease (eg, asthma, COPD), will be excluded. If warranted clinically, subjects will undergo laboratory evaluation (blood chemistry, electrocardiogram, urinalysis, toxicology screening for confirmation. Females of childbearing potential will undergo pregnancy testing. A positive result on toxicity screening will exclude individuals from participation. A urine drug test that screens for 5 categories of drugs: marijuana (Δ9-THC), cocaine, amphetamines/methamphetamines, opiates, benzodiazepines and phencyclidine (PCP) will be employed. A positive result for opioids and/or THC will not be exclusionary if the patient is receiving a prescription for an opioid and/or THC. Allergy to sesame oil, lactose, or gelatin Vascular disease, especially Raynauld's syndrome, systolic blood pressure \> 170 mm, diastolic blood pressure \> 100 mm Recent injuries to the upper extremity Cognitive impairment, such as Dementia or Alzheimer's Disease Substance Abuse History: The Substance Abuse Module of the Diagnostic Interview Schedule for the Diagnostic and Statistical Manual (DSM)-IV will be administered to exclude individuals with current substance use disorders. Pregnancy as ascertained by a mandatory commercial pregnancy test Past history of suic…