title: Marijuana correlates with use of other illicit drugs in a pain patient population.
abstract: BACKGROUND
  A significant number of chronic pain patients may use marijuana. Physicians treating those patients can benefit by knowing whether their patients using marijuana are at higher risk for using other illicit drugs such as cocaine and/or methamphetamine.
  
  
  OBJECTIVE
  Our objective was to determine whether marijuana-using chronic pain patients have a higher incidence of cocaine and/or methamphetamine use.
  
  
  METHODS
  A retrospective study of the incidence of pain patients using marijuana and/or other illicit drugs such as methamphetamine and cocaine versus the incidence of pain patients not using marijuana but using methamphetamine and/or cocaine.
  
  
  METHODS
  Urine specimens from chronic pain patients were analyzed by LC-MS/MS to determine the co-occurrence of these abused substances.
  
  
  RESULTS
  In this study 21,746 urine specimens were obtained from chronic pain patients. We found a 13.0% incidence of patients positive for the acid form of Tetrahydrocannabinol (THCA). The percentage of those positive for cocaine was 4.6%, those positive for methamphetamine totaled 1.07%. Using both chi-square and a Logistic Regression analysis, we determined that there was a correlation between marijuana use and the use of other illicit drugs. The odds ratio was > 3.7 for other illicit drug use.
  
  
  CONCLUSIONS
  The study is limited in that we obtained no data as to the causal relationships of this type of drug use.
  
  
  CONCLUSIONS
  Pain physicians should be aware that this relationship exists and marijuana-using patients are at greater risk for use of other illicit drugs although no causal relationship is implied. Increased monitoring of these patients may help minimize potential morbidity due to drug interactions as well as identify patients who may be diverting prescriptions in order to pay for illicit drugs.
authors.affiliation: Millenium Laboratories Research Institute, San Diego, CA 92127, USA.
authors.forename: Amadeo
authors.initials: A
authors.lastname: Pesce
authors.forename: Cameron
authors.initials: C
authors.lastname: West
authors.forename: Murray
authors.initials: M
authors.lastname: Rosenthal
authors.forename: Robert
authors.initials: R
authors.lastname: West
authors.forename: Bridgit
authors.initials: B
authors.lastname: Crews
authors.forename: Charles
authors.initials: C
authors.lastname: Mikel
authors.forename: Perla
authors.initials: P
authors.lastname: Almazan
authors.forename: Sergey
authors.initials: S
authors.lastname: Latyshev
authors.forename: Paul S
authors.initials: PS
authors.lastname: Horn
mesh_terms: D002188:Cannabis; D016009:Chi-Square Distribution; D002908:Chronic Disease; D013759:Dronabinol / Q000652:urine; D006801:Humans; D013287:Illicit Drugs / Q000652:urine; D016015:Logistic Models; D008694:Methamphetamine / Q000652:urine; D010146:Pain / Q000188:drug therapy* / Q000652:urine; D012189:Retrospective Studies; D018570:Risk Assessment; D015813:Substance Abuse Detection / Q000379:methods
chemical_list: D013287:Illicit Drugs; D008694:Methamphetamine; D013759:Dronabinol