Screen includes amphetamines, benzodiazepines, cocaine, opiates, and oxycodone/oxymorphone. A presumptive positive result for any of the tested drugs indicates the possible presence of the drug or metabolites in the urine, but does not measure the level of intoxication. If confirmation is needed for amphetamines, benzodiazepines, cocaine, opiates, or oxycodone/oxymorphone, call the Laboratory at 356-3527. Allow up to seven days for confirmatory results. Confirmation is at an additional charge. The drug of abuse-urine panel was changed April 12, 2010 by the addition of the oxycodone screen and no longer including a screen for THC. If testing for THC is desired, see "THC, Urine Screen" or "THC, Urine Screen + Reflex Confirmation. The drug of abuse panel was further changed August 30, 2010 by no longer including a screen for barbiturates. If testing for barbiturates is desired, see "Barbiturates, Urine Screen". The individual components of the drug of abuse-urine screen can also be ordered individually, if desired (see links at end). Test Cut-off Concentrations (ng/mL) ------------------------------------------------------------- Amphetamines 1,000 Benzodiazepine 100 Cocaine 300 Opiate 300 Oxycodone 300 Additional information on approximate cut-offs for individual drugs or drug metabolites in the specific assays AMPHETAMINES ASSAY Drug Approximate cut-off for amphetamines assay (ng/mL) ------------------------------------------------------------- d-Amphetamine 981 d-Methamphetamine 1,000 d-Pseudoephedrine* 261,000 Ephedrine* 308,000 MBDB 1,175 MDA 771 MDEA 1,553 MDMA ("Ecstasy") 509 Phendimetrazine* 138,000 Phentermine* 239,000 Abbreviations for the "designer" amphetamine and methamphetamine derivatives: MBDB - methylbenzodioxolylbutanamine ("Eden") MDA - 3,4-methylenedioxyamphetamine MDEA - 3,4-methylenedioxy-N-ethylamphetamine ("Eve") MDMA - 3,4-methylenedioxymethamphetamine ("Ecstasy") * The concentrations of these compounds needed to trigger a positive amphetamines screen are very high and likely only achievable in large overdose. New amphetamines assay instituted 7/7/10. Unlike the assay used prior to 7/7/10, the new assay has very good cross-reactivity for MDMA (Ecstasy) and other designer amphetamines (MDA, MBDB, MDEA). The older assay did not cross-react well with amphetamines other than amphetamine and methamphetamine. The new assay has low cross-reactivity with non- amphetamine drugs (ephedrine, pseudoephedrine, phentermine, etc.). There have been several patients at University of Iowa Hospitals and Clinics where the amphetamines screen is positive and the suspected cause is the use of labetalol, a beta-blocker drug used to treat hypertension. In two of these patients, the amphetamines confirmatory test was negative, suggesting the absence of amphetamines. The manufacturer of the assay has tested labetalol and found it not to cross-react with the amphetamines screen; however, there is literature showing that labetalol metabolites can cross-react with some amphetamines assay. Consequently, the use of labetalol should be considered as a potential cause of false positive amphetamine screening results. If clinically indicated, confirmatory testing can be performed. BENZODIAZEPINES ASSAY Drug Approximate cut-off for benzodiazepines assay (ng/mL) ------------------------------------------------------------- Alprazolam* 119 Clonazepam* 270 Diazepam 82 Eszopiclone No cross-reactivity Lorazepam* 337 Midazolam 132 Nordiazepam (metabolite) 100 Zolpidem No cross-reactivity *In patients taking typical therapeutic doses of these benzodiazepines for medical purposes, the benzodiazepines screen can often be negative due to the low concentrations of these drugs and their metabolites excreted in urine relative to the cut-offs. COCAINE ASSAY Drug or drug metabolite Approximate cut-off for cocaine assay (ng/mL) ------------------------------------------------------------- Benzoylecgonine (metabolite) 300 Cocaine 21,200 Ecgonine methyl ester (metabolite) 326,000 Lidocaine No cross-reactivity* Procaine No cross-reactivity* *In general, local anesthetics do not cross-react with the cocaine immunoassay. OPIATES ASSAY Drug or drug metabolite Approximate cut-off for opiates assay (ng/mL) ------------------------------------------------------------- Buprenorphine No cross-reactivity Codeine 224 6-Acetylmorphine (heroin metabolite) 386 Fentanyl No cross-reactivity Heroin 366 Hydrocodone 1,086 Hydromorphone 1,425 Meperidine > 100,000 Methadone No cross-reactivity Morphine 300 Oxycodone > 75,000* *Therapeutic use of oxycodone in the absence of any other opiates is unlikely to result in a positive opiates screen. OXYCODONE ASSAY* Drug Approximate cut-off for oxycodone assay (ng/mL) ------------------------------------------------------------- Oxycodone 300 Oxymorphone 291 *The oxycodone assay does not cross-react with opiates other than oxycodone or oxymorphone (e.g., codeine, heroin, hydrocodone, hydromorphone, morphine) or with synthetic opioids (e.g., fentanyl, meperidine, methadone, propoxyphene). References: Belson MG, Simon HK, Sullivan K, Geller RJ. The Utility of Toxicologic Analysis in Children with Suspected Ingestion. Pediatr Emerg Care 1999;15:383-387. Bast RP, Helmer SD, Henderson SR, Rogers MA, Shapiro WM, Smith RS. Limited Utility of Routine Drug Screening in Trauma Patients. South Med J 2000;93:397-399. Hammett-Stabler CA, Pesce AJ, Cannon DJ. Urine Drug Screening in the Medical Setting. Clinica Chimica Acta 2002;315:125-135. Schiller MJ, Shumway M, Batki SL. Utility of Routine Drug Screening in a Psychiatric Emergency Setting. Psychiatric Services 2000;51:474-478. Sugarman JM, Rodgers GC, Paul RI. Utility of Toxicology Screening in a Pediatric Emergency Department. Pediatric Emergency Care. Pediatric Emergency Care 1997;13(3):194-197.