The upper and lower brackets for morphine, codeine, hydromorphone, hydrocodone, and oxycodone in Figure ​Figure3B3B represent estimated steady-state urine concentrations in a 70 kg individual during chronic administration of daily 60 mg oral dose of codeine, 10 mg intramuscular dose of morphine, 5 mg oral dose of hydromorphone, 10 mg oral dose of hydrocodone,

or Inhibitors,research,lifescience,medical 20 mg oral dose of oxycodone, respectively [49]. As can be seen in Figure ​Figure3B,3B, the steady-state urine concentrations for all drugs except oxycodone will generally exceed the cutoff equivalent to 300 ng/mL morphine. For oxycodone, only 3 of 7 marketed assays have sensitivities to oxycodone sufficient to readily detect daily use of 20 mg oral oxycodone. Exact urine concentrations of oxymorphone following either oxymorphone or oxycodone administration have not been reported in the

literature but are likely Inhibitors,research,lifescience,medical to be well below the assay sensitivities due to the extensive metabolism of oxymorphone prior to renal excretion [50,51]. The upper bracket for 6-AM is the highest peak 6-AM urine concentration observed in a study of controlled heroin administration [52]. Marketed opiate assays do not cross-react with the mixed opiate agonist-antagonist buprenorphine (Tanimoto Inhibitors,research,lifescience,medical similarity to http://www.selleckchem.com/products/Adrucil(Fluorouracil).html morphine = 0.783) (Additional file 1, tab N). Commonly used non-opiate opioid drugs (e.g., fentanyl, meperidine, methadone, propoxyphene) generally have low structural similarity to morphine (Tanimoto similarity range = 0.407 – 0.522) and either do not cross-react, or do so only at Inhibitors,research,lifescience,medical Inhibitors,research,lifescience,medical extremely high concentrations, with opiate screening immunoassays (Additional file 1, tab N). Phencyclidine assays As a drug of abuse in the United States, PCP has waxed and waned in popularity

over time, with substantial regional differences in usage of this drug [53]. There are five well-documented cross-reactive compounds with PCP immunoassays: dextromethorphan, venlafaxine [14-16], meperidine, thioridazine, and mesoridazine (Additional file 1, tab P), although high urine concentrations of these drugs are generally required to elicit a positive PCP screening result most (Figure ​(Figure4A;4A; brackets indicate urine concentrations of PCP in patients abusing PCP [54]). While prescriptions for the latter three drugs have declined in the United States over the last decade, venlafaxine is widely prescribed in the United States (55th most prescribed drug in 2008) [29], and dextromethorphan continues to be widely used as both a prescription and over-the-counter medication in anti-tussive remedies (Table ​(Table3)3) [29].