Figure 3

Variability in sensitivity of marketed cocaine metabolite and opiate screening immunoassays. The plotted circles indicate the concentration of compound that produces equivalent reaction to 300 ng/mL benzoylecgonine (cocaine metabolite assays) or 300 ng/mL morphine (opiate assays). The dashed lines bracket clinically or toxicologically relevant concentrations from studies in the published literature (see text of Results for detailed description). A) Cocaine metabolite assays. Marketed cocaine metabolite detect benzoylecgonine with high sensitivity but generally have low sensitivity for detection of cocaine (parent drug) and metabolites other than benzoylecgonine. B) Opiate assays. Marketed opiate assays detect morphine, codeine, and hydrocodone well but have variability and often poor sensitivity to oxycodone and oxymorphone.