Toxicology false positives

Finally, a third type of argument is possible especially for the choices of disciplines that use and depend on costly experimental techniques (e.g., the 2-year bioassays of toxicology). The concern about false positive decisions implied by the requirement for small values of alpha regardless of the consequences probably reflects where toxicologists collectively strike a balance between the need for a broad front advance and scarcity of resources. 

Semiquantitative test strips for these two measurements are designed for use with human urine rather than that of laboratory animals and are of very limited value in toxicology studies. Elevation of urinary bilirubin in the urine is suggestive of hepatocellular dysfunction, but the test strips can react to give false positive results, particularly with rodent urine. 

A. Specific levels. Assays exist for semm and urine analysis, but are not generally available. In seven fatal infant cases, blood levels averaged 0.38 mg/L (range 0.10-0.95). Despite its stmctural similarity to opioids, dextromethorphan is not likely to produce a false-positive urine opioid immunoassay screen. However, it may produce a false-positive result on methadone and phencyclidine immunoassays. Dextromethorphan is readily detected by comprehensive urine toxicology screening. 

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