Two types of test cards are being offered for UDT, both of which differ only in regard to how the specimen is being handled:
1. The dip test - Remove the cap from the test device and hold the absorbent tip into the urine for 10-15 s. There is no protective cap with every single test (Figure V-10).
2. The drop test - Using a pipette 3 drops are dropped into each well (Figure V-10). Read the result after 5-10 min.
Different Multi-Test Cards, either as a dip or a drop-test are available which can be selected in different compositions and combinations for individual drug testing (Figure V-11): Opiates/Opioids, Cocaine, COC 200, Benzodiazepines, Methadone, THC, THC 25, Amphetamines, Barbiturates, TCA Methamphetamine. Buprenorphine, Ecstasy (3,4-Methylendioxy-N-methylamphetamine), AMP 300, MET 300, and EDDP. Since EDDP (2-ethylidine-1, 5-dimethyl-3, 3-diphenyl-pyrrolidine; Figure V-12) is the main metabolite from methadone. By detecting the metabolite
c COC MET THC
COC MET THC
Example: All parameters are negative.
Example: The parameter Cocaine (COC) is positive.
If the control line "C" is not visible, the test is invalid.
Figure V-11. How a Multiple-Test card should be interpreted (AMP = amphetamine; MOR = morphine; COC = cocaine; MET = methamphetamine; THC = tetrahydrocannabinol)
rather than methadone itself, during substitution therapy one has following advantages:
1. Submission of foreign urine with methadone addition is no longer possible. By adding methadone to a negative urine sample, the methadone test will have a positive reading and the patient could make the methadone usage appear believable. Because the EDDP test only reacts highly sensitively to the
methadone metabolites, any attempt at manipulation remains negative. Those who metabolize quickly will be reliably detected. 2. Some patients metabolize methadone into EDDP very quickly. In such a case, the methadone test still remains negative, because there is no cross-reaction to the EDDP metabolite. With the EDDP test, however, these patients can be reliably identified.
In addition to Multiple-Test Cards, single test strips (i.e. sticks; Figure V-13) are also available for the qualitative detection of following abusable substances: Amphetamines, Barbiturates, Benzodiazepines, Buprenorphine, Cannabinoides, Cocaine, EDDP, Methadone, Methamphetamines, Opiates, PCP (phencyclidine), or TCA (tricyclic antidepressants). Having dipped the stick into the urine sample for 5-10 s, results can be viewed after 5-10 min.
Also, a Cocaine Trace Wipe is available (Figure V-14), which has been developed in cooperation with Police and Customs Authorities for the determination of cocaine residues on all surfaces such as inside cars, baggage, containers, parcels, textile (jeans etc.). If there are traces of cocaine, there will be a reaction on the tissue (blue color).
Although the specific determination of an antibody only reacts to an antigen, it can occur that a molecule with a very similar structure causes a reaction, leading to false results. Affected patients know this effect and consistently claim that a new medication must be the reason for a positive urine result. A commonly known cross-reactivity is that of codeine to opiates. A patient who takes codeine will test positive for opiates, because the molecules are so similar in structure that the antibodies can't tell the difference. A GC/MS (gas chromatography/mass spectroscopy) confirmation analysis helps in the situation to detect 6-Acetylmorphine as a primary substance, which is a metabolite of heroine, but not of codeine. The results should be available in the lab within 2 working days after receipt of the sample. In the case of a positive result, an approximate quantification will be done. Additionally, the detected illicit substance will be further differentiated, for instance for the type of benzodiazepine. Furthermore, polydrug use, such as LSD and buprenorphine can also be detected.
In the case of a positive result, this can only be considered a rough quantification of an abused substance. In the case of amphetamines, barbiturates, benzodiazepines, opiates or tricyclic antidepressants (TCA), the specific substance is only detected qualitatively. Furthermore, the concomitant ingestion of other illicit drugs can be identified. In the case of cross-reactivity, further tests should be conducted in order to clarify the situation. In case of additional drug abuse such as designer drugs, LSD and/or buprenorphine, it is also possible to use gas chromatography or HPLC (high pressure liquid chromatography) for analysis.
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