Q: I received a report with a positive result for Buprenorphine by immunoassay (EIA) and a negative result by Mass spectrometry (MS). Which is the correct patient result?
A: Immunoassays can give false positive results, which is why Mass spectrometry is used to confirm all drug test results. In this case, the Mass spectrometry result is the definitive correct result. In the near future, our reports will only reflect the confirmed Mass spectrometry results.
Q: If a patient is receiving morphine by intrathecal (in the spinal cord) administration, will the urine drug test be positive?
A: Yes, the test will be positive. Spinal fluid is replaced every several hours and the drug will be metabolized and excreted primarily as the glucuronide.
Q: What metabolites are formed by the different opiates prescribed to patients?
A: Here is a chart that shows those opiates and their metabolites:
| DRUG | METABOLITES |
|---|---|
| Oxycodone | Noroxycodone, Oxymorphone, Oxycodyl |
| Morphine | Morphine-3-glucuronide, Morphine-6-glucuronide, Normorphine, Codeine, 7,8-Dihydromorphinone |
| Fentanyl | Norfentanyl, 4-N-(N-propionylanilino) piperdine, 4-N-(N-, 1-(2-phenethyl)-4-N-(N- Hydroxyproprionylanilino) piperdine |
| Hydromorphone | Hydromorphone-3-glucuronide, Hyrdomorphone-3-glucoside, Dihydroisomorphine-6-glucuronide, Dihydroisomorphine-6-glucoside, Dihydroisomorphine, Dihydromorphine |
| Codeine | Morphine, Norcodeine, Normorphine, Hydrocodone, Codeine 6-glucuronide |
| Hydrocodone | Hydromorphone, Norcodeine, 6-beta-hydrocodol, 6-alpha-hydrocodol, 6-beta-hydromorphol,6-alpha-hydromorphol |
| Methadone | EDDP (2-ethyl-1,5-dimethyl-3, -3-diphenylpyrrolinium), EMDP (2-ethyl-5-methyl-3, 3-diphenylpyraline) |
| Heroin | 6-acetylmorphine, Morphine, Morphine-3-glucuronide, Normorphine, 6-acetylmorphine 3-glucuronide, Normorphine glucuronide |
Q: My patient is on a benzodiazepine. Will the drug test measure the drug in urine?
A: Our drug testing will detect most benzodiazepines. Their metabolism is complex. Many benzodiazepines form nordiazepam and oxazepam, others such as temazepam and lorazepam can be measured directly. We recommend that the reader refer to the web-site http://www.etfrc.com/benzos1.htm for more details on benzodiazepine metabolism.
Q: My report says Fentanyl by E.I.A. is positive and Fentanyl by mass spectrometry negative. The report also says Mass Spectrometry overrules E.I.A.. The report reads positive for Norfentanyl. How do I interpret the results?
A: The immunoassay measures both Fentanyl and Norfentanyl. Urinary excretion of Fentanyl is about one-tenth that of Norfentanyl. Therefore, in this case the Fentanyl was less than the Mass Spectrometry cutoff, but Norfentanyl was above the cutoff because it is the major metabolic product of Fentanyl patches. The patient is definitely testing positive for Fentanyl in urine.
Q: Can the Mass Spectrometer screen for every drug a patient may be taking?
A: The Mass Spectrometer can screen for many drugs but not all. In the case of Millennium Laboratories we have focused our mass spectrometers to identify and quantify the drugs taken by pain management patients. In this circumstance, we use highly accurate deuterated forms of the drugs which are the most specific and quantitative ways of determining drugs in their concentration. We are focused on these drugs to give the highest quality of results. We do not test for every drug a patient may be taking.
Q: My patient’s imunoassay test is negative but the mass spectrometry result is positive. How can this occur?
A: Immunoassays have cutoffs set at levels that can detect the presence of a drug AND its metabolites, whereas mass spectrometers have cutoffs which are set lower in order to detect EACH of that drug’s metabolites. For example, a patient is taking codeine. The immunoassay shows that they are positive for the class of drugs termed opiates. On the Mass Spec the patient sample tests positive for Codeine, morphine, and hydrocodone at lower levels than the immunoassay.
Q: Fentanyl is an opiate like compound, why does it not show up on the i-cassette screen-opiate screen?
A: The antibodies for the opiate screen do not react with Fentanyl even though it is an opiate like compound. We do a separate antibody test to screen for Fentanyl.
Q: My patient who is an athlete tested positive for amphetamine by immunoassay and the positive was confirmed by your Mass Spec, though he did not test positive for MDMA or Methamphetamine. Is it possible the patient's performance enhancing vitamins and supplements caused the positive amphetamine test result?
A: Yes. Based on the fact that the patient was negative for both MDMA and Methamphetamine, it is very possible that amphetamine-like performance-enhancing substances were in the patient's body and that it was those substances that were detected. A number of herbals and performance-enhancing drugs contain amphetamine-like compounds that can react with our screening immunoassay. The LC-MS/MS confirms that the patient was not taking an illegal drug.
Q: Is it possible for a patient with a yeast infection to test positive for ETOH?
A: A positive urine alcohol may result from fermentation of the sample (not alcohol use) when glucose is present in the sample. Diabetes is a common cause of urinary glucose and the urine alcohol that results. A yeast infection alone without glucose would not be expected to produce alcohol.
Q: My patient is on Norco. Your test results came back strongly positive for morphine. Is this possible?
A: No. Norco is Hydrocodone. It can not be converted into morphine. The patient is probably obtaining morphine from another source.
Q: A patient told me at her last office visit that she had stopped taking her prescribed Hydrcodone five days ago. Her Point of Care Screen showed negative as well as the confirmation at your lab. Why wasn't a trace amount of Hydrocodone found on the confirmation?
A: The estimated half-life of Hydrocodone is up to 8 hours. After five days 15 half-lives will have lapsed, therefore all of the drug will have washed out of the body. The drug observation and the history are consistent.
Q: In my office, the patient testing results on the point of care drug cassette are all negative. Can I discard the rest of the urine?
A: No! You should submit it for more inclusive testing. The point of care tests only examine the urine for a limited number of tests. Drugs such as fentanyl, SOMA, buprenorphine and some others used and abused by pain patients cannot be found using these devices. Tests for these drugs are performed by specialized laboratories such as Millennium. In addition, the cutoffs of point of care devices are higher than those obtained by the more sensitive LC-MS/MS tests. Thus patients with lower but confirmable concentrations will not be diagnosed. Finally, point of care devices can be deceived by adulterants, yielding false negative results. Often times these agents will not deceive the mass spectrometer. Thus the point of care testing is only the first step of the process to define the patient’s drug status. Further testing is recommended.
Q: One of my patients tested positive for amphetamine, but negative for methamphetamine. Could this be an error caused by over-the-counter medications?
A: No, this could not be an error. The LC-MS/MS analysis is specific for amphetamine. A more detailed medical history may help identify the source of the amphetamine. Only if the patient lists an over-the-counter medication or herbal supplement containing amphetamine would this drug be found by LC-MS/MS analysis.
Q: Our patient has been prescribed SOMA and Oxycontin. The results are negative. Should we confront the patient with diversion?
A: The following information must be considered. Was the point of care device (POC) negative for oxycontin? Did the physician office request “Confirm negative results”? For the SOMA, did the physician office have a physician signed request to confirm all negative tests?
If the POC device was negative, the confirming EIA also negative and finally the MS result as negative, then all are consistent with the patient not taking the drug. They can be confronted with this. The lab data supports noncompliance or diversion. For SOMA, if the EIA test result is negative no further analyses are done unless the physician has requested a negative confirmation by MS. We do not recommend confronting the patient with only EIA data. Ask for MS confirmation data. This will require filling out the added test form. If this is negative then all are consistent with the patient not taking the drug. They can be confronted with this. The lab data supports noncompliance or diversion
Q: My patient is taking Clonazepam. Why don’t I see a positive result on the Point-of-Care Test?
A: The Point-of-Care tests have limited reactivity with some benzodiazepines. Currently, the benzos that react poorly or DO NOT react include: Bromazepam, Chlordiazepoxide, Clonazepam, Delorazepam, Estazolam, Lorazepam, Midozelam, and Triazelam. In order to get definitive results, the physician should request a “Confirm All Negative” Screen from Millennium Laboratories. In many cases the presence of the drug is confirmed by its metabolites. We measure those metabolites: Nordiazepam, Oxazepam, and Temazepam.
Q: Our patient is on a fentanyl patch and the drug test came back negative. Why did this happen?
A: In part this is due to the low dose of fentanyl given to patients and the fact that only 26 to 55% is recovered in urine as the metabolic product norfentanyl. Very little of the parent drug fentanyl is recovered. Considering a 12 microgram per hour patch given over 72 hours and an average urine output of 1.5 liters, we would expect to find about 24ng/mL of norfentanyl in the urine. This is near our cut-off. Patches with higher doses would be more easily detectable. The 26-55% recovery in urine is only an estimate. We know that people vary considerably in their metabolism, so that negative results at higher doses will occur in some patients.
Q: Millennium Laboratories reported an alcohol value of 290 mg/dL. What does this translate to with respect to blood level?
The usual conversion factor is 1.3 to convert to the blood level. The value may then be divided to convert to gram percent. In this case the blood level is 0.223 gram percent. In many states the patient would be considered to be drunk.
Millennium Laboratories
16981 Via Tazon
San Diego, CA 92127
Toll Free: 877-451-3534
Fax: 858-451-3636